Preliminary survey of the nearshore coastal marine ......To everyones hero, Warwick Crowe, whose...

Preliminary survey of the nearshore coastal marine

environment of the south coast of East Timor: a baseline for assessing the impacts of a developing

nation

Alex S.J. Wyatt

Bachelor of Engineering (Applied Ocean)

Centre for Water Research

University of Western Australia

A thesis submitted in partial fulfilment of the requirements of the

Bachelor of Engineering at the University of Western Australia

(November 2004).

One man s biodiversity is another man s lunch

-Pacific Islander to visiting scientist (Carrascalao, 2001)

If you start a new nation with all this garbage, what s it gonna end up with?

-UN representative on East Timor s development (Sandlund et al., 2001)

Preliminary survey of the coastal marine environment of East Timor iii

Abstract The potential pollution of tropical marine environments bordering coastlines

as a result of population growth and development is widely acknowledged. Coastal

marine environments and resources in developing nations are particularly susceptible,

being closest to concentrations of population and industry, being areas popular for

recreation, and having a wealth of exploitable resources. The urgent need for

development and a lack of financial resources means that many developing countries

operate on the premise of development first, mitigation and treatment later . With

the world s biodiversity centred in the tropics, where human-induced impacts have

already affected about one third of the world s coral reefs and up to 50% of the

world s mangrove systems, the threat to biodiversity from unplanned development is

significant.

The need for development is nowhere more urgent than in East Timor, which

is one of the poorest nations in the developing world. Since independence was

declared on the 20th of May 2002 political effort has been focused on recovering from

destruction following the 1999 independence referendum, and on gaining a sound

financial footing for the nation. With large potential income to be gained from

exploitation of the natural environment, such as through coffee agriculture, oil and gas

production, and nature-based tourism, there is significant potential for degradation of

the marine environment if the impacts of development are not assessed and managed.

This study represents a preliminary step towards redressing the paucity of

knowledge about East Timor s marine environment. Undertaken as part of a broader

multi-disciplinary research program, the overarching aim of the study was to provide

baseline data in an extremely data poor region and thereby assist management of the

nation s natural resources. More specifically, the study was focused on assessing the

nearshore coastal marine environment around the village of Betano and the potential

for impacts from development in an area currently subject to little development

pressure outside of subsistence agriculture. The study was undertaken in two parts

with surveying of coastal sediments and intertidal biota.

Firstly, coastal sediments were surveyed in order to: (a) assess the extent of

linkage between land-based sources of pollution and the marine environment using

the relative contributions of terrigenous and biogenic material; and (b) assess

nearshore transport mechanisms, and hence the fate of material from land-based

Preliminary survey of the coastal marine environment of East Timor iv

sources in the nearshore zone. The flux of terrigenous sediments was strongly evident

in both coastal sediment composition and sediment cores. The transport and fate of

terrigenous sediment in the nearshore zone requires further investigation. Sediment

composition also indicated that a thriving coral community occurs offshore.

Secondly, intertidal biota was surveyed to: (a) document the biota of a coastal

habitat in the region for the first time; and, in doing so, (b) determine if anthropogenic

activities have impacted this biota via fluvial flux of sediments and contaminants, and

(c) explore survey techniques for rapidly assessing marine ecosystems, particularly

those applicable for use in developing nations with little infrastructure or financial

resources. The potential for using photographic survey techniques was evident.

However, simple visual assessment was found to be more efficient due to a

prevalence of cryptic species. Sampling revealed a total of 27 taxa of sessile

organisms composed of 18 taxa of algae, three sponges (poriferans), two coral

(scleractinians), two ascidians, one anemone (cnidarian) and one foraminifer. The

influence of fluvial flux was not strongly evident, apart from apparent species-specific

responses of a brittle star (ophiuroid) and an ascidian to organic matter input from

seasonal rivers. Variations in reef topography seem to be the most important factor

shaping community composition and the reef appeared to be in a pristine state little

impacted by land-based activities.

The study demonstrates that anthropogenic impacts on the nearshore marine

environment in this region currently appear to be minimal. However, a variety of

developments are likely to occur in the region as East Timor attempts to gain a sound

economic footing and as coastal populations grow. Land-based developments,

construction of infrastructure such as marinas and jetties, oil and gas exploration,

fishing, vessel traffic and tourism are all identified as threats to the region s marine

environment. This study is a preliminary step towards obtaining baseline data

essential for assessing and managing the impacts of these developments. Although

representing a significant logistical challenge, further investigation in the region is

required in order to assist sustainable development of East Timor and defy the global

trend of environmental degradation resulting from development. Sustainable

development will directly benefit the nation s population as, if maintained in a pristine

state, the marine environment represents a significant economic resource.

Preliminary survey of the coastal marine environment of East Timor v

Acknowledgements

I would like to thank a number of people for their assistance in making this project a

reality:

Firstly, my supervisors Anya Waite and David Haig. Anya in particular provided

helpful advice and guidance throughout, particularly during what looked like being

project-ending disasters.

Myra Keep who initiated and organised the entire research programme, giving so

many students the opportunity to study and experience East Timor.

Conaco-Phillips for providing flights to and from Dili.

To everyone s hero, Warwick Crowe, whose super-human patience and endurance

saw him run the field camp and juggle everyone s research requirements, putting his

own last, for more than two months.

Grey Coupland for her assistance in getting the project off the ground and focusing

my field effort. Without Grey s help the project would not have been a success.

Thank you also for your assistance since returning from Timor.

To the entire field team who made the trip such an enjoyable experience. Particularly,

Halinka for here enthusiasm and Mr Eguidio, Gaspar and Ele for their help in the field.

Finally to Anna and my family, thanks for all your love and support throughout.

Preliminary survey of the coastal marine environment of East Timor vi

Table of Contents Page No.

TITLE PAGE ..........................................................................................................................................1

ABSTRACT..........................................................................................................................................III

ACKNOWLEDGEMENTS ..................................................................................................................V

TABLE OF CONTENTS .................................................................................................................... VI

LIST OF FIGURES ..........................................................................................................................VIII

LIST OF TABLES .................................................................................................................................X

1. INTRODUCTION.........................................................................................................................1

2. LITERATURE REVIEW.............................................................................................................6

2.1. TROPICAL MARINE ENVIRONMENTS.......................................................................................6 2.1.1. Mangroves.........................................................................................................................8 2.1.2. Coral reefs ......................................................................................................................11 2.1.3. Soft Bottom and Intertidal Habitats ................................................................................15 Soft Bottoms Habitats....................................................................................................................15 Intertidal Habitats .........................................................................................................................16

2.2. DEVELOPMENT AND MARINE ENVIRONMENTAL IMPACTS....................................................17 2.2.1. Land-based activities ......................................................................................................18 Effects of Altered Nutrient Input....................................................................................................19 Effects of Altered Sediment Input ..................................................................................................20 Effects of Altered Freshwater Input ..............................................................................................22 2.2.2. Physical alteration ..........................................................................................................22 2.2.3. Fishing ............................................................................................................................23 2.2.4. Oil and gas exploration and production .........................................................................24 2.2.5. Tourism ...........................................................................................................................25 Direct Impacts of Tourism.............................................................................................................26 Indirect Impacts of Tourism ..........................................................................................................27 Mitigation of Tourism Impacts ......................................................................................................27 2.2.6. Shipping activities ...........................................................................................................28

2.3. BASELINE SURVEY TECHNIQUES FOR DEVELOPING NATIONS ..............................................28

3. CHARACTERISATION OF COASTAL SEDIMENTS: ORIGIN AND FATE...................33

3.1. INTRODUCTION .....................................................................................................................33 3.2. MATERIALS & METHODS......................................................................................................34

3.2.1. Study Site & Sampling Design ........................................................................................34 3.2.2. Qualitative Analysis ........................................................................................................35 3.2.3. Sediment Sampling & Analysis .......................................................................................35

3.3. RESULTS...............................................................................................................................39 3.3.1. Qualitative Analysis ........................................................................................................39 3.3.2. Sediment Grain Size ........................................................................................................43 3.3.3. Sediment Composition.....................................................................................................43 3.3.4. Sediment Cores ...............................................................................................................43

3.4. DISCUSSION..........................................................................................................................46 3.4.1. Conclusions.....................................................................................................................49

4. BASELINE SURVEY OF INTERTIDAL BENTHIC BIOMASS AND COMPOSITION: AN ASSESSMENT OF RAPID SURVEY TECHNIQUES AND ANTHROPOGENIC IMPACT

50

4.1. INTRODUCTION .....................................................................................................................50 4.2. MATERIALS & METHODS......................................................................................................52

4.2.1. Study Site.........................................................................................................................52 4.2.2. Sampling Design .............................................................................................................52 4.2.3. Image Analysis ................................................................................................................53

Preliminary survey of the coastal marine environment of East Timor vii

4.2.4. Sediment Chlorophyll Analysis .......................................................................................56 4.2.5. Data Analysis ..................................................................................................................56

4.3. RESULTS...............................................................................................................................61 4.3.1. Physical Parameters .......................................................................................................61 4.3.2. Visual/Digital Comparison .............................................................................................61 4.3.3. Sessile Taxa.....................................................................................................................62 4.3.4. Ophiuroid........................................................................................................................63 4.3.5. Sediment Chlorophyll......................................................................................................63

4.4. DISCUSSION..........................................................................................................................71 4.4.1. Conclusions.....................................................................................................................80

5. DISCUSSION ..............................................................................................................................81

5.1. CONCLUSIONS ......................................................................................................................83 5.2. RECOMMENDATIONS ............................................................................................................84

5.2.1. Investigate taxonomy of intertidal reef biota ..................................................................84 5.2.2. Temporally and spatially extend current surveying ........................................................84 5.2.3. Survey other nearshore habitats .....................................................................................84 5.2.4. Investigate regional oceanography.................................................................................85 5.2.5. Planned monitoring of susceptible areas ........................................................................85 5.2.6. Public involvement in development and environmental protection.................................86 5.2.7. Restore degraded habitats...............................................................................................86

6. REFERENCES ............................................................................................................................87

APPENDIX A........................................................................................................................................97

APPENDIX B ......................................................................................................................................105

Preliminary survey of the coastal marine environment of East Timor viii

List of Figures

Page No.

FIGURE 1: STUDY REGION OF RESEARCH PROGRAMME SHOWING THE NEARSHORE COASTAL

ENVIRONMENT AROUND THE VILLAGE OF BETANO IN DETAIL. GEOLOGICAL AND GEOGRAPHICAL

STUDIES IN THE PROGRAM WERE CENTRED AROUND THE TOWN OF SAME APPROXIMATELY 40KM

INLAND FROM BETANO IN THE CABLAKE MOUNTAIN RANGE OF CENTRAL TIMOR. THIS STUDY WAS

FOCUSED ON THE SANDY BEACH ENVIRONMENT STRETCHING WEST OF BETANO TO THE MOUTH OF

THE RIVER QUELAN, AND ON THE EXTENSIVE INTERTIDAL REEF PLATFORM EAST OF THE VILLAGE.4 FIGURE 2: LOCATION OF THE SEVEN BEACH SEDIMENT SAMPLING SITES (S1

S7) WEST OF BETANO. SEE

CHAPTER FOUR FOR LOCATIONS OF REEF SAMPLING TRANSECTS AND RIVER AT WHICH CORES WERE

TAKEN. SEDIMENTS ANALYSED FOR GRAIN SIZE AND COMPOSITION TO DETERMINE THE RELATIVE

CONTRIBUTIONS OF TERRIGENOUS AND BIOGENIC MATERIAL ON BOTH THE BEACH AND IN THE

VICINITY OF THE INTERTIDAL REEF IN ORDER TO ELUCIDATE THE INFLUENCE OF FLUVIAL FLUX ON

THE NEARSHORE ZONE. ..................................................................................................................37 FIGURE 3: SCHEMATIC REPRESENTATION OF LOCATIONS OF CORES ONE (C1) AND TWO (C2) ON A

TYPICAL BEACH PROFILE ABOVE THE INTERTIDAL REEF PLATFORM. GENERAL BEACH PROFILES

CONSISTED OF A SLOPING BEACH FACE STRETCHING FROM THE BASE OF THE INTERTIDAL REEF

PLATFORM AT MEAN LOW WATER LEVEL (MLWL) TO A BERM AT HIGH WATER LEVEL. BEHIND THE

BERM THE BEACH SLOPED DOWNWARDS INTO THE RIVER MOUTH. FOR BEACHES NOT ADJACENT TO

THE REEF OR RIVER MOUTHS, THE BEACH SLOPE WAS MORE PRONOUNCED AND THERE WAS NO

SLOPE BEHIND THE BERM, WITH VEGETATION BEGINNING AT HIGH WATER LEVEL. ........................38 FIGURE 4: SANDY BEACH ENVIRONMENTS OF THE SOUTH COAST OF EAST TIMOR AROUND BETANO

SHOWING (A) THE STEEP WAVE-EXPOSED BEACHES AND (B) THE TYPICAL BARRIER BAR FORMATION

AT RIVER MOUTHS FORCING SHORE PARALLEL WESTWARD FLOW OF RIVERS IN THE DRY SEASON. 40 FIGURE 5: CORAL SKELETONS COLLECTED AMONGST BEACH RUBBLE IN THE VICINITY OF T1 SHOWING

SEVEN DISTINCT SKELETAL MORPHOLOGIES, SUGGESTING A DIVERSE CORAL ASSEMBLAGE OCCURS

OFFSHORE OF THE INTERTIDAL REEF PLATFORM.............................................................................41 FIGURE 6: AERIAL PHOTOGRAPH OF: (A) THE STUDY REGION DEMONSTRATING THE INPUT OF SEDIMENT

INTO THE COASTAL ZONE; (B) CLOSE-UP OF THE MOUTH OF THE RIVER QUELAN SHOWING THE

APPARENT WESTERLY TRANSPORT OF SEDIMENT (LIGHT ARROW) (RED DOTS ARE SEDIMENT

SAMPLING LOCATIONS). EVIDENCE OF AREAS OF SIGNIFICANT DEFORESTATION ARE SHOWN BY

HEAVY ARROWS. SEE CHAPTER FOUR FOR SEDIMENTS IN VICINITY OF REEF PLATFORM FURTHER

EAST (FIGURE 21)...........................................................................................................................42 FIGURE 7: COMPOSITION OF SEDIMENTS COLLECTED FROM A BEACH SITE (S2) AND THE MIDDLE OF THE

INTERTIDAL REEF PLATFORM (T4-20), AS WELL AS SEDIMENTS ADJACENT TO THE REEF AT 10, 20 AND 30 M FROM THE REEF EDGE (S8, S9 AND S10, RESPECTIVELY)................................................44

FIGURE 8: COMPOSITE IMAGES OF CORES ONE (A) AND TWO (B), SCALE BAR REPRESENTS 5CM IN BOTH

INSTANCES. A CLOSE-UP OF ONE SECTION OF CORE ONE (C) SHOWS THICK BANDS OF DARK

TERRIGENOUS SEDIMENT ALTERNATING WITH THIN BANDS OF LIGHT BIOGENIC MATERIAL

(ARROWS). .....................................................................................................................................45 FIGURE 9: LOCATION OF THE SIX SAMPLING TRANSECTS (T1

T6) ON INTERTIDAL ROCK PLATFORM EAST

OF BETANO. NOTE THAT T3, T4 AND T5 ARE LOCATED AT THE MOUTH OF SMALL RIVERS AND T6 IS ADJACENT TO THE VILLAGE OF SALIHASAN. ...............................................................................54

FIGURE 10: INTERTIDAL REEF PLATFORM SHOWING: (A) TYPICAL ZONATION CONSISTING OF SANDY

BEACH DELINEATED FROM WAVE-CUT CARBONATE LIMESTONE PLATFORM BY BEACHROCK; AND

(B) EVIDENCE OF RELICT CORAL WHICH FORMED THE WAVE-CUT PLATFORM.................................55 FIGURE 11: EXAMPLES OF METHODOLOGY USED TO DIGITALLY DETERMINE MACROPHYTE COVER USING

THE NIH IMAGE J SOFTWARE: (A) ORIGINAL JPEG IMAGE IS CONVERTED TO (B) AN 8-BIT IMAGE

AND (C) THRESHOLDS APPLIED TO HIGHLIGHT THE AREAS OF BROWN ALGAE AND (D) LARGE

REGIONS OF BROWN ALGAE SUBJECTIVELY SELECTED (BLACK ARROWS) AND AREA CALCULATED........................................................................................................................................................57

FIGURE 12: SPECIES-AREA CURVE (BLACK LINE) FOR THE ENTIRE SURVEY SHOWING 95% CONFIDENCE

LEVELS (DASHED LINES). NOTE THE CURVE APPEARS TO BE NEARING AN ASYMPTOTE SUGGESTING

SAMPLING FULLY CAPTURED THE DIVERSITY OF SESSILE TAXA ON THE INTERTIDAL REEF PLATFORM........................................................................................................................................................65

Preliminary survey of the coastal marine environment of East Timor ix

FIGURE 13: AVERAGE SPECIES RICHNESS PER QUADRAT OF SESSILE TAXA FOR EACH OF THE SIX

TRANSECTS ACROSS THE INTERTIDAL REEF PLATFROM. .................................................................65 FIGURE 14: AVERAGE DIVERSITY (H ) FOR EACH OF THE SIX TRANSECTS INCREASING WEST (TRANSECT

ONE, T1) TO EAST (TRANSECT SIX, T6) ALONG THE INTERTIDAL REEF PLATFORM. .........................66 FIGURE 15: MDS PLOT BASED ON 4TH ROOT TRANSFORMED PERCENT COVER DATA DISCRIMINATING

QUADRATS BY TRANSECT (TRANSECT ONE: BLACK UPWARDS TRIANGLE; TWO: DOWNWARDS

TRIANGLE, THREE: BLACK SQUARE, FOUR: DIAMOND, FIVE: BLACK CIRCLE; SIX: CROSS). NOTE

LACK OF SEPARATION BY TRANSECT AND STRESS = 0.11................................................................66 FIGURE 16: AVERAGE PERCENT COVER AT EACH DISTANCE FROM THE SHORE FOR EACH TRANSECT.

COVER GENERALLY INCREASED WITH DISTANCE FROM THE SHORE. A NOTICEABLE DROP IN COVER

AT 20M FOR T3 COINCIDED WITH A ROCK POOL CONTAINING SIGNIFICANT WATER AT LOW TIDE. ..67 FIGURE 17: MDS PLOT BASED ON 4TH ROOT TRANSFORMED PERCENT COVER DATA DISCRIMINATING

QUADRATS BY DISTANCE FROM SHORE (0M = BLACK UPWARDS TRIANGLE, 10M = DOWNWARDS

TRIANGLE, 20M = BLACK SQUARE, 30M = DIAMOND, 40M = BLACK CIRCLE). NOTE SEPARATION OF

0M QUADRATS AND STRESS = 0.11. ................................................................................................67 FIGURE 18: AVERAGE NUMBER OF BRITTLE STARS (OPHIUROID) PER QUADRAT (25 × 25 CM) FOR T4

T6 DETERMINED FROM PHOTOGRAPHIC (DIGITAL) AND FIELD (VISUAL) COUNTS.................................70

FIGURE 19: SPATIAL PATTERN OF BENTHIC ALGAL BIOMASS, IN TERMS OF CHLOROPHYLL A AND

PHAEOPHTYIN, IN SEDIMENTS AT INCREASING DISTANCES FROM THE MOUTH OF THE RIVER

QUELAN (S1 - S7). SEE CHAPTER 3 FOR DETAILS OF SAMPLING SITES S1 - S7. ..............................70 FIGURE 20: A SPECIES OF BRITTLE STAR (OPHIUROID) WAS HIGHLY ABUNDANCE ALONG T4 WITH UP TO

80 M-1. NOTE THE ASSOCIATION OF BRITTLE STARS WITH SMALL OPENINGS IN THE REEF, WITH

MANY INDIVIDUALS LESS THAN HALF EMERGENT...........................................................................74 FIGURE 21: AERIAL PHOTOGRAPH OF: (A) THE STUDY REGION DEMONSTRATING THE INPUT OF SEDIMENT

INTO THE COASTAL ZONE, PARTICULARLY AT THE MOUTH OF THE RIVER QUELAN AND EDDY AT

HEADLAND EAST OF STUDY AREA SUGGESTING WESTERLY CURRENT; (B) THE REEF PLATFORM

SHOWING LOCATIONS OF SAMPLING POINTS (T1

T6, WEST EAST). ARROW DENOTES POSSIBLE

SEDIMENT IN REGION OF T4 AND T5...............................................................................................75

Preliminary survey of the coastal marine environment of East Timor x

List of Tables

Page No.

TABLE 1: PHYSICAL PARAMETERS (PH, SALINITY AND TEMPERATURE) MEASURED AT EACH DISTANCE

ACROSS THE INTERTIDAL REEF PLATFORM FOR TRANSECTS ONE FOUR. MEASUREMENTS COULD

ONLY BE ACHIEVED WHERE SUFFICIENT WATER REMAINED AT LOW TIDE ......................................64 TABLE 2: RESULTS OF TWO-WAY NESTED ANOSIM TEST WITH DISTANCE NESTED WITHIN TRANSECT

SHOWING TRANSECTS SIGNIFICANTLY DIFFERENCE BY PAIRWISE TESTS.........................................68 TABLE 3: RESULTS OF SIMPER TEST IDENTIFYING SPECIES CHARACTERISTIC OF EACH TRANSECT

(AV.ABUND. = AVERAGE ABUNDANCE IN THAT TRANSECT, AV.SIM. = AVERAGE SIMILARITY, CONTIBUTION (%) = CONTRIBUTION TO WITHIN TRANSECT SIMILARITY, CUMULATIVE (%) = CUMULATIVE CONTRIBUTION TO SIMILARITY WITH CUT OFF SPECIFIED AT 30%). ..........................68

TABLE 4: RESULTS OF SIMPER TEST IDENTIFYING SPECIES RESPONSIBLE FOR SIGNIFICANT DIFFERENCES

BETWEEN TRANSECTS A AND B, AS REVEALED BY PAIRWISE ANOSIM TEST (AV.ABUND. = AVERAGE ABUNDANCE IN THAT TRANSECT, AV.DISS. = AVERAGE DISSIMILARITY BETWEEN

TRANSECTS, CONTIBUTION (%) = CONTRIBUTION TO BETWEEN TRANSECT DISSIMILARITY, CUMULATIVE (%) = CUMULATIVE CONTRIBUTION TO DISSIMILARITY WITH CUT OFF SPECIFIED AT

30%) ..............................................................................................................................................69 TABLE 5: RESULTS OF SIMPER TEST IDENTIFYING SPECIES CHARACTERISTIC OF EACH DISTANCE FROM

SHORE (AV.ABUND. = AVERAGE ABUNDANCE IN THAT TRANSECT, AV.SIM. = AVERAGE SIMILARITY, CONTIBUTION (%) = CONTRIBUTION TO WITHIN DISTANCE SIMILARITY, CUMULATIVE (%) = CUMULATIVE CONTRIBUTION TO SIMILARITY WITH CUT OFF SPECIFIED AT 30%). ..........................69

Preliminary survey of the coastal marine environment of East Timor 1

1. Introduction

The potential pollution of tropical marine environments bordering coastlines

as a result of population growth and development is widely acknowledged (Alongi,

1989; Gerges, 1994; Christie & White, 1997; Thia-Eng, 1999; Burgess, 2000; Bellan

& Bellan-Santini, 2001; de Jonge et al., 2002; Tran et al., 2002; Li & Daler, 2004).

Coastal marine environments and resources in developing nations are particularly

susceptible, being closest to concentrations of population and industry, being areas

popular for recreation, and having a wealth of exploitable resources (Alongi, 1989;

Gerges, 1994; Christie & White, 1997; Bellan & Bellan-Santini, 2001). The urgent

need for development and a lack of financial resources means that many developing

countries operate on the premise of development first, mitigation and treatment later

(Thia-Eng, 1999).

The need for development is particularly urgent in East Timor, which is

emerging as an independent state after 500 years of colonialism and foreign

occupation (Sandlund et al., 2001; Fox, 2003). First the Portuguese for over 400

years, followed by the Indonesians from 1975 to 1999, exploited natural resources of

the country for short term profits and introduced management practices without regard

for sustainability (Sandlund et al., 2001). In addition, violence following the 1999

referendum for independence has left the country with damaged infrastructure and

very little economic activity (Sandlund et al., 2001). In the short period post-

referendum, 70% of all houses and most infrastructure was destroyed, 75% of the

entire population displaced and many people killed (Sandlund et al., 2001; Macaulay,

2003). It is estimated that 50% of the population now live below the poverty line of

an income of USD 1 per day, although with 70% of people living in rural areas

dominated by subsistence agriculture it is difficult to express poverty in terms of

monetary income (Sandlund et al., 2001; Macaulay, 2003).

Given this backdrop of significant social and economic needs, focus on the

social and economic outcomes of developments that will aid the nation s recovery is

understandable (e.g. Hill & Saldanha, 2001). However, development in East Timor

represents a unique opportunity to also include environmental along with the more

typical social and economic considerations. While the principles of sustainable

development may be difficult to apply where the basic needs of life are not available


to all of the population (e.g. Hanson, 2001), using sustainability as the basis for

building the new nation has the potential to defy the global trend of environmental

degradation resulting from development (Anderson & Deutsch, 2001). In fact, a

healthy environment also has the potential to play an active role in economic recovery

of the nation and directly benefit the population. Industries such as organic coffee and

ecotourism have been identified as sources of significant potential income and will be

dependent on sustainable management of the natural resources of the country

(Anderson & Deutsch, 2001; Macaulay, 2003).

In the past, these natural resources were poorly managed by both the

Portuguese and Indonesian occupiers. Both periods of occupation have seen

significant environmental degradation. The Portuguese introduced foreign

agricultural practices and crops which, in combination with large-scale deforestation

continued during Indonesian occupation, has resulted in significant alteration of the

terrestrial environment (Soares, 2001; Fox, 2003). Deforestation is estimated to have

reduced forest area by close to 20% in the last 15 years (Bouma & Kobryn, 2004).

Resource use without regard for sustainability, damage during World War II and

independence fighting, and active and deliberate destruction by the retreating

Indonesians, has resulted in further environmental degradation of the terrestrial

system (Soares, 2001).

The extent to which the marine environment has been degraded along with the

terrestrial has been little explored. Knowledge about the environment in East Timor

is scarce but the marine environment is thought to be largely unspoilt (Sandlund et al.,

2001). However, similar to the terrestrial realm, a variety of types of degradation

have been documented anecdotally. Along with terrestrial species displaced by

deforestation, a number of marine species are thought to be endangered (Macaulay,

2003). The prevalence and destruction of blast fishing on coral reefs is acknowledged

(Carrascalao, 2001) and is evident on reefs even within sight of the capital city of Dili

(pers. obs.).

As development continues in the strive for economic recovery, there are a

number of further ways in which the marine environment may be impacted by human

activity. Sandlund et al. (2001) identifies two types of development pressure

occurring as a result of East Timor s recovery with the potential to impact the marine

environment. One pressure stems from the immediate need for reconstruction, which

leaves little opportunity to consider and plan for environmental impacts, the other


stems from the influx of foreign investment. East Timor is only now being opened up

to foreign investment with great economic potential, such as tourism and oil

exploration, which have the potential to impact the marine environment if not planned

for and managed (Sandlund et al., 2001). While development from foreign

investment is still of high economic priority, it does not have the same urgency as

reconstruction needs and there is the potential for more consideration to be given to

the potential for environmental impacts.

Another environmental consideration in the development of East Timor is the

increasing concentration of population in cities, particularly on the coast. In the mid-

1990s, more than 90% of the population lived in rural areas (Sandlund et al., 2001).

This has been rapidly changing recently, with estimates suggesting that 200,000

people now live in the coastal capital Dili (Sandlund et al., 2001). This has

significant implications for the marine environment (e.g. Tran et al., 2002). In the

nearby Indonesian island of Ambon, which already has a larger population than East

Timor, significant pollution of coastal waters has been detected (Evans, 1995). In the

Philippines, growth in coastal populations due to degradation of upland agricultural

regions led to increased pressure on coastal resources and subsequent environmental

degradation (Kuhlmann, 2002). Continued growth in coastal populations is likely to

increase pressure on East Timor s marine environment and resources.

Increased pressure and degradation of the marine environment is likely in turn

to directly impact the economic recovery of East Timor. Currently, impacts on the

marine environment are most likely to affect the poor segments of the population,

such as small-scale artisanal fishermen dependent on resources close to shore

(Sandlund et al., 2001). However, the nearshore coastal zone contains unique

resources of importance to the nation as a whole (Sandlund et al., 2001). For instance,

coral reef systems have the potential to generate significant income from tourism, but

only if maintained in pristine condition. Significant living and non-living resources in

the marine environment mean that informed management is of significant economic

and environmental importance to surrounding countries (Morrison & Delaney, 1996).

Currently, management of the marine environment surrounding East Timor is difficult

to achieve due to an almost complete lack of data and scientific knowledge (e.g.

Sandlund et al., 2001).


Figure 1: Study region of research programme showing the nearshore coastal environment around the village of Betano in detail. Geological and geographical studies in the program were centred around the town of Same approximately 40km inland from Betano in the Cablake mountain range of central

Timor. This study was focused on the sandy beach environment stretching west of Betano to the mouth of the River Quelan, and on the extensive intertidal reef platform east of the village.


This study was initiated in order to begin redressing the lack of information

about the status of the nearshore coastal marine environment. The study was

undertaken as part of a broader research programme also including geological and

geographical investigations. The overarching aim of the programme was to provide

baseline data in an extremely data poor region and thereby assist in management of

the nation s natural resources. The need for high quality data to support effective

policy design and implementation has been recognised as essential for sustainable

development in East Timor (Pires, 2001). The programme also provided an

opportunity for East Timorese counterparts to obtain hands-on training in techniques

for assessing and analysing their nation s natural resources, with university students

and staff from the government Departments of Minerals and Resources and

Environment assisting in the field programme.

In this study the nearshore coastal marine environment on the south coast of

East Timor is assessed for the first time. Investigation was focused around the village

of Betano, which along with its surroundings, is almost entirely rural, lacking running

water and power. The coastal zone is dominated by transmigration settlements from

Indonesian rule and inhabitants are largely dependent on slash and burn agriculture

and subsistence fishing (Sandlund et al., 2001). The study was undertaken in two

parts. Firstly, a survey was undertaken to document coastal sediments for the first

time. The origin and fate of these sediments was assessed in order to evaluate the

linkage between the terrestrial and marine environment and thereby elucidate the

potential for land-based activities to impact the nearshore environment. Secondly, the

biota of an extensive intertidal reef platform was surveyed in an attempt to detect

anthropogenic impacts on marine biota from potential land-based sources of pollution.

Survey techniques suitable for rapidly and easily assessing marine biota were also

explored with particular consideration given to the logistical constraints of working in

an infrastructure-poor remote region of a developing nation. Both phases of the study

also achieved the overarching aim of providing baseline data to assist in management

of the nation s natural resources.


2. Literature Review

This review will consider the tropical marine environment and potential

impacts that may result from anthropogenic activities. In addition methods for

describing marine environments and documenting changes resulting from human

impacts are discussed with reference to methods suitable for developing nations.

Many of the developing nations of the world occur in the tropics, and for a nation

such as East Timor, which faces severe economic hardship, there is greater potential

for adverse affects on the marine environment without informed management. In

many instances measuring and assessing environmental impacts is dependent on

accurate determination of baseline data collected prior to significant development.

This data is largely unavailable for developed nations, but many techniques exist that

may allow developing countries to quickly, easily and, most importantly, cheaply

assess the status of marine environments under their jurisdiction.

The coastal ecosystems considered in the review, largely coral reefs and

mangroves, typically form the major components of coastal tropical environments and

were considered a priori to be of similar importance in East Timor. While practical

and safety considerations meant that these ecosystems could not be directly

investigated in this study, the likely importance of coral reefs and mangroves to global

marine biodiversity, the structure and function of the nearshore coastal environment,

and the people of East Timor, as well as their susceptibility to the impacts of

development, still holds. In fact, the importance and susceptibility of coral reefs to

the impacts of development on the south coast of East Timor is indirectly established

in this study. For these reasons, the major marine ecosystems of the tropics, while not

the unit of study in this investigation, are considered important for framing the results

presented against a broader backdrop of potential impacts on the marine environment

in developing nations.

2.1. Tropical Marine Environments

In order to mitigate potential impacts an understanding of the general structure

and function of the major components of the marine environment is necessary.

Coastal tropical marine environments can be broadly classified into two major

biotopes, mangals (mangrove forests) and coral reefs, with associated soft bottom and

intertidal habitats (Alongi, 1989; Nybakken, 2001). Both biotopes are important to


human populations, providing ecosystem services and subsistence, particularly in

developing countries (Alongi, 1989; Ronnback, 1999; Mann, 2000). These

environments will form the basis of this review, in particular focusing on potential

impacts and assessment of coral reefs and, to a lesser extent, mangroves.

The importance of mangals to human populations through direct use and

ecological services is well documented. Mangroves have been used for centuries as a

source of fuel, food and housing, as well as many other items such as medicines,

paper and tannins to preserve fishing nets and leather (Alongi, 1989, 1998; Ronnback,

1999). In addition to direct benefits, mangals provide ecological services and have

close linkages to other tropical habitats. Mangals provide: protection from flood and

storm damage; provision of nursery, breeding and feeding grounds; a possible source,

dependent on hydrodynamics, of organic material to surrounding coastal areas;

maintenance of biological and genetic diversity; biological regulation of ecosystem

processes and functions; and a host of other services (see Ronnback, 1999).

Similar to mangles, coral reefs provide both direct benefits and ecosystems

services. In developing countries 25% of fish catch is obtained from coral reefs,

which provide up to 80% of animal protein in some countries (Wilkinson, 1996;

Mann, 2000). Given their small area, the fisheries yield of coral reefs is impressive at

roughly 6 million metric tons per year (Alongi, 1998). Like mangles, coral reefs also

provide protection from storms and erosion and a source of building material

(Wilkinson, 1996; Mann, 2000). Importantly for developing nations, coral reefs also

have the potential to provide a substantial revenue through tourism (Wilkinson, 1996;

Mann, 2000). Based on their value for food security, employment, tourism,

pharmaceutical research and shoreline protection, these reefs can have significant

economic value. For instance, reefs in Indonesia were estimated to provide economic

benefits valued at USD 1.6 thousand million in the year 2002 (DeVantier et al., 2004).

While mangals and coral reefs may seem greatly different in structure and

function they have close ecological linkages and origins. In fact, successful

development of mangrove forests depends in many instances upon initial colonisation

and establishment of reef building corals on hard substrates (Alongi, 1989, 1998).

With a shared requirement for warm (<15 ºC) air and ocean temperatures and shallow

water depths, mangrove forests and coral reefs have similar global distributions and

are ecologically linked (Alongi, 1989). For instance, the influence of mangroves in

stabilising water quality and sediment concentration in coastal waters may be


important for maintenance of coral reef communities (Ronnback, 1999), particularly

given the specialised requirements of coral reefs (see discussion below). As

mentioned, mangroves may provide nursery and breeding grounds for coral reef

species, as well as a potential source of nutrients (Ronnback, 1999; Ellison &

Farnsworth, 2001; Mumby et al., 2004). In a recent study, Mumby et al. (2004) found

that mangroves in the Caribbean strongly influence the community structure of fish on

neighbouring reefs by providing nursery habitats for juvenile fish. The authors found

that the biomass of certain commercially important fish species was more than

doubled in reefs connected to mangroves compared to those where mangroves had

been removed and concluded that current mangrove deforestation is likely to have

severe, deleterious consequences for ecosystem function, fisheries productivity and

resilience of nearby reefs. Preservation of tropical marine environments may be

dependent on an understanding of the structure and function of the individual

ecosystems, as well as how they are intrinsically linked.

2.1.1. Mangroves

The global distribution of mangroves is controlled by warm air and water

temperature and shallow water depths. Prior to anthropogenic disturbance, mangals

(mangrove forests) dominated 75% of the coastline between 25ºN and 25ºS (Alongi,

1989; Mann, 2000; Ellison & Farnsworth, 2001). On a local scale the distribution of

mangroves is dependent on four principle factors: (1) tidal inundation, (2) soil type,

(3) salinity of tidal water and soil, and (4) light (Alongi, 1989). The zonation of

mangroves can be divided according to the level of tidal inundation with species

composition across the intertidal changing as a result of differing tidal inundation

(Alongi, 1989; Ellison & Farnsworth, 2001). The zonation of mangroves can be

attributed to: interspecific differences in the tolerance of edaphic factors (physical or

chemical properties of soil affecting plant growth) that co-vary with tidal elevation;

sorting of dispersed propagules during stranding; inter-specific competition; and

frequency-dependent preferences of seed predators (Ellison & Farnsworth, 2001).

Mangals can be composed of a variety of life forms, from trees to shrubs and

even ferns (Ellison & Farnsworth, 2001). Mangrove species are flowering plants

coming from 12 genera in eight different families (Nybakken, 2001). The appearance

of mangroves varies according to geomorphology, storm disturbance and nutrient

status: from squat, scrubby shrubs to 40m tall forests (Ellison & Farnsworth, 2001).


Even individuals of the same species can have vastly different phenotypes depending

on edaphic and biotic conditions (Ellison & Farnsworth, 2001).

Despite the variety of phenotypes and species of mangroves, all share a

number of features allowing them to persist in saline environments and anoxic muds

(Ellison & Farnsworth, 2001). Common physiology, architecture and life history are

thought to be convergent solutions to evolutionary challenges presented by the

intertidal environment (Ellison & Farnsworth, 2001).

Mangroves utilise the C3 photosynthetic pathway, which, in comparison to the

C4 pathway, is less efficient, resulting in greater respiratory loss of fixed carbon and

reduced tolerance of high temperatures and light levels (Raven et al., 1992; Alongi,

1998). Given the high temperature and light levels in the tropics the use of the C3

pathway is puzzling and may indicate mangroves common ancestry with woody

terrestrial plants (Alongi, 1998). There is in fact evidence that mangroves may be

evolving towards the C4 pathway, with some species possessing C4 enzymes (Alongi,

1998). Mangroves use of the C3 pathway has a number of implications for water use

efficiency and behavioural adaptations.

Mangroves are much more efficient water users than other C3 plants and all

have physiological adaptations allowing them to obtain freshwater by maintaining

negative osmotic potential below that of saline water and preventing loss of

freshwater through transpiration (Alongi, 1998; Ellison & Farnsworth, 2001).

Adaptations assisting in reducing water loss include thick cuticles, and sunken or

hidden stomata (Alongi, 1998). Also, mangrove leaves are tough and succulent,

allowing for water storage and salt excretion through specialised salt glands (Alongi,

1998; Ellison & Farnsworth, 2001; Nybakken, 2001). Mangroves are also able to

exclude salt from entering the plant at the root, although this may act as a feedback

mechanism when salt concentrations in the sediment reach levels that limit the rate of

water uptake and hence photosynthesis (Alongi, 1998; Ellison & Farnsworth, 2001).

Architectural adaptations in mangroves are particularly evident in their root

systems and may be a response to both the salinity and anoxia of sediments in which

mangroves typically grow. Root systems including knees, pneumatophores, stilt roots

and plank roots with air pores allowing roots to receive oxygen and function in anoxic

muds (Ellison & Farnsworth, 2001; Nybakken, 2001). Estimates suggest that below

ground biomass accounts for roughly 50% of total mangle biomass (Alongi, 1998).


Mangroves have a physical requirement for minimal water movement and

actively reduce water velocity due to the physical presence of their trunks and

extensive exposed roots. This means that mangals are a zone of high sediment

deposition, with sediments settling out of the water column under low velocity. This

means that mangrove ecosystems are dominated by soft sediment environments,

however the mangroves themselves are also capable of growing on coral rock or sand

(Nybakken, 2001). Bioturbation in these environments, particularly by crabs, has

impacts on sediment chemistry, organic matter decomposition and may enhance the

productivity of mangroves (Alongi, 1998).

Mangles are often considered to be highly productive ecosystems, although

high biomass rarely mirrors rates of primary production and the presence of a

luxurious forest does not necessarily imply high production (Alongi, 1998). However,

measured rates of production do suggest that, within their optimal range, mangroves

can be highly productive (Alongi, 1998). Approximately 40% of mangrove

production is accounted for by litterfall (Alongi, 1998). Litterfall estimated to be 200

400 gCm-2y-1 and mangles are likely to be an important source of organic carbon,

dependent on the amount exported from the mangrove system (Mann, 2000).

Few studies have investigated the export of nutrients, or outwelling , from

mangles (Alongi, 1998). Outwelling from mangles will depend on the elevation of

the forest and the distance from the coast, with whole forest estimates suggesting that

about 50% of net carbon fixed, or an average of 210 gCm-2y-1 , may be exported as

leaves and twigs (Alongi, 1998; Mann, 2000). Carbon stable isotope signatures have

been used to demonstrate the importance of mangrove detritus to nearshore food webs

(see Mann, 2000). As mangroves withdraw a large proportion of nitrogen from their

leaves prior to senescence, the export of nitrogen to the nearshore zone is likely to be

considerably less than that of carbon (Mann, 2000).

The production by other autotrophic components of the mangrove ecosystem

is often overlooked. Macroalgae, benthic microalgae, phytoplankton, epiphytes and

neuston may account for more than half of the total net primary production in some

mangrove ecosystems (Alongi, 1998). The amount of production by other autotrophs

will be dependent on how well developed the mangrove canopy is, with light

limitation likely to reduce the importance of other primary producers (Alongi, 1998;

Clarke & Kerrigan, 2000). In less luxuriant systems edaphic algae and epiphyte

production may play a significant role in productivity and providing a major source of


food for consumer organisms (Alongi, 1998). The importance of sedimentary

environments that form part of mangles is discussed further in section 2.1.3 below.

Despite the apparent importance of mangrove ecosystems to humans and

surrounding communities, little consideration is given to conservation of mangles,

particularly in developing countries. It is estimated that more than 50% of the world s

mangroves have been removed and that annual rates of deforestation in the Indo-

Pacific continue at 1% per year (Ronnback, 1999; Mann, 2000).

2.1.2. Coral reefs

Like mangroves, coral reefs depend on warm and shallow water (Mann, 2000).

In addition, their distribution is controlled by ocean circulation patterns which affect

the dispersal of coral planula larvae, sedimentation rates and water quality and clarity

(Smith, 1978; McLaughlin et al., 2003). It has also been suggested that coral growth

is greatly influenced by nutrient upwelling (Andrews & Gentien, 1982) and by the

effect of sea level changes on calcification (Davies et al., 1985). However, the

functioning of coral reefs is the subject of continuing scientific debate.

Coral reefs can be grouped into one of three broad categories: atolls, barrier

reefs or fringing reefs (Nybakken, 2001). Fringing reefs are found growing as a

fringe attached to a land mass (Mann, 2000). Barrier reefs are also related to

coastlines, but appear some distance out to sea, creating a lagoon between reef and

land (Mann, 2000). Atolls are isolated structures surrounded by open water (Mann,

2000).

The formation of the three reef types was first explored by Charles Darwin in

1842 who proposed the subsidence or compensation theory which says that barrier

reefs and atolls are formed by the subsidence of volcanic islands with sinking land

first transforming a fringing reef to a barrier reef and finally to an atoll when land

becomes totally submerged (Mann, 2000; Nybakken, 2001). Subsequent drilling has

confirmed this theory on certain atolls, with drilling revealing dead coral far below the

depth at which coral can grow (Mann, 2000).

An alternative theory proposed by Daly in 1915 was termed the glacial control

theory and suggested that formation of some reefs has resulted from coral growth

keeping pace with sea-level change (Mann, 2000). It is likely that the formation of

many reefs is an interaction of sea-level rise and landmass sinking (Mann, 2000). The

formation of reefs is also a complex interplay between the production of substrate by


coral and coralline algae, processes that physically and biologically break the reef

down and transport and redistribution of sediment (Mann, 2000).

Globally, coral reefs can be divided into two biogeographic regions, the Indo-

Pacific and Caribbean, which have distinct faunal assemblages (Mann, 2000).

Individual reefs can be also be divided into seven zones which vary in their

composition, structure and function: (1) reef slope, (2) reef front, (3) algal ridge, (4)

reef flat, (5) patch reef outcrops or bommies, (6) lagoon and (7) leeward reef (Alongi,

1989; Mann, 2000; Nybakken, 2001). The reef front is the zone of active coral

growth being exposed to maximum wave energy, turbulence and hence nutrient

uptake (see discussion of reef nutrition below) (Mann, 2000).

The high productivity of coral reefs in nutrient-poor tropical waters at first

appears paradoxical and raises the question, how do coral reefs maintain high

productivity in low-nutrient water? Nutrient levels in coral reef waters are typically

low, ranging from 0.1 0.5 m of nitrate, 0.2 0.4 m of ammonium and less than

0.3 m of phosphorous (Ferrier-Pages et al., 2000). Despite this, gross primary

production in coral reefs is high, estimated to be 1500 5000 g Cm-2 year-1 in

comparison to the open tropical ocean where productivity is low at 18 50 g Cm-2

year-1 (Nybakken, 2001). Several studies have investigated nutrient sources for coral

reefs and presented reasons for thriving benthic communities in nutrient poor waters.

These have included: the symbiotic association with photosynthetic dinoflagellates

and efficient nutrient use within the coral animal; tight internal recycling of nutrients

within the reef ecosystem through bacterial populations; advection and efficient

filtration of large volumes of oceanic water; upwelling and endo-upwelling; and

inflows from groundwater and terrestrial runoff. The external origin of many of these

sources attests to the importance of ecosystem linkages between coral reefs and

surrounding habitats as outlined earlier (Alongi, 1998).

One of the main factors explaining the nutrient paradox, allowing corals to

thrive in the absence of abundant nutrient sources, is their symbiotic association with

photosynthetic dinoflagellates. The importance of the symbiotic relationship between

coral and zooxanthellae has been demonstrated in a number of studies, although the

precise relationship is the subject of current debate (Falkowski et al., 1993; Alongi,

1998; Nybakken, 2001). Zooxanthellae have been shown to be an important source of

nutrition to corals, with the importance of photosynthetically derived energy varying


between coral species and even between the same species at differing water depths

and light intensity (Muscatine et al., 1989; Falkowski et al., 1993; Muscatine &

Kaplan, 1994; Nybakken, 2001). Photosynthetically derived carbon is thought to be

particularly influential in controlling calcification rates (Alongi, 1998). It has been

suggested that the low nutrient conditions of coral reef waters is essential for

maintaining the symbiotic relationship, with increases in nutrients leading to a

decreased translocation of carbon to the coral host as zooxanthellae increase their

own growth rates (Falkowski et al., 1993; Dubinsky & Stambler, 1996; Alongi, 1998;

Ferrier-Pages et al., 2000).

A further mechanism proposed to sustain coral reefs in nutrient-poor waters is

advection over the reef and its biofiltration capacity. It has been suggested that the

flow of water over a coral reef, integrated over time, combined with the large biomass

of organisms present to biofilter the water, provides a sufficient source of nutrition by

mass transfer of nutrients from the water column to bacteria and filter feeding

organisms of the reef (Atkinson, 1992; Nybakken, 2001). The capacity of coral

morphology to alter water velocities and enhance this mass-transfer of nutrients has

also been considered (Atkinson et al., 2001; Hearn et al., 2001). Experimental studies

have indicated that corals exposed to different water velocities actually change their

skeleton morphology to minimise boundary-layer thickness and maximise nutrient

availability (Alongi, 1998).

Other nutrient sources for corals have been proposed. For instance, the

organic fraction of sediments has recently been shown to be an important food source

for corals (Rosenfeld et al., 1999) and there is also the potential for nitrogen fixation,

both in adjacent water and within coral reef sediments, to provide a significant source

of nutrients (Owens, 1987; Sammarco et al., 1999; Nybakken, 2001). Stable isotope

analysis by Sammarco et al. (1999) has demonstrated the importance of nitrogen

fixation by algal mats as a source of nutrients to mid-shelf corals on the Great Barrier

Reef.

The same study by Sammarco et al. (1999) supported an alternative

explanation for the persistence of coral reefs on the outer-shelf of the Great Barrier

Reef: the upwelling of nutrient rich water adjacent to the reef. Seasonal upwelling

was also proposed as a solution to the nutrient paradox by Andrews & Gentien

(1982). However such attempts to explain the nutrient paradox of corals by upwelling

may be confounded by: the temperature of coastal upwelling frequently being below


the lethal limit of coral-algal ecosystems; upwelling of nutrients should also be

evident from blooms of both planktonic and benthic algae; and, increased benthic

biomass would lead to decreases in light to zooxanthellae and increases in bioeroders,

resulting in coral mortality (Rougerie et al., 1992).

In response to these problems, Rougerie et al. (1992) have proposed an

alternative to conventional upwelling, considering that upwelling of geothermally

heated, deep, nutrient-rich water through the interstitial water in the reef limestone

could be a significant source of nutrients. Tribble et al. (1994) have argued against

the validity of this geothermal endo-upwelling to explain the nutrient paradox and

suggest that the net productivity of coral reefs is in fact comparable to the surrounding

oligotrophic ocean with high rates of respiration offsetting high photosynthetic

production. They suggest that the high rates of primary productivity are not

paradoxical for two major reasons: reef autotrophs having high C:N:P ratios and

therefore require smaller quantities of nutrients than previously supposed; and the

advection of nutrients over reefs discussed above is sufficient to provide nutrition to

the reef (Tribble et al., 1994).

Independent of anthropogenic activities (considered in section 2.2 below),

coral reefs are subject to a variety of natural disturbances which can shape the

composition of reefs in space and time. Coral reefs constantly undergo recovery and

adaptation to a variety of stresses (Done, 1992; Grigg, 1995; Ninio & Meekan, 2002).

These stresses may include predation, competition, storm damage, exposure at low

tide, temperature changes and diseases and pathogens (Brown & Howard, 1985). The

variety of spatial and temporal scales on which these stress act suggests that corals

challenge the classical notion of stability, with coral species likely to be ever-

changing in space and time (Grigg, 1995; Vernon, 1995). Understanding and

recognising the scale of natural long term fluctuations in reefs is important for

distinguishing and assessing the source and scale of potential anthropogenic impacts

(Brown & Howard, 1985; Grigg, 1995; Ninio & Meekan, 2002).

Anthropogenic impacts are estimated to have damaged 30% of all coral reefs

beyond the point at which they may recover (Dubinsky & Stambler, 1996). Of the

remainder of reefs, 30% are considered seriously threatened and only 40% are stable

and safe largely due to their isolation from human populations (Dubinsky & Stambler,

1996). Rates of declines are expected to accelerate, particularly in conjunction with

global warming, which is alarming given the importance of coral reefs to populations


of developing countries (Richmond, 1993; Dubinsky & Stambler, 1996; McClanahan,

2002).

2.1.3. Soft Bottom and Intertidal Habitats

While the major component of coral reefs and mangrove forests are the corals

and mangroves themselves, both ecosystems have significant sedimentary

environments and are adjacent to intertidal habitats. In some cases the productivity of

these areas may be equal to that of the mangroves or corals themselves.

Soft Bottoms Habitats

Sediments of coral reef systems are largely derived from the erosion of corals

intermixed with other carbonate-producing organisms, tending to be coarse in nature

(Alongi, 1989). Conversely, sediments in mangrove environments tend to be muddy

in nature, derived from the deposition and decomposition of organic matter and input

of terrigenous material from rivers (Nybakken, 2001). A wide variety of microbes,

meiofauna and macrobenthos are associated with these habitats and may be important

components of tropical ecosystems (see Alongi, 1989, 1990).

Unconsolidated carbonate sediments, although apparently barren, are

acknowledged to be biologically active components of coral reef systems (Kinsey,

1977; Roelfsema et al., 2002). Only half the area of coral reefs is actually coral, the

other half being composed of sandy substrates (Rasheed et al., 2002). These sands

are very porous, with approximately 50% pore water by volume. This pore water has

elevated nutrient levels relative to the overlying water and may act as a sink of

organic material buffering the reef system from nutrient fluctuations (Rasheed et al.,

2002). Rasheed et al. (2002) suggest that organic matter filtered from the water

column into permeable carbonate sediments is decomposed in the sedimentary

microbial food chain. The nutrients produced by this mineralization are then released

into the pore water and overlying water column where it is available for uptake. This

is one of the processes that may contribute to an explanation of the nutrition of coral

reefs (whether paradoxical or not (see Tribble et al., 1994)) discussed above.

Estimates in one region suggest that benthic microalgae alone constitute up to 20% of

the total benthic chlorophyll a and thus contribute significantly to total reef

productivity (Roelfsema et al., 2002).


In mangals, a similar importance of the microbial food chain in sediments has

been suggested. Since mangroves themselves are not heavily grazed, when they die

their biomass is incorporated into decomposer food chains, highlighting the

importance of sedimentary environments to the function of mangles (Alongi, 1998).

Intertidal Habitats

Intertidal habitats are an important component of coastal tropical ecosystems,

particularly as they form a link between the terrestrial and marine realm. They are

easily accessible for both marine and terrestrial species and provide resources for

human populations. The type of intertidal habitat can vary from soft sediment

habitats to rocky shores, and from small zones to extensive intertidal flats dependent

on the level of tidal fluctuation. The biota of intertidal habitats will be shaped by a

variety of processes. The composition of the community is first and foremost

dependent on the supply of recruits with subsequent growth and survival subject to a

variety physical and biological controls.

The majority of benthic marine invertebrates which contribute to intertidal

assemblages include a planktonic larval phase in their life cycle and the initial

development of communities of these organisms will be largely determined by

processes which affect the recruitment of larvae to benthic habitats (Pawlik, 1992;

Eckman, 1996; Underwood & Keough, 2001). The importance of the supply of larvae

to community ecology has only been recognised relatively recently, leading to use of

the term supply-side ecology (Lewin, 1986). The supply of larvae, and hence the

potential for recruitment to the intertidal, will be driven by a variety of factors,

including: production of larvae by adults, which includes rates of fertilization; the

survival of larvae in the pelagic environment, which will be influenced by physical

conditions, larval behaviour, nutrition and predation; and the influence of local

oceanography on the dispersal of larvae to intertidal habitats suitable for recruitment

(Underwood & Keough, 2001). A number of these factors are likely to be strongly

seasonal and the supply of larvae will be temporally and spatially variable and species

dependent (Hutchinson & Williams, 2001; Sousa, 2001).

Having successfully recruited to the intertidal, a variety of physical and

biological controls will determine the distribution and survival of species within the

intertidal zone. These controls will tend to vary spatially, temporally and with height

on the shore and hence exposure at low tide, leading to the common observation of


spatial patchiness and zonation in species across the intertidal (e.g. Paine, 1966;

Dayton, 1971; Connell, 1972; Peterson, 1991; Schoch & Dethier, 1996; Menge &

Branch, 2001, and many others). The intertidal environment is a zone of high

physical stress for organisms and variations in aerial exposure with each tidal cycle

and exposure to wave energy will determine species composition based on

adaptations to physical conditions. Typically, species best adapted to tolerate exposed

condition are found high on the shore, and those least tolerant low on the shore.

Along with physical tolerances, the distribution of a species in the intertidal

will also be determined by a variety of biological factors. In particular, competition

and predation will change as species composition changes through the intertidal. In

the rocky intertidal, space is often a limiting resource and competition for space will

play a large role in shaping the community (Dayton, 1971; Underwood & Keough,

2001). Species better able to compete for and hold space will tend to become

dominate. Conversely, soft sediment intertidal habitats are rarely space limited

(Peterson, 1991). Predation will also influence species composition, with certain

species more or less susceptible to predation at certain levels on the shore as both

physical exposure and the identity of predators changes (e.g. Paine, 1966).

Substrate type and complexity will also play an important role in shaping

intertidal assemblages (Hutchinson & Williams, 2001). This is particularly so when

the habitat complexity provides species with a refuge, such as from physical stress or

predation, at low tide. For instance, in the rocky intertidal highest densities of small

animals are typically found on macroalgae, as the algae provide the epifauna with a

range of resources, such as food and a refuge from predation and desiccation (Brown

& Taylor, 1999).

2.2. Development and Marine Environmental Impacts



1989; Gerges, 1994; Christie & White, 1997; Hinrichsen, 1998; Thia-Eng, 1999;

Burgess, 2000; Bellan & Bellan-Santini, 2001; de Jonge et al., 2002; Tran et al.,

2002; Li & Daler, 2004). Coastal marine environments and resources are particularly

susceptible to the impacts of development being closest to concentrations of

population and industry, being areas popular for recreation and having a wealth of

exploitable resources (Alongi, 1989; Gerges, 1994; Christie & White, 1997; Bellan &


Bellan-Santini, 2001). With the world s biodiversity centred in the tropics, where

human-induced impacts have already affected about one third of the world s coral

reefs and up to 50% of the world s mangrove systems, the threat to biodiversity from

unplanned development is significant (Thia-Eng, 1999; Mann, 2000).

As populations continue to grow in coastal communities of developing nations,

increased pollution and depletion of resources is highly likely in the absence of

informed management of development (Gerges, 1994; Christie & White, 1997; Thia-

Eng, 1999; Tran et al., 2002). Many developing countries operate on the premise of

development first, mitigation and treatment later , partly as a result of development

priority and lack of financial resources (Thia-Eng, 1999). Given that impacts on the

marine environment are likely to have follow on effects on fisheries and aquaculture

production, food security, employment opportunity and rural stability, it is in the best

interest of developing nations to take a proactive approach to assessing and managing

marine environmental impacts even if from a purely pragmatic perspective (Thia-Eng,

1999).

The variety of anthropogenic activities associated with development that have

the potential to impact the tropical marine environment are not restricted to those

occurring in, or even directly adjacent to, the marine realm. Activities such as land-

use changes resulting in changes in freshwater, nutrient and sediments inputs into the

coastal zone; physical alteration such as the constructions of marinas; aquaculture,

fishing and harvesting of biota; shipping such as physical damage and pest

introduction; oil and gas exploration; and tourism are all recognised to have the

potential to impact water and sediment quality, habitats and marine biodiversity in

tropical marine environments (Morrison & Delaney, 1996).

2.2.1. Land-based activities

Like most nearshore zones, the main impacts on the nearshore tropical marine

environment emanate from land-based activities (Thia-Eng, 1999). It is estimated that

80% of ocean pollutants are from land-based sources (Li & Daler, 2004). The most

significant land-based activities likely to have effects are those resulting in altered

nutrient and sediment inputs to the ocean via rivers and groundwater flows (Morrison

& Delaney, 1996). Disposal of wastes (domestic and non-domestic), application of

fertilisers and clearing of vegetation all have the potential to result in a variety of

impacts on tropical marine ecosystems. Being adapted to clear waters with low


nutrients, coral reefs are particularly susceptible to changes in nutrient and sediment

regimes and are known to be sensitive indicators of environmental pollution resulting

from land-based sources (Brown & Howard, 1985).

Effects of Altered Nutrient Input

One of the most pronounced effects of nutrient addition to the marine

environment is that of eutrophication. Marine eutrophication is generally considered

to be a direct result of increasing population densities and fertiliser use and can be

greatly enhanced by development in adjacent terrestrial areas (Grall & Chauvaud,

2002). Development resulting in increased nutrient loadings to coastal waters has the

capacity to have a variety of general effects on the environment. For instance

increased nutrients can stimulate higher primary production and directly or indirectly

advantage consumer organisms (Grall & Chauvaud, 2002). Alternatively, increased

sedimentation of organic matter driven by enhanced water column productivity may

be harmful to some organisms through saltation, habitat modification and oxygen

depletion (Grall & Chauvaud, 2002).

More specifically to tropical environments, the adverse effects of nutrient

enrichment on coral reefs have been determined through both laboratory experiments

and in situ observations (Ferrier-Pages et al., 2000). As outlined above, coral

ecosystems are a balance of processes allowing organisms to function in nutrient-poor

environments. Hence, anthropogenic elevation of nutrients may alter this balance and

affect the reef ecosystem in a variety of ways.

Firstly, nutrient enrichment may enhance algal growth, with the proliferation

of macroalgae leading to a competition for space with corals and potentially a

decrease in coral recruitment and a shift in dominance towards macroalgae (Dubinsky

& Stambler, 1996; Wilkinson, 1996; Ferrier-Pages et al., 2000; Knowlton & Jackson,

2001). Increased nutrient (and sediment) levels resulting from land-based activities

can lower the threshold for macroalgal dominance over corals (Knowlton & Jackson,

2001). In addition increased algal cover in the water column and on the reef reduces

light available to coral, giving further advantage to macroalgae (Dubinsky & Stambler,

1996; Wilkinson, 1996; Ferrier-Pages et al., 2000).

At a cellular level, the functioning of the coral-zooxanthellae symbiosis may

be disrupted. Increased nutrients (in the form of nitrogen) have been shown to

increase the density of zooxanthellae and chlorophyll a in host coral (Falkowski et al.,


1993; Dubinsky & Stambler, 1996; Ferrier-Pages et al., 2000). The resulting carbon

limitation leads to a decrease in photosynthetic rate per algal cell and carbon is

respired instead of being translocated to the host coral (Falkowski et al., 1993;

Dubinsky & Stambler, 1996; Ferrier-Pages et al., 2000). Hence, even if not directly

excluded by water column or benthic algae, nutrient enrichment will lead to stress in

corals and leave them more susceptible to other natural and anthropogenic

disturbances.

Effects of Altered Sediment Input

Increased sediment inputs from land-based sources have also been

documented to have significant impacts on coral reef and other marine ecosystems

(Brown & Howard, 1985; Wilkinson, 1996; Nemeth & Nowlis, 2001; Gillanders &

Kingsford, 2002; Golbuu et al., 2003; McLaughlin et al., 2003; Pulfrich et al., 2003).

Increased sediment supply to the ocean is particularly prevalent in the wet tropics,

where high relief and natural runoff combine with poor land-use practices, rapid

deforestation (Milliman et al., 1999; Golbuu et al., 2003) and, in some regions,

mining activity (Barnes & Lough, 1999; Pulfrich et al., 2003; Walling & Fang, 2003).

For example, a four-fold increase in sediment delivery to the Great Barrier Reef has

been observed in response to land-use intensification (Neil et al., 2002). In

catchments in southeast Asia, land-use intensification has driven an order of

magnitude increase in sediment loads (Walling & Fang, 2003). Walling & Fang

(2003) present examples of very large increases in sediment flux in some major rivers,

including a 75% increase in the Hongshuihe River in China and 80% in the Yazuglem

River in Kazahkstan over the period for which records exist.

Increased sedimentation can impact coral reefs through a variety of physical

and biological processes (Richmond, 1993; Dubinsky & Stambler, 1996; Golbuu et al.,

2003). Physical processes include increased light attenuation due to higher turbidity,

direct smothering of coral organisms (Brown & Howard, 1985; Richmond, 1993;

Dubinsky & Stambler, 1996) and enhanced transport of other pollutants bound to

sediments (Gillanders & Kingsford, 2002; Neil et al., 2002). This ability to transport

pollutants means that even small increases in sediment supply may have considerable

ecological consequences through effects on coral biology (Neil et al., 2002).

Effects on the biology of the coral from sedimentation will be highly species-

specific (Brown & Howard, 1985; Torres et al., 2001). Decreased photosynthetic,


calcification and nutrient uptake rates, expulsion of zooxanthellae, increased

pathology and increased mucus production, and reduction in recruitment are observed

to varying degrees in different species, with consequences ranging from minimal to

catastrophic (Brown & Howard, 1985; Richmond, 1993; Nemeth & Nowlis, 2001;

Torres et al., 2001). For instance, mucus production is a means to slough off

deposited sediments, but may result in loss of up to 40% of fixed carbon in some

species of coral, leading to considerable energy loss and stress (Brown & Howard,

1985; Barnes & Lough, 1999). Stress is also induced through loss of energy from

expelled symbionts and reduced ability to feed as sediments are removed, but again

these responses will be species dependent (Barnes & Lough, 1999; Nemeth & Nowlis,

2001).

Despite the variety of possible effects, coral may be resilient to surprising

levels of anthropogenically enhanced sedimentation. For instance, no impact from

mining on coral of the genus Porites was found in Papua New Guinea, despite

average sedimentation rates up to 156 mg.cm-2d-1 over a 3 year period (see Barnes &

Lough, 1999). These results may be due to the species-specific response of Porites,

or due to a variety of other factors that influence the impact of increased

sedimentation.

A study by Golbuu et al. (2003) is a good example of the interplay of the

variety of factors that may determine the influence of increased sedimentation on the

marine environment. The authors investigated sedimentation of terrigenous muds

driven by extensive land clearing for agriculture in Arai Bay in Palau, Micronesia.

They found corresponding impacts on coral reefs in the bay, with follow-on socio-

economic impacts as fisheries collapsed. For instance, sedimentation has resulted in

proliferation of algal mats, which trap further sediments. Resuspension of sediments

with each tide means that corals are stressed both due to smothering and increased

turbidity, resulting in reduced light availability. The impact of sedimentation is also

exacerbated in the region by clearing of mangroves, which have the capacity to trap

15-30% of fine sediments entering the bay. The limited flushing of the bay also

means that there is continuous accumulation of sediments.

The above study demonstrates that the influence of both nutrient and sediment

addition to the nearshore zone will be partially determined by the residence time and

flushing rates of the receiving waterbody (Grall & Chauvaud, 2002). Shallow

waterbodies with long residence times are more susceptible to the effects of nutrient


enrichment and sedimentation than areas with deep water and strong flushing (Grall &

Chauvaud, 2002). Whether sediment is delivered to the substratum or simply

advected through the system is an important determinant of the effects on coral reefs

(Torres et al., 2001).

Effects of Altered Freshwater Input

Land-based activities that alter the flow of freshwater to the marine

environment may also result in ecological impacts. Independent of alteration of

nutrients and sediments in freshwater inputs to the coastal environment discussed

above, anthropogenic activities may also result in diversions and reductions in

freshwater flow and alterations of timing and rates of flow to coastal systems

(Gillanders & Kingsford, 2002). As well as altering the salinity of receiving waters

and supply of sediments and nutrients, changing freshwater flows can result in

changes in temperature and alter the extent of freshwater plumes (Gillanders &

Kingsford, 2002). Subsequent effects on organisms can include mortality, changes in

growth and development and in some cases movement of organisms (Dubinsky &

Stambler, 1996; Gillanders & Kingsford, 2002).

In the Arai Bay study by Golbuu et al. (2003) the impact of increased

freshwater on coral reefs was found to be minimal as freshwater outflows was

confined to the surface layer, only interacting with corals at extreme low tide. Despite

the likely confinement of freshwater to the upper layer, Gillanders and Kingsford

(2002) provide a number of examples of impacts of altered freshwater input on corals.

The authors also document potential impacts on mangals. Mangroves are unable to

avoid freshwater flows, and land-based activities can both enhance and divert

freshwater from mangals (Ellison & Farnsworth, 2001). Increased freshwater flow

can prevent upstream movement and retention of mangrove propagules, preventing

re-seeding of the mangrove forest (Gillanders & Kingsford, 2002). Given their

adaptation and zonation to specific salinities, mangroves will be impacted by changes

in freshwater, with competitive exclusion of certain species from certain areas of the

shore foreseeable as salinities change (e.g. Gillanders & Kingsford, 2002).

2.2.2. Physical alteration

As for land-based activities, physical alteration of the marine environment will

largely occur in the coastal zone. This means that mangrove ecosystems which


dominate the tropical nearshore zone are particularly susceptible to this type of

development. As an example, in Indonesia, which has the largest area of mangroves

of any country in the world, development of agriculture and aquaculture has seen the

loss of 40% of mangroves through physical removal (Morrison & Delaney, 1996). In

the Philippines and Ecuador 50% of mangroves have been converted to shrimp ponds

in the last 30 years (Ellison & Farnsworth, 2001). The particular importance of

nearshore habitats, providing a buffer between land-based activities and the marine

environment (e.g. Golbuu et al., 2003), means that physical alteration threatens

coastal habitats that are of vital importance to marine ecosystem health and

biodiversity (Thia-Eng, 1999).

2.2.3. Fishing

The impact of fishing activities on the marine environment is likely to be most

difficult to address in developing nations where many people living below the poverty

line and depend on fishing as a means of subsistence (Richmond, 1993; Dayton, 1995;

Wilkinson, 1996; DeVantier et al., 2004). Financial needs and declining catch rates

also mean that little consideration will be given to the marine environment in the face

of potential profits from harmful fishing practices (Wilkinson, 1996). In particular,

the demand for live fish in developed nations such as Singapore, Taiwan, China and

Hong Kong encourages fisherman in developing nations to catch as many fish as they

can, as fast as they can (Dayton, 1995; DeVantier et al., 2004). Fish targeted for the

live trade are disappearing from reefs in the Philippines and are expected to be in a

similarly depleted state in Indonesian waters within five years (Dayton, 1995). Of

further concern, the use of harmful fishing practices are often the best means of catch

large numbers of fish rapidly. These include blast fishing and, increasingly due to its

potential for more covert application, the use of cyanide (Dayton, 1995; Wilkinson,

1996; DeVantier et al., 2004).

Divers use bottles of sodium cyanide squirted into holes in coral reefs to stun

fish, which are then taken to holding pens to recover for the live fish market (Dayton,

1995). While the large fish targeted by fishermen are able to survive the doses of

cyanide, other species such as invertebrates and small fish are not (Dayton, 1995;

Wilkinson, 1996). The destruction of biodiversity by cyanide fishing also extends to

the corals themselves, with dosages applied at hundreds of times that lethal to coral

(Dayton, 1995; Wilkinson, 1996). The Indonesian region is one of a number in South


East Asia where the use of cyanide in the capture of live reef food fish is becoming

more prevalent (Morrison & Delaney, 1996; DeVantier et al., 2004).

Overfishing is also a concern in the tropical marine environment, but is harder

to address than elsewhere as populations in the topics often depend on fishing for

subsistence (but see de Boer et al., 2001). Examples of the ecological effects of

overfishing on coral reef communities abound (e.g. see Wilkinson, 1996; McManus et

al., 2000; Knowlton & Jackson, 2001). For instance, in developing nations intense

subsistence over-fishing can greatly reduced herbivorous fish abundance, leading to

enormous increases in macroalgal cover which progressively overgrows coral

(McManus et al., 2000; Knowlton & Jackson, 2001). Dominance shifts from

palatable to unpalatable macroalgae as a result of over-fishing of herbivorous fish are

expected to occur in the Philippines and Indonesia, and may persist even if herbivore

populations subsequently recover (Knowlton & Jackson, 2001).

Countries without the financial means to control fishing activities are

particularly susceptible to damaging fishing practices and will depend on an united

international approach to ensure the sustainability of fishing in regions were people

rely on fishing for their livelihoods (Dayton, 1995). As long as demand exists for

certain types of vulnerable fish, people in developing nations will continue to harvest

them by whatever means available to them.

2.2.4. Oil and gas exploration and production

Oil and gas exploration tends to occur in more offshore areas and not in the

coastal zone, however impacts on the coastal marine environment may result from

both onshore and offshore oil and gas developments. For instance transport of

contaminants, such as drill cuttings, drilling muds and produced formation water, has

the potential to impact environments linked by regional oceanography (or terrestrial

water flows) to exploration areas (Lavering, 1993). The shipping and transport of oil

and gas also has the potential to impact the marine environment as a result of oil spills

(Morrison & Delaney, 1996). For instance, oil spills have impacted mangals

dramatically in the Caribbean and have the potential to do so elsewhere where tanker

traffic is significant (Ellison & Farnsworth, 2001).

In the Timor Sea the distance of production activities from the coast and the

nature of volatile-rich indigenous crudes suggests that impact from an acute oil spill

on coastal marine environments is unlikely, with oil likely to undergo rapid


evaporation of most components within 72 hours of release (Lavering, 1993). Only

chronically persistent oil releases, combined with conditions of low temperature, wind

and wave energy, are thought likely to result in ecological disturbance in the region

(Lavering, 1993).

2.2.5. Tourism

Tourism has the potential to benefit local communities in developing nations

by providing a source of income, holding back industrial development and aiding in

protection of the natural environment through giving it an economic value (Hawkins

& Roberts, 1994; Rinkevich, 1995; Epstein et al., 1999; Bellan & Bellan-Santini,

2001; Carter, 2001; Gossling, 2001). In the past tourism has been considered a low

impact alternative to extractive uses of the marine environment (Zakai & Chadwick-

Furman, 2002). However, the potential also exists for significant environmental

impacts from tourism development, particularly as tourist numbers in needy

developing nations continue to grow, often at a rate too fast for effective management

(see Hawkins & Roberts, 1994; Carter, 2001; Gossling, 2001).

Many of the impacts of tourism development are considered as part of the

discussion above: developments to accommodate increased tourism have the potential

to increase inputs of nutrients and sediments to the marine region, and to drive

physical alteration of habitats and increase shipping activity. For instance increased

urbanisation driven by tourism development in the Yuctan Peninsular of Mexico has

caused increased pollution of the nearshore zone (Tran et al., 2002). Similarly in the

Red Sea, physical alteration, sediment from construction, sewage disposal,

desalination, irrigation and rubbish driven by tourism developments threaten coral

reefs in the region, which ironically are the basis of the tourism industry and urban

expansion (Hawkins & Roberts, 1994). Encouraging tourism is also known to impact

mangals as tourism often involves conversion of some of the mangal to visitor

facilities, for instance boardwalks designed to protect mangroves themselves alter the

benthic community of the mangrove ecosystem (Ellison & Farnsworth, 2001).

Impacts specific to tourism development are largely related to the direct and

indirect impacts of increased numbers of innocent visitors utilising the marine

environment (Rinkevich, 1995). For instance, increases in SCUBA diver numbers

have well documented impacts on coral reefs including decreases in coral cover,

richness and diversity (Rinkevich, 1995). Hawkins and Roberts (1994) describe how


increased tourism in the Red Sea has degraded coral reefs to such an extent in the

nearshore region that the area is now of little interest to divers and snorkellers .

Consequently more offshore regions now support the diving industry and are subject

to a magnification of associated impacts (Hawkins & Roberts, 1994).

Direct Impacts of Tourism

Direct damage is caused to corals by: mechanical damage through tourists

kicking, trampling and holding onto corals; abrasion of coral tissue; and by re-

suspension of sediments and subsequent burial of coral (Keough & Quinn, 1991;

Hawkins & Roberts, 1994; Rinkevich, 1995; Brown & Taylor, 1999; Epstein et al.,

1999; Zakai & Chadwick-Furman, 2002). Indirect damage may also result from

misplaced boat anchors (Hawkins & Roberts, 1994). Once damaged through these

means, corals are more susceptible to disease and algal competitors and less likely to

recover from other stresses, particularly as survivorship, reproductive activities and

substrate for planulae larvae settlement are reduced (Brown & Howard, 1985;

Hawkins & Roberts, 1994; Rinkevich, 1995; Zakai & Chadwick-Furman, 2002).

A number of studies have documented the direct impact of diving on reefs.

Around Egypt there has been shown to be significantly more broken coral, fragments

of coral reattached to the reef and partially abraded and dead coral in areas heavily

used by divers, compared to control sites. A study by Epstein et al. (1999), also on

Red Sea coral reefs, found that small-scale coral reef closure had a number of benefits

to coral as a result of excluding tourists. These include: a three-fold increase in live

coral cover; increases in medium and large colonies; and significantly fewer broken

and partially dead corals. In the same region, a 19-year study demonstrated a two-

order magnitude reduction in a species of branching coral particularly susceptible to

mechanical damage by diving tourists (Epstein et al., 1999).

It has been suggested that while the direct impacts of tourist diving on corals

rapidly accumulates, once a certain level of use is reached, the impact appears to

stabilise (Hawkins & Roberts, 1994). This may be related to the resilience of coral

reefs to natural disturbance events as discussed above (section 2.1.2) and in Vernon

(1995). The point at which recreational activities causes significant alteration may

differ between locations, dependent on the presence of vulnerable reef organisms such

as branching coral, the awareness and training of divers, and level of other

anthropogenic impacts (Rinkevich, 1995; Zakai & Chadwick-Furman, 2002). The


topography of a reef site may also determine its susceptibility to damage, independent

of the level of diving pressure (Rouphael & Inglis, 1997). This suggests that the

carrying capacity for ecologically sustainable tourist diving will need to be determine

on a reef by reef basis (e.g. Hawkins & Roberts, 1994; Rouphael & Inglis, 1997;

Zakai & Chadwick-Furman, 2002).

Indirect Impacts of Tourism

Interestingly, tourism can also be related to impacts on local fisheries, both

indirectly and directly. Hawkins and Roberts (1994) suggest that large-scale tourism

developments in the Red Sea have driven a large demand for seafood, leading to

overfishing of lobster and large reef-fish stocks to supply the tourist market. The

marine-curio trade has also been documented to have ecological effects as specific

key species are harvested by tourists and tourism operators alike for souvenirs

(Hawkins & Roberts, 1994). For instance, harvesting of pufferfish and triggerfish on

Egypt s Red Sea reefs has led to reduced predation on sea urchins and explosions in

their populations (Hawkins & Roberts, 1994). This in turn has resulted in extensive

reef erosion by the urchins whilst feeding on filamentous algae.

Mitigation of Tourism Impacts

While development of tourism is recognised as essential to the economies of

coastal developing nations throughout the world, there is a clearly demonstrated

impact of poorly planned tourism development on the marine environment, and

perhaps on the ability of these environments to continue to attract the tourist dollar

(e.g. Hawkins & Roberts, 1994; Brown & Taylor, 1999; Epstein et al., 1999). Many

authors stress that planning for increased tourism numbers is the key to mitigating the

potential impacts on the marine environment. In an attempt to assist planning for the

impact of tourist diving, Rouphael and Inglis (1997) examined how the training level

of divers and the characteristics of the dive site influence how susceptible a site is to

damage. Their results suggest that controlling impacts will not be achieved by

limiting diver numbers alone, but will depend on taking preventative measures such

as educating divers pre-dive about how to avoid damage to corals and excluding

trainee divers from vulnerable sites (see also Zakai & Chadwick-Furman, 2002).

In the face of economic necessity for increased tourism on coral reefs and the

apparent inevitability of damage suggested by Rouphael and Inglis (1997), Rinkevich


(1995) presents the novel approach of re-seeding reefs damaged by tourism with

sexual and asexual coral recruits. While this approach may be beneficial in areas

already degraded by tourism, it should not be used as an excuse to delay adequate

protection of the marine environment until after impacts from substantial tourism

development have occurred. Furthermore such approaches are likely to be ineffective

if impacts from high tourist numbers continue to occur (Rodgers & Cox, 2003).

Regulation and enforcement of tourism activities should be the basis for protecting the

marine environment from tourism developments rather than rehabilitation projects

(Hawkins & Roberts, 1994; Rinkevich, 1995).

2.2.6. Shipping activities

Many of the other aspects of development discussed above have the potential

to lead to increased shipping, including fishing, oil & gas exploration and tourism.

Increased shipping in conjunction with the above activities can have a number of

general impacts on the marine environment. For instance, increased shipping is likely

to necessitate the development of infrastructure to accommodate vessels, such as

marinas, with the same impacts as physical alteration. All types of shipping and

fishing vessels can cause pollution through accidental and deliberate discharge of

waste and dirty oil products (Morrison & Delaney, 1996). Increased vessel visitation

to coral reefs to cater for tourism is likely to result in physical damage (e.g. Hawkins

& Roberts, 1994).

Worldwide, shipping activity has also been directly related to the risk of

introduction of non-indigenous species (Carlton, 1987; Carlton, 1989; Carlton &

Geller, 1993; Carlton, 1996; Lavoie et al., 1999). Even small recreational craft which

lack ballast water have the potential to introduce species via hull fouling (Coutts,

1999; Wyatt et al., in press). While the impact of temperate marine invasions is being

better studied, there is also the potential for introductions via shipping to have

deleterious consequences on marine biodiversity in the tropics (Eldredge & Carlton,

2002; Hewitt, 2002; Paulay et al., 2002).

2.3. Baseline Survey Techniques For Developing Nations

Baseline data and ongoing monitoring is recognised as essential for assessing

impacts of human activities on the marine environment (Alongi, 1989; Gerges, 1994).

Developing nations in particular require techniques that are repeatable, rapid and cost


effective (Gerges, 1994). These techniques also need to be simple enough to be

carried out with minimal training. There has been a rapid evolution of technology and

methods available for assessment and management of marine environments such as

remote sensing, geographic information systems (GIS), and photographic and

videographic survey methods.

Remote sensing and aerial photography is particularly useful as it allows large

areas to be investigated with minimal effort (Roelfsema et al., 2002). This can be

particularly useful for studying anthropogenic impacts which may occur over large

spatial scales. Remotely sensed data has been used in tropical marine environments to

determine: sediment production by benthic microalgae in coral reefs (Roelfsema et al.,

2002), and to map coral reef bathymetry and coral cover (Mumby et al., 1998;

Mumby et al., 2001; Isoun et al., 2003).

Remotely sensed data can also be used as a means to focus more intensive

investigation, thereby minimising wasted resources. For instance, Torres et al. s

(2001) study investigating the influence of sedimentation on coral reefs in the

Dominican Republic was dependent on a baseline, rapid ecological assessment which

used remotely sensed data in the form of satellite and aerial photograph images to

focus further surveying work. In the Timor Sea, where little baseline information on

biodiversity and coastal habitats is available, the need to use aerial surveillance has

been recognised due to a lack of extensive resources for other more intensive forms of

marine monitoring (Morrison & Delaney, 1996).

Broadscale remote sensing techniques may give information on habitats or

species coverage, but not species or health information (Riegl et al., 2001). This

information is generally essential for assessing impacts and smaller-scale survey

techniques are required. Videographic and photographic surveys are developing as

particularly promising means to rapidly assess marine ecosystems and detect impacts

on a small scale, most notably in studies of coral reef ecosystems. A number of

attempts have been made to optimise such rapid assessment techniques, often for

application in developing nations (e.g. Sullivan & Chiappone, 1993; Mumby et al.,

1999; Edinger & Risk, 2000; Riegl et al., 2001; Samways & Hatton, 2001; Kvernevik

et al., 2002).

Prior to the development of relatively cheap and reliable underwater camera

equipment (Jaap & McField, 2001), assessment of coral reefs was undertaken by

techniques that have considerable draw backs. Direct assessment techniques most


commonly employ line intercept transects (e.g. English et al., 1994) or quadrat

analysis. These techniques require considerable time in the field and hence expense,

as well as significant skills required to take notes underwater (Segal & Castro, 2001).

A further problem is that of parallax, with the complex topography of coral reefs

making sampling by applying a flat line or quadrat problematic (Segal & Castro,

2001). The line intercept transect also has drawbacks when it comes to assessing

biodiversity parameters (see Edinger & Risk, 2000).

There are a number of advantages of video and photo surveys over

conventional techniques. Importantly for developing nations, the techniques allow

rapid and repeatable measures that can be applied to large areas with relatively low

cost and minimal training (Carleton & Done, 1995). The data obtained provides a

permanent record, allowing for multiple analyses including temporal analysis of

community change (Carleton & Done, 1995).

Potential disadvantages of videographic and photographic techniques

compared to conventional analyses conducted in the field largely related to reduced

taxonomic resolution, particularly in regions with limited water clarity or for cryptic

taxa (Carleton & Done, 1995; Segal & Castro, 2001). Edmunds et al. (1998) found

that photographic analysis of juvenile coral density did not correlate with visual field

observations and concluded that photographic surveys were an unsuitable technique

for assessing cryptic species or juveniles that utilise microhabitats and hence are

likely to be undetectable in photographs (see also Foster et al., 1991). Brown and

Howard (1985) use apparent differences in the tolerances of branching and massive

species of coral to highlight the need for sensitivity analysis of survey techniques. As

for remote surveys, videographic and photographic survey techniques should always

be ground-truthed to determine their efficiency at sampling the unit of study

(Edmunds et al., 1998).

Once suitable survey techniques have been identified, periodic monitoring and

comparison to baseline data can be used to detect the impacts of development on the

marine environment (Thia-Eng, 1999). Assessing change is dependent on regular

monitoring by standard repeatable methods, particularly as this allows for separation

of natural fluctuations and anthropogenically induced change (Brown & Howard,

1985; Sullivan & Chiappone, 1993).

There are two types of impacts from development that require different

monitoring strategies (Warnken & Buckley, 2000). Point source discharges of


pollutants that are naturally absent or in very low concentrations in the region of

interest will generally not require baseline sampling prior to impacts. On the other

hand, monitoring and assessment of anthropogenically induced changes in factors that

are subject to significant natural fluctuations will often be dependent on baseline data

obtained prior to the onset of anthropogenic influence on the parameter (Warnken &

Buckley, 2000).

Warnken and Buckley (2000) have proposed a criteria for assessing the

scientific quality of monitoring programs in terms of precisely and reliably

documenting the impacts of developments, including:

1. the monitoring programme needs to discriminate between construction and

operational phases of the development;

2. baseline monitoring should be conducted prior to development, giving

particular consideration to the length and periodicity of sampling;

3. seasonal variations should be monitored, both during baseline and operational

monitoring;

4. spatial design of the monitoring program should incorporate control as well as

impact sites;

5. measurements and/or samples should be replicated, for each parameter at each

site;

6. results from predevelopment baseline monitoring should be subject to a priori

power analysis; and

7. results from operational monitoring should be subject to a posteriori power

analysis.

The authors propose that the these criteria will be most readily met by a

BACIP (before-after, control-impacted paired) monitoring program. The statistical

power of the monitoring program is essential (criteria 6 & 7). The statistical ability to

detect natural and anthropogenic change should be investigated before and after

monitoring occurs (Warnken & Buckley, 2000). Given adequate statistical power,

there is the potential for monitoring to detect environmental impacts even before they

become visually evident. In a similar vein, implementation of monitoring programs in

developing countries have demonstrated that environmental changes could be

detected soon enough for management interventions to take place (Thia-Eng, 1999).

Many monitoring programs begin after development, and hence lack the B

in BACIP. The importance of before-impact baseline information is demonstrated in


the study of coral reef ecology (see Knowlton & Jackson, 2001). There was a

common belief until the 1980s that coral reefs being studied were pristine, however

paeloecological data suggest anthropogenic impacts on reefs began much earlier than

the first ecological surveys (Knowlton & Jackson, 2001). As another example, the

need to identify and measure the initial conditions of benthic communities is also

considered essential as the species-specific consequences of eutrophication are hard to

predict without prior information (Grall & Chauvaud, 2002).

In the absence of the BACIP monitoring design, retrospective analyses can be

performed to account for the before-development condition. For instance annual

density banding in massive corals indicating growth and calcification rates provide a

means to retrospectively monitor environmental conditions in reef waters (see Barnes

& Lough, 1997; Barnes & Lough, 1999).


3. Characterisation of Coastal Sediments: Origin and Fate

3.1. Introduction

Globally, East Timor is one of the most significant contributors of sediment to

the ocean (Milliman et al., 1999). Transport of sediments to the ocean via rivers

represents an important process in the global geochemical cycle and is a key

component of the global denudation system (Walling & Fang, 2003). Timor, along

with other islands of the Indonesian region, Sumatra, Java, Borneo, Sulawesi, and

New Guinea contribute 4.2 × 109 tonnes of sediment to the ocean via rivers annually

(Milliman et al., 1999). Despite only representing 2% of land area, these islands

contribute 20 to 25% of global sediment input (Milliman et al., 1999). The magnitude

of fluvial sediment flux has significant implications for the structure, function and

susceptibility of surrounding nearshore coastal marine environments.

Rates of fluvial sediment flux in the region are naturally high as a result of

mountainous terrain, highly erodible strata, and high seasonal rainfall (Milliman et al.,

1999). However, anthropogenic activities such as deforestation, agriculture and

mining greatly enhance sediment flux and are particularly prevalent in the developing

nations of the Indonesian region (Milliman et al., 1999; Walling & Fang, 2003).

Sediment flux to the ocean via rivers is considered an important measure of land

degradation and is one of the major ways in which land-based activities may impact

the nearshore marine environment (Walling & Fang, 2003).

The impact of fluvial sediment flux on the coastal marine environment will be

determined to some extent by the retention and transport of sediments in the nearshore

zone. The fate of sediment leaving islands such as East Timor will be determined by

the presence of estuaries, the width of the continental shelf at the river mouth and

local oceanography (Milliman et al., 1999). The lack of estuaries, along with the

narrow width of the shelf, means that rivers on East Timor s south coast discharge

directly to the ocean and sediments could be expected to be directly transported to the

slope and deeper waters beyond (Milliman et al., 1999).

If retained in the nearshore zone, the likelihood of impacts on biota from

enhanced sedimentation as a result of land degradation has been well established

(Brown & Howard, 1985; Dubinsky & Stambler, 1996; Nemeth & Nowlis, 2001;

Golbuu et al., 2003; Pulfrich et al., 2003). Increased sediment flux can result in

physical impacts such as habitat alteration, direct smothering of organisms and


reduced water clarity (Brown & Howard, 1985; Dubinsky & Stambler, 1996; Golbuu

et al., 2003). Species which rely on water clarity and light for photosynthetically

derived energy, such as corals, macroalgae and seagrasses, are particularly likely to be

affected by increased sediment supply and turbidity in the nearshore zone as light

attention is increased (e.g. Brown & Howard, 1985; Nemeth & Nowlis, 2001; Torres

et al., 2001).

Sediment flux to the nearshore zone can also determine the rate at which

contaminants from land-based sources are delivered to marine ecosystems (Neil et al.,

2002). For instance, sediment-associated transport accounts for more than 90% of the

total river-borne flux of elements such as P, Ni, Mn, Cr, Pb, Fe and Al (Walling &

Fang, 2003). The ability to transport pollutants means that even small increases in

sediment supply may have considerable ecological consequences for the marine

environment (Neil et al., 2002).

The need for knowledge regarding the supply of sediment to the Timor Sea via

rivers in order to assess potential impacts of anthropogenic activities has been

acknowledged (Morrison & Delaney, 1996). In this study, coastal sediments of East

Timor s south coast are documented and described for the first time. Specifically, the

study aimed to: (a) use the relative contributions of terrigenous and biogenic material

in coastal sediments to assess the extent of linkage between land-based sources of

pollution and the marine environment; (b) conduct a preliminary assessment of

nearshore transport mechanisms, and hence the fate of material from land-based

sources in the nearshore zone; and, (c) provide a baseline dataset against which to

assess the impacts of development on the coastal sedimentary environment.

3.2. Materials & Methods

3.2.1. Study Site & Sampling Design

The nearshore coastal zone around Betano on the south coast of East Timor is

characterised by steep, wave-exposed sandy beaches and an extensive wave-cut

intertidal reef platform. The sandy beach environment dominates the coastal zone

west of the village to the mouth of the River Quelan, while to the east the reef

platform extends for approximately 13 km along the coast (Figure 2). The reef

platform is described in more detail in Chapter Four, which is focused on the biota of

the reef. In this phase of the study sediment sampling was undertaken along the sandy

beach, as well as on and adjacent to the reef platform. Beach sediments were sampled


at seven sites along the beach at increasing distances from the river mouth (S1 S7)

(Figure 2). Sediment samples were taken along transects across the reef (T1 and T4,

see chapter four for locations). Samples were also taken at 10, 20 and 30 meters

seaward of the reef platform at T4 (S8 S10). In addition, two sediment cores (C1 &

C2) were taken at the mouth of a seasonal river which crosses the reef platform at T4.

3.2.2. Qualitative Analysis

The sedimentary environment in the region was analysed qualitatively in three

ways. Firstly, observations about the beach environment were made, in particularly

the shape and exposure of the beach were documented. Secondly, a qualitative

assessment of offshore habitats was undertaken through examination of debris

occurring at the high tide mark on the beach above the reef platform. Thirdly, an

assessment of coastal sediment movement was undertaken through examination of

aerial photographs of the region.

3.2.3. Sediment Sampling & Analysis

Sediment samples of similar volume (~500 cm3) were collected from both the

beach, the centre of the reef platform, and adjacent to the reef at low tide. Samples

were returned to Perth for analysis of grain size and composition. Grain size analysis

was conducted on all sediment samples collected. Dry sediment samples were

weighed and mechanically shaken through sieves with 2mm, 1mm, 500 m, 250 m,

125 m and 63 m apertures. The weight of each fraction was analysed using the

method and software of Blott and Pye (2001) and results are reported in terms of the

definitions provided by the authors.

Grain composition analysis was more focused than grain size analysis due to

the considerable time required to conduct grain counts. Grided-slide counts were only

conducted on the 500 m fraction of samples from stations S2, S8, S9 and S10 and the

middle of T4. Preliminary investigations indicated that the 500 m fraction was most

useful for detecting the influence of biogenic sediment production in the vicinity of

the reef. Similarly, sites chosen were those that best displayed the influence of

biogenic production. Qualitative assessment of the composition of beach sediments

(S1 S2) indicated that they were largely identical and S2 was arbitrarily chosen to

represent these sediments. Similarly, there was little variation evident across the reef

and little difference expected between transects on the reef. This, along with the


proximity to the location of core samples and reef-adjacent samples, led to sediments

from the middle of T4 being selected for analysis. All three samples taken adjacent to

the reef (S8 S10) were included in grain composition analysis.

Grain composition analysis consisted of taking each sample selected for

analysis and evenly spreading this on a grided plate. Random sub-sampling was not

considered necessary in this instance as only one size fraction was being analysed,

precluding sorting and biasing of the samples based on grain size. All grains

contained within a single grid square were transferred to a numbered grid slide and

arranged according to grain type. Successively more grid-squares were transferred to

the slide until the desired number of grains had been counted (~100 200).

Two core samples were taken at the mouth of the river by hammering 50mm

PVC piping into the sediments as far as possible, sealing with water and an end-cap

and removing by hand. Core one (C1) was taken behind the beach berm towards the

river approximately 1.15m above mean low water level (MLWL) (Figure 3). Core

two (C2) was taken in front of the beach berm at about 0.7m above MLWL. Both

cores were driven in as far as possible. Following removal of cores, attempts were

made to collect samples of water from the bottom of each core hole to determine if

groundwater seepage was evident. A sample of water seeping from the base of the

beach face over the rock platform at low tide was collected for analysis.

Both cores were transported to Perth where they were cut in half and the entire

length of one half photographed in a number of photographs. Composite images of

each entire core were constructed from these photos using Adobe Photoshop. Both

the photos and cores were then analysed for evidence of bands of material of

terrigenous or biogenic origin.


Figure 2: Location of the seven beach sediment sampling sites (S1 S7) west of Betano. See Chapter Four for locations of reef sampling transects and river at which cores were taken. Sediments analysed

for grain size and composition to determine the relative contributions of terrigenous and biogenic material on both the beach and in the vicinity of the intertidal reef in order to elucidate the influence of

fluvial flux on the nearshore zone.


Figure 3: Schematic representation of locations of cores one (C1) and two (C2) on a typical beach profile above the intertidal reef platform. General beach profiles consisted of a sloping beach face

stretching from the base of the intertidal reef platform at mean low water level (MLWL) to a berm at high water level. Behind the berm the beach sloped downwards into the river mouth. For beaches not

adjacent to the reef or river mouths, the beach slope was more pronounced and there was no slope behind the berm, with vegetation beginning at high water level.

C2

C1

10m

4.5m

8m

0.7m

Reef

MLWL

1.15m

Sand

Berm

River

Ocean


3.3. Results

3.3.1. Qualitative Analysis

Unlike the tidally dominated, low energy, muddy environments of northern

Australia, the sedimentary environments of the south coast of East Timor around

Betano consisted of steep wave-exposed beaches (Figure 4 a) which appear to be

strongly influenced by wave energy rather than tides. From examination of low tide

levels during sampling at the time of a full moon, and evidence of the highest water

excursion from debris, tides in the region appear to be approximately 3 4 m between

mean low water (MLWL) and mean high water (MHWL) levels. This covered an

approximate horizontal distance of 20m where measured. This suggests a beach slope

of 0.2. A schematic representation of the beach profile at a river mouth on the reef

platform is shown in Figure 3. Beaches away from the reef platform and not at river

mouths had a steeper profile and less noticeable drop in height behind the beach berm

than displayed in Figure 3 (see Figure 4 a).

Examination of sediments at high tide mark suggested the occurrence of

significant coral reefs offshore of the intertidal reef platform. Coral rubble, often

consisting of very large (~30 cm2) individual coral fragments, attests to the presence

of coral offshore as well as the high energy environment capable of transporting large

pieces of debris across the intertidal reef. At least seven separate species of coral

were evident based on skeleton morphology (Figure 5).

Sediments movement along the coast appeared to be largely east to west.

Aerial photographs show a sediment plume from the River Quelan stretching

westwards away from the study area (Figure 6). Sediment transport in the vicinity of

the reef platform seemed to be complicated by a headland to the east of the study area.

A large eddy of sediment was evident at the tip of the headland, with little long-shore

sediment transport around T4 - T6 (see chapter four, Figure 21).

Observations of several rivers entering the coast across sandy beaches also

suggested a general westward pattern of coastal sediment movement, at least during

the dry season. All rivers observed had a barrier bar at their mouth, with water

flowing westwards along the beach parallel to the bar before breaching (Figure 4 b).


(a)

(b)

Figure 4: Sandy beach environments of the south coast of East Timor around Betano showing (a) the steep wave-exposed beaches and (b) the typical barrier bar formation at river mouths forcing shore

parallel westward flow of rivers in the dry season.


Figure 5: Coral skeletons collected amongst beach rubble in the vicinity of T1 showing seven distinct skeletal morphologies, suggesting a diverse coral assemblage occurs offshore of the intertidal reef

platform.


(a)

(b)

Figure 6: Aerial photograph of: (a) the study region demonstrating the input of sediment into the coastal zone; (b) close-up of the mouth of the River Quelan showing the apparent westerly transport of

sediment (light arrow) (red dots are sediment sampling locations). Evidence of areas of significant deforestation are shown by heavy arrows. See chapter four for sediments in vicinity of reef platform

further east (Figure 21).


3.3.2. Sediment Grain Size

In all instances, sieving error as determined by GRADISTAT was below 1%

and generally below 0.2% (Appendix A). All sediments were classified as coarse to

very coarse sands, excluding S8 which was a fine sand. Apart from S9, sediments

were also well, to moderately well sorted. It should be noted that in a number of

instances sediments much larger than the largest diameter sieve (2mm) were evident

in the sample. This is particularly so for S1, with visual evaluation of the sample

suggesting it was more gravel in nature. The cut-off for classification of sediments as

gravel is 2mm.

3.3.3. Sediment Composition

The composition of sediment at beach and reef locations was very distinct.

Beach sediments were entirely terrigenous in origin, while reef sediments were

dominantly biogenic with little terrigenous material (Figure 7). The biogenic

composition showed a very strong contribution from coral, with up to 90% of all

grains being coral fragments. The highest contribution from coral fragments occurred

on the intertidal reef platform, and not at the offshore sites (S8 - S10). There were no

terrigenous sediment grains evident on the reef platform.

3.3.4. Sediment Cores

Sediment cores demonstrated influxes of terrigenous material to the coastal

environment. Both core one and two demonstrated alternating bands of terrigenous

sediments with biogenic sediments produced on the adjacent rock platform (Figure 8).

Layers of terrigenous material were many times thicker than the very thin bands of

biogenic material. Both cores were driven in as far as possible with C1 sampling

87cm of sediment and C2 54cm. In both instances solid obstructions seemed to halt

further core penetration, with C2 in particular showing evidence of large coral

fragments at its end (Figure 8 b).

Groundwater seepage over the rock platform was not evident. Only dry sand

could be recovered from core holes. Water observed to be seeping out of the beach

face over the rock platform at low tide was collected, but did not suggest freshwater

(having a salinity of 33.13).


0

10

20

30

40

50

60

70

80

90

100

S2 S10 S9 S8 T4-20

Site

% c

om

po

stio

n

Mollusc

Gastropod

Coral

Terrigenous

Figure 7: Composition of sediments collected from a beach site (S2) and the middle of the intertidal reef platform (T4-20), as well as sediments adjacent to the reef at 10, 20 and 30 m from the reef edge

(S8, S9 and S10, respectively).


(a) (b)

Figure 8: Composite images of cores one (a) and two (b), scale bar represents 5cm in both instances. A close-up of one section of core one (c) shows thick bands of dark terrigenous sediment alternating

with thin bands of light biogenic material (arrows).

(c)


3.4. Discussion

The sediments of the south coast of East Timor have been characterised for the

first time. The relative contributions of terrigenous and biogenic material

demonstrates the strong influence of fluvial flux on the coastal environment. The

degree to which material injected via rivers will influence marine ecosystems in the

region will be determined by local transport mechanisms and the structure of subtidal

communities. Both of these factors have only been qualitatively assessed and require

further investigation.

Given the high elevation and seasonal rainfall in catchments draining to East

Timor s south coast, a naturally high flux of fluvial sediment could be expected. In

addition, deforestation in the region, which is evident to varying extents in aerial

photographs, is likely to have enhanced sediment supply (e.g. see Figure 6 b and

Figure 21). It was anticipated that information from cores could be used to

demonstrate a temporal trend, and potentially an anthropogenic enhancement, in

sediment flux. However, the depth of sediment which could be sampled was

restricted by the underlying reef platform and it is like that high energy conditions

prevent sediment build-up over long time scales. Hence, trends in sediment flux

could not be examined in the study and are an important area for further investigation.

Offshore areas where sediment accumulates may potentially provide important

information on temporal trends in sediment supply which may be related to

anthropogenic activity.

Without more detailed sampling, including quantifying offshore sedimentary

environments and local oceanography, the transport of sediments within and away

from the nearshore zone is difficult to explain definitively. It would appear that

complex transport mechanisms operate redistributing sediments injected via rivers.

However, several general observations can be made. For instance, the presence of

sediments of terrigenous origin on the beach, as opposed to the biogenic sediments in

the vicinity of the reef, suggests that terrigenous sediments injected seasonally via

rivers are retained in the sandy beach habitat but not on the reef platform. There was

very little terrigenous material on the intertidal platform with only biogenic material

produced on and adjacent to the reef evident on the reef. Even small rivers, such as

those flowing over the reef platform, have the capacity to inject significant amounts of

terrigenous sediment into the nearshore zone. In fact, small rivers are thought to


contribute a greater discharge of sediment due to a smaller storage capacity and

greater response to episodic events supplying sediment such as floods and landslides

(Milliman et al., 1999). The structure of cores demonstrates the significant seasonal

influx of sediments over the reef even by small rivers, raising the question as to the

fate of this material in the nearshore zone. Observations suggest that sediments may

be subject to longshore or offshore transport, depending particularly on gain size.

The lack of terrigenous material on the reef platform can be explained in

several ways. Firstly, terrigenous sediment entering the coastal environment over the

reef may be advected away from the reef, contributing to the formation of the beach.

Observations suggested that longshore transport of sediments in the region is likely to

be east to west. A similar westward movement of large amounts of terrigenous

sediment has been observed on the south coast of the nearby islands of Sulawesi

(Milliman et al., 1999). Around Betano, sediments advected from the reef platform

may contribute to the supply of terrigenous material forming the sandy beach west of

the reef. However, the lack of biogenic material in beach sediments argues against an

oceanographic link between the beach and reef habitats.

Another factor that may contribute to the redistribution of terrigenous material

is the fact that this material is introduced to the marine environment in freshwater

plumes, which may enhance its offshore transport. During the wet season, terrigenous

material is introduced to the coast in freshwater plumes and hence may not settle onto

the reef at all. Furthermore, any terrigenous material that does settle onto the reef in

the wet season is likely to have been advected away by the time sampling was

conducted in July due to wave action and longshore currents. Terrigenous material

may be carried offshore in the river plumes before settling from the water column,

and perhaps being deposited on the beach as a result of shoreward transport of

bedload.

The offshore transport of sediments is further evident in the lack of fine

sediments of terrigenous origin. While in situ measurement of sediments supplied to

the coast in flowing rivers is required to fully elucidate the nature of fluvial sediments

(e.g. Neil et al., 2002), the dominance of coarse grains suggests that finer terrigenous

material likely to be supplied by rivers is lost from the system. The loss of fine

material from the nearshore zone is likely to be enhanced due to wave exposure (see

Pulfrich et al., 2003). For instance, there was much less sediment observed on the

western edge of the intertidal reef where wave exposure is greater (pers. obs.). The


width of the continental shelf and the direct connection of rivers to the coast without

intervening estuaries suggests that the majority of terrigenous sediment, particularly

finer material, my be transported further offshore. Such material may be contributing

to infilling of the Timor Trench (D.Haig, pers. com.), aided by transport associated

with freshwater plumes from rivers.

The ability of terrigenous sediments to affect nearshore marine habitats will be

determined to a large extent by their retention in the nearshore zone. It would appear

that fine terrigenous material in particular is transported offshore. The extent to

which this occurs will determine the influence of sedimentation on nearshore

ecosystems. It may be that most material is lost to the deep ocean due to the

proximity of the continental slope adjacent to East Timor and the high energy

environment. On the other hand, anectodal evidence from native fisherman suggests

that approximately 50m offshore from the intertidal reef platform, the benthos

becomes dominated by a muddy substrate. This could potentially be the fate of fine

terrigenous material injected via rivers and may influence the type of biological

communities occurring offshore.

If significant deposition of fine terrigenous material is prevalent offshore,

impacts on biological communities from enhanced sedimentation could be expected.

In particular sediment composition suggests that there are significant coral formations

offshore of the intertidal reef platform. The diversity of coral skeleton morphologies

observed in this study almost certainly underestimates offshore diversity, since

species likely to be eroded into small pieces, such as branching growth forms, were

not examined in the survey, which was restricted to large coral rubble.

The presence of coral communities in an area subject to very high sediment

influx could be considered surprising. However corals have been shown to be capable

of adapting to both natural and anthropogenically induced very high rates of

sedimentation (e.g. Barnes & Lough, 1999). A study of coral communities on the

north and east coast of East Timor have demonstrated adaptation to naturally high

terrestrial sediment flux entering the coastal zone (Hantoro et al., 1997). However,

Hantaro et al. (1997) also found that even reefs far from river mouths were found to

be influenced by sediment-rich longshore currents, restricting coral to sheltered

embayments with little water movement and sediment resuspension. This suggests

that anthropogenically enhanced sedimentation also has the capacity to have broad

reaching impacts on subtidal coral communities on East Timor s south coast, should


local oceanography result in sediment retention in the nearshore zone. Whether

sediment is delivered to the substratum or simply advected through the system is

acknowledged as an important consideration in evaluating the effects of

anthropogenically enhanced sedimentation on coral reefs (Torres et al., 2001).

Whether anthropogenic activities are resulting in increased sediment flux, and the fate

of these sediments, requires further investigation on East Timor s south coast in order

to determine the potential impacts of land-based activities on nearshore marine

habitats.

Through documenting the coastal sediments around Betano, this study may

serve as a useful baseline against which to assess the impacts of further development

in the region. Developments which alter the flux of sediments to the coastal zone, as

well as the transport and retention of sediments in this zone, have the potential to

impact the marine environment of the region. Land-based activities such as

deforestation may increase sediment flux and hence lead to impacts through direct

smothering of organisms, increased turbidity and light attenuation, and increased

transport of contaminants. Anecdotal evidence suggests that options for

establishment of a port around Betano may be being explored. Such physical

alteration may interrupt longshore sediment transport and lead to greater retention of

sediments, particularly of small grain size, which are likely to result in environmental

changes. This study has made preliminary steps towards gaining baseline data which

is essential for assessing the impacts of such developments on the coastal environment.

3.4.1. Conclusions

The potential for strong links between the terrestrial and marine environment

on East Timor s south coast as a result of fluvial sediment flux has been established

around Betano. While local transport and fate of sediments injected into the

nearshore zone requires further investigation, the potential for impacts as a result of

anthropogenic enhancement of sedimentation appears high. This is particularly so

given evidence suggesting the presence of significant subtidal coral communities

which may be especially susceptible to enhanced sedimentation. This study

represents a preliminary step towards providing baseline data against which changes

in coastal sediments as a result of development may be assessed.


4. Baseline Survey of Intertidal Benthic Biomass and Composition: An assessment of rapid survey techniques and anthropogenic impact

4.1. Introduction



1989; Gerges, 1994; Christie & White, 1997; Thia-Eng, 1999; Burgess, 2000; Bellan

& Bellan-Santini, 2001; de Jonge et al., 2002; Tran et al., 2002; Li & Daler, 2004).

The central south cost of East Timor around the village of Betano is currently

relatively sparsely populated with little infrastructure. There is no power or running

water and local people largely lead a subsistence life of slash and burn agriculture and

fishing (Soares, 2001). Development is expected to continue in the region, and across

the nation as a whole, as attempts are made to recover from a long history of foreign

rule and violence. The necessity for financial recovery suggests that there is the

potential for economic, rather than environmental, considerations to be given priority

(but see Anderson & Deutsch, 2001). The potential exists for unmanaged

development to result in significant impacts on the marine environment as has been

documented worldwide in both developing and developed nations.

A variety of developments with the potential to impact the marine

environment have occurred in the region, or have the potential to do so. The long

history of foreign rule in the country has seen significant environmental degradation

over the last 500 years (Carrascalao, 2001). Most notably, large scale deforestation

and exploitation of the terrestrial environment occurred during both Portuguese and

Indonesian rule (Carrascalao, 2001). The Indonesian policy of transmigration of

people for easy suppression of dissent resulted in coastal populations increasing many

orders of magnitude (e.g. Bouma & Kobryn, 2004). This led to increased pressure on

the surrounding coastal environment as the displaced people competed for scarce

resources (Bouma & Kobryn, 2004).

In the modern, independent East Timor, there are a variety of other

developments likely to occur in the coastal environment. Oil and gas exploration is

already occurring in coastal regions and tourism developments are likely (e.g.

Sandlund et al., 2001). The coastal area around Betano is largely exposed and lacks a

suitable port, which limits the use of vessels in the region and development of


commercially viable exploitation of the marine environment. Fisheries catch taken

south of Betano is currently shipped by sea to Dili for sale (Mounsey, 2001). As

remarked earlier, anecdotal evidence suggests that options for establishment of a port

in the region may be being explored by the nation s government in an attempt to

enhance the capacity for development on the south coast.

In this study the intertidal environment is used as a proxy to assess general

impacts of current anthropogenic activities on the nearshore coastal environment

around the village of Betano. Intertidal habitats were considered likely to be

particularly good indicators of human impacts on the broader marine environment for

several reasons. These habitats are closely ecologically linked to subtidal habitats and

form a link between concentrations of human population and the marine environment.

They may be most susceptible to impacts due to their proximity to land-based sources

of pollution, and hence may give advance indication of activities likely to impact

subtidal habitats (e.g. Morrison & Delaney, 1996). The link between the terrestrial

and marine environment in terms of sediment supply in this region, as a result of river

input, was demonstrated in Chapter Three. Furthermore, these habitats are generally

readily accessible for exploitation, as well as assessment, and so represent a means to

readily determine the impacts of human populations. Logistical and safety

considerations were of particular importance in this study, with limited infrastructure

placing limitations on the level of investigation achievable.

The specific aims of the study were to: (a) document the biota of intertidal

habitats in the region for the first time; and, in doing so, (b) determine if

anthropogenic activities have impacted this biota, via fluvial flux of sediments and

contaminants and (c) explore survey techniques for rapidly assessing marine

ecosystems, particularly those applicable for use in developing nations with little

infrastructure or financial resources. Baseline data is essential for evaluating and

managing the impacts of development on the marine environment and it was hoped

that this study would provide a baseline to enable assessment of impacts on the

marine environment resulting from continued development in the region.


4.2. Materials & Methods

4.2.1. Study Site

The nearshore coastal zone around Betano on the south coast of East Timor is

characterised by steep, wave-exposed sandy beaches and an extensive wave-cut

intertidal reef platform. The sandy beach dominates the coastal zone west of the

village to the mouth of the River Quelan, while to the east the reef platform extends

for approximately 13 km along the coast (Figure 9). This phase of the study focuses

on the biota of the reef platform. The reef platform is composed of beach rock at its

upper margin and wave-cut carbonate limestone with evidence of relict coral reef

across the majority of the flat portion of the platform (average width ~ 80 100m)

(Figure 10). Characteristic of most of the south coast of East Timor, the platform is

crossed by a number of large and small rivers which flow seasonally. Above the

platform there is approximately 20m of steep sandy beach interspersed with

beachrock extending to the high tide mark. The seaward edge of the platform ends

abruptly, dropping rapidly to about 6m depth. Tides in the region are macrotidal with

a range of about 2.5m (MHW- MLW).

Sediment samples for analysis of chlorophyll concentration were obtained

along the beach west of Betano in conjunction with sediment sampling described in

the chapter three (S1 S7, Figure 2). The sandy beach environment is also described

in the preceding chapter.

4.2.2. Sampling Design

Approximately 3.7 km of the intertidal reef platform east of Betano was

surveyed at the start of the dry season (late June and early July 2004) in a total of 90

25 x 25cm quadrats along six randomly placed transects (T1 T6). Placement of

transects was such that T1 and T2 were largely isolated from rivers; T3, T4 and T5

were located close to the mouth of rivers which flow to the sea in the wet season; and

T6 was adjacent to the village of Salihasan.

Along each transect the identity and percentage cover of sessile organisms

were recorded at the top of the reef platform (~20 m from the high tide mark) and at

10, 20 30 and 40m across the platform. Sampling was restricted to 40m due to the

width of the platform at some sites and wave exposure at the outer edge. At each

distance three randomly placed replicate 25 x 25cm quadrats were established and


photographed using a Sony T1 digital still camera. In addition to sessile species cover,

the number of individuals of a species of brittle star (ophiuroid, Echinodermata:

Ophiuroidea) per quadrat was also recorded for T5 and T6, with randomised quadrat

counts performed at T4 (not at the set distances specified above). Physical

measurement (temperature and salinity) for each transect were measured with a

Yeokal Model 611 where water depths at low tide allowed immersion of the probe.

Representative samples of each species observed, including the ophiuroid,

were collected, close-up photographs taken and specimens stored in 70% ethanol for

transport to Perth.

Sediment cores for chlorophyll analysis were taken at sites 1 7 described in

the previous chapter stretching from the mouth of the River Quelan to Betano. At

each site 3 replicate cores (20 mm diameter x 10 mm deep) were taken at the waters

edge at low tide.

4.2.3. Image Analysis

Percentage cover of the dominant brown algal macrophyte along T5 obtained

using the NIH ImageJ processing software (Rasband, 2004) was compared to the

visual estimate obtained in the field to investigate the usefulness of image analysis for

marine surveying. Retrospective counts of the ophiuroid were also undertaken for

each quadrat from photographs and compared to counts performed in the field (where

significant counts were performed, i.e. T5 and T6).

Visual estimates were performed simply by estimating the percent coverage of

each species observed within each quadrat. This included moving overlying cover,

such as macroalgae and easily moveable rocks, and estimating cover of underlying

species.

Analysis of cover in digital photographs was undertaken using ImageJ,

focussing on determining the cover of the dominant brown alga. The analysis

involved a number of steps. Firstly, RGB JPEG images of each quadrat containing

the brown alga were converted to 8-bit images (Figure 11 a, b). Secondly, a threshold

was performed highlighting pixels with intensity between 50 and 120 units (Figure 11

c). These limits were experimentally determined through examination of the best

range for highlighting the brown alga in each image. Once thresholding was complete,

known areas of brown algae (noted in examination of the original RGB image) were


Figure 9: Location of the six sampling transects (T1 T6) on intertidal rock platform east of Betano. Note that T3, T4 and T5 are located at the mouth of small rivers and T6 is adjacent to the village of

Salihasan.


(a)

(b)

Figure 10: Intertidal reef platform showing: (a) typical zonation consisting of sandy beach delineated from wave-cut carbonate limestone platform by beachrock; and (b) evidence of relict coral which

formed the wave-cut platform.


selected and the area calculator plugin of ImageJ used to determine total area and hence percent cover (Figure 11 d).

4.2.4. Sediment Chlorophyll Analysis

The concentration of sediment chlorophyll a and phaeophytin was determined

fluorometrically using the method of Parsons et al. (1984). Sediment samples were

extracted for 24 hours in 90% ethanol under refrigeration in the dark. Flouresence

readings were taken with a Turner fluorometer before and after acidification with 1 M

hydrochloric acid.

4.2.5. Data Analysis

A variety of analyses were performed using a number of software packages,

with the multi-species nature of the data lending itself best to multivariate techniques.

Sampling efficiency was estimated using species-area relationships and the EstimateS

software (Colwell & Coddington, 1994; Colwell, 2004). Multivariate analyses were

undertaken using the PRIMER V5 for Windows package (Clarke & Gorley, 2001).

Non-metric multidimensional scaling (MDS), analysis of similarity (ANOSIM) and

similarity percentages (SIMPER) routines were used to investigate the community

structure along the reef and to test for statistically significant differences in species

composition. Univariate analyses of species richness and diversity were also

undertaken.

Community diversity for each quadrat was estimated using the Shannon-

Weaver information index (H ; Shannon and Weaver (1949)). This index calculated

species contribution to live cover (the total space occupied by living organisms):

,plnp-H ii

where pi is the proportion of all occupied space occupied by the i-th species (% cover

of the i-th species / total cover in each quadrat).

Species-area curves and species richness estimators were calculated for the

entire survey based on 1000 permutations in EstimateS (Colwell & Coddington, 1994;

Colwell, 2004). Two species richness estimators were employed: MM Mean (based

on the Michaelis-Menton equation) and Chao 2 (Chao, 1987). A species-area or

species-accumulation curve is a plot of the cumulative number of species discovered


(a)

(b)

(c)

(d)

Figure 11: Examples of methodology used to digitally determine macrophyte cover using the NIH Image J software: (a) Original JPEG image is converted to (b) an 8-bit image and (c) thresholds applied to highlight the areas of brown algae and (d) large regions of brown algae subjectively selected (black

arrows) and area calculated.


as a function of the effort expended to find them (i.e. the number of quadrats sampled)

(Colwell & Coddington, 1994).

If an asymptote is not reached it suggests that more samples would be required

to fully capture the diversity of the community (Clarke & Gorley, 2001).

Multivariate analyses were based on a matrix of Bray-Curtis Similarity values

calculated from 4th root transformed species percent cover. The Bray-Curtis

similarity coefficient, for the similarity between the jth and kth samples, Sjk, has two

equivalent definitions:

p

i ikij

p

i ikij

p

i ikij

p

i ikij

jk

yy

yy

yy

yy

1

1

1

1

,min2100

1100S

This results in a similarity value between each quadrat based on the transformed

percent cover of each species present in the two quadrats.

The Bray-Curtis coefficient was chosen as it is widely used in ecological work,

is seen as one of the most reliable performers (Clarke, 1993) and because joint

absences (species lacking from both samples being compared) have no effect on the

value of S (Clarke, 1993; Clarke & Warwick, 1994). As Field et al. (1982) put it:

Taking account of joint absences has the effect of saying that estuarine and abyssal

samples are similar because both lack outer shelf species . The data in this study

contained many joint absences and independence of joint absences is a desirable

property not shared by all similarity coefficients (Clarke & Warwick, 1994). Using

the Bray-Curtis coefficient meant that transects along the rock platform were not

calculated as similar because they both lack certain species.

The choice of transformation was made on the basis of experimentation with

different transforms and at the recommendation of Clarke and Warwick (1994). The

4th root transformation represents a good balance between retaining hard-won

quantitative information and downplaying the species dominants/taking into account

rarer species (Clarke, 1993; Clarke & Warwick, 1994; Thorne et al., 1999). As one of

the aims of the survey was to characterise the intertidal community and detect


differences due to the influence of riverine input, a balance between the influence of

rare and dominant species on similarity values was considered essential. Rarer

species may be important from a conservation perspective and may be more affected

by anthropogenic disturbance.

Ordination of percent cover data was performed using non-metric

multidimensional scaling (MDS). The purpose of MDS, introduced by Shepard

(1962) and Kruskal (1964), is to construct a map or configuration of samples, in a

specified number of dimensions, which attempts to satisfy all the conditions imposed

by a rank (dis)similarity matrix (Clarke & Warwick, 1994). MDS was chosen over

other ordination techniques due to its flexibility (Clarke, 1993; Clarke & Ainsworth,

1993; Clarke & Warwick, 1994). The reliability of the MDS ordination is indicated

by its stress value. Stress < 0.1 corresponds to a good ordination with no real risk of

drawing false inferences and stress < 0.2 still produces a useable picture, although for

stress closer to 0.2 there is the potential to mislead (Clarke, 1993). For stress > 0.1 a

higher dimensional plot may show a somewhat different picture (Clarke, 1993). Plots

presented are two-dimensional and based on 100 restarts, however the influence of

varying the number of restarts on observed stress values (i.e. the reliability of the

ordination) was also investigated.

Statistically significant differences between transects was investigated using a

two- way nested ANOSIM (analysis of similarity) with distance from shore nested

within transect. Five thousand permutations were performed (Thorne et al., 1999) on

the Bray-Curtis similarity values (calculated from 4th root transformed percent cover

data).

The one-way ANOSIM test can be applied to the (rank) similarity matrix

underlying ordination or classification of samples and is a distribution-free analogue

of one-way ANOVA (Clarke, 1993). The test evaluates the similarities of samples

within sites as well as between sites. If rw is defined as the average of all rank

similarities among replicates within sites, and rb is the average of rank similarities

arising from all pairs of replicates between sites, then a suitable test statistic is


2

1-nn M where

2

Mrr

R wb

and n is the total number of samples under consideration (Clarke, 1993; Clarke &

Warwick, 1994). The test statistic R is such that: R can never technically lie outside

the range (-1,1); R = 1 only if all replicates within sites are more similar to each other

than any replicates from different sites; R is approximately zero if the null hypothesis

is true, so that similarities between and within sites will be the same on average (i.e.

no significant difference between sites) (Clarke, 1993; Clarke & Warwick, 1994).

The R statistic itself is a useful comparative measure of the degree of separation of

sites, though one is often initially concerned with the simple question of whether it is

significantly different from zero (Clarke, 1993). The significance of R is calculated

by a permutation test in the following way: further R statistics are calculated for

arbitrarily rearranged site labels in the similarity matrix and the significance is then

calculated from the relationship between these R statistics and the original R, derived

from the true site allocation of samples (Thorne et al., 1999).

Very few, if any, assumptions are made about the data in constructing a one-

way ANOSIM test, and it is therefore very generally applicable (Clarke & Warwick,

1994). There is also no restriction to a balanced number of replicates (Clarke &

Warwick, 1994). Unlike the one-way ANOSIM, the two-way ANOSIM is not the

analogue of a test for treatment main effects in a univariate two factor ANOVA

(Clarke, 1993). The two-way ANOSIM is equivalent to pooling the sums of squares

for the main effects and interactions, and comparing this with the residual to give the

overall test for the presence of a treatment effect (Clarke, 1993).

Identification of species primarily responsible for significant between-transect

differences (as identified by ANOSIM and MDS) was achieved using the SIMPER

(similarity percentages) routine in PRIMER. By looking at the overall percentage

contribution each species makes to the average dissimilarity between two groups (an

average of all possible pairs of dissimilarity coefficients, taking one sample from each

group), one can list species in decreasing order of importance in discriminating the


two sets of samples (Clarke & Gorley, 2001). Data used in SIMPER analysis had the

same transform (4th root) performed on it as that used to produce the MDS ordination.

A cut off for cumulative species contributions to similarity was arbitrarily specified at

30 %.

4.3. Results

4.3.1. Physical Parameters

In a number of cases there was insufficient water remaining on the platform at

low tide to allow measurement of physical parameters and data was only obtained for

T1 T4. There was no noticeable trend in physical parameters either between

transects or across the platform. Water temperatures were high, being 26ºC or above.

Similar to analysis of water entering the rock platform from the beach face conducted

in Chapter Three, there was no noticeable influence of freshwater across the platform

at the time of sampling.

4.3.2. Visual/Digital Comparison

Digital analysis of the cover of the dominant brown alga along transect five

was significantly related to visual estimates obtained in the field as revealed by linear

regression (digital cover = 0.6044 × visual cover, F1,14 = 55.25, P < 0.001, r2 = 0.800)

and the samples were not significantly different (ANOVA, F1,28 = 0.3469, P = 0.561).

This suggests that both techniques may be employed to estimate the cover of the

dominant macroalgae. However, digital analysis was ineffective at detecting small

species which typically occur under other species and hence are not observable in

images. Sampling visually in the field was the only means of capturing these species

and hence subsequent analysis focused on data obtained visually in the field rather

than that calculated from digital images.

Photographic counts of the number of brittle stars (ophiuroid) individuals also

underestimated field observations. A significant relationship was revealed between

field and photo counts for transects five and six (photo # = 0.565 × field # - 0.4409,

F1,28 = 56.12, P < 0.01, r2 = 0.667). However, photo and field estimates were

significantly different (ANOVA, F1,58 = 5.839, P < 0.05) with digital analysis

underestimating field observations by an average of 62.23%. While digital counts

underestimated ophiuroid numbers, they were the only means available for transects

where counts were not performed in the field. Analysis of ophiuroid numbers below


relied on data obtained from both sources, acknowledging the probable

underestimation provided by photographic counts.

4.3.3. Sessile Taxa

A total of 27 taxa of sessile organisms were sampled composed of 18 taxa of

algae, three sponges (poriferans), two coral (scleractinians), two ascidians, one

anemone (cnidarian) and one foraminifer (Appendix B). Currently only the

foraminifer has been positively identified to species level. A species-area curve for

all transects suggests that sampling was sufficient to fully elucidate the sessile

community occurring on the reef platform (Figure 12). The estimated maximum

number of species by MM Mean and Chao2 of 27.48 and 27.63 respectively was very

close to the number of species (27) actually observed.

The composition of species varied between sites with average species richness

across an entire transect ranging between about 1.5 and 4 species per quadrat (Figure

13). In general, species richness appeared lower at the western end of the survey area

increasing westwards. A similar increase in diversity (H ) westwards was also

evident (Figure 14). A reliable MDS ordination (stress = 0.11) failed to separate sites

based on species composition, however ANOSIM analysis suggested that T1 and T2

were significantly different from T4, and T2 from T6. SIMPER analysis identified

species characteristic of each transect and those contributing most to significant

differences between transects (Table 3 and Table 4). The brown alga was the most

abundant species along T1, T2 and T5, whereas T4 was characterised by an ascidian,

and T3 and T6 by a green alga (Caulerpa sp.). Significant differences between

transects were largely driven by the brown alga which had greater average abundance

along T1 and T2 than along T4 and T6. In addition the ascidian abundant at T4 was

absent from T1 and T2. The Caulerpa sp. characteristic of T6 also contributed to the

significant difference with T2.

A noticeable trend in cover with distance from shore was evident for most

transects. In general total average cover per quadrat increased with distance from

shore, with the exception of T3 where only bare space was sampled 20m from the

shore (Figure 16). Transect three was distinct from other transects in its topography

with an approximately 1m deep pool occurring in the mid section compared to

relatively flat topography along the other transects. Ordination revealed a distinct

separation of the shoreline quadrats (0m) from quadrats further out (Figure 17).


ANOSIM analysis suggested that species composition varied significantly with

distance (Table 2). SIMPER analysis revealed that the shoreline (0m) was

characterised by another Caulerpa sp., the nearshore (10m) by a brown alga of the

genus Padina and the rest of the platform by the abundant brown alga (Table 5)

4.3.4. Ophiuroid

Brittle stars were only sampled along transects four, five and six at 10m or

greater from the shore. The average number of individuals per quadrat seemed to be

highest for T4 with up to 20 individuals in a single 25 × 25cm quadrat (Figure 18).

The approximately 60% underestimation of ophiuroid numbers by photographic

counts, evident in Figure 18 and discussed above, suggests that while no ophiuroids

were sampled along T1 T3, it is possible that they were present in small numbers or

covered by sessile species and so not sampled through photographic analysis.

4.3.5. Sediment Chlorophyll

There was no distinct spatial pattern in chlorophyll a or phaeophytin

concentrations in relation to proximity to the mouth of the River Quelan (Figure 19).

Chlorophyll a concentrations were very low, below 0.05 mg/m-2 (50 g/m-2), at all

sites. Also at all sites, the ratio of chlorophyll:phaeophytin was well below 1, ranging

between 0.097 and 0.28.


Table 1: Physical parameters (pH, salinity and temperature) measured at each distance across the intertidal reef platform for transects one four. Measurements could only be achieved where sufficient

water remained at low tide

Transect Dist pH Sal Temp

0 - - - 10 6.91 32.91 27.01 20 6.92 32.86 26.71 30 6.91 32.87 26.58

T1

40 - - - 0 - - -

10 6.68 33.23 28.85 20 6.69 33.22 27.98 30 6.71 33.21 27.57

T2

40 6.77 33.22 27.39 0 - - -

10 - - - 20 7.27 33.33 27.48 30 7.14 33.22 27.34

T3

40 6.91 33.00 27.37 0 7.24 33.78 29.44

10 7.14 33.47 28.77 20 - - - 30 - - -

T4

40 - - -


0

5

10

15

20

25

30

35

0 20 40 60 80 100

Quadrats

Cu

mu

lati

ve #

of

Sp

ecie

s

Figure 12: Species-area curve (black line) for the entire survey showing 95% confidence levels (dashed lines). Note the curve appears to be nearing an asymptote suggesting sampling fully captured

the diversity of sessile taxa on the intertidal reef platform.

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

5

T1 T2 T3 T4 T5 T6Transect

Ric

hn

ess

Foraminifera

Cnidarian

Coral

Ascidian

Porifera

Alga

Figure 13: Average species richness per quadrat of sessile taxa for each of the six transects across the intertidal reef platfrom.


0

0.2

0.4

0.6

0.8

1

1.2

T1 T2 T3 T4 T5 T6Transect

Div

ersi

ty (

H')

Figure 14: Average diversity (H ) for each of the six transects increasing west (transect one, T1) to east (transect six, T6) along the intertidal reef platform.

Stress: 0.11

Figure 15: MDS plot based on 4th root transformed percent cover data discriminating quadrats by transect (transect one: black upwards triangle; two: downwards triangle, three: black square, four:

diamond, five: black circle; six: cross). Note lack of separation by transect and stress = 0.11.


0

20

40

60

80

100

120

140

160

180

200

0 10 20 30 40 50

Distance [m]

Per

cen

t C

ove

rT1

T2

T3

T4

T5

T6

Figure 16: Average percent cover at each distance from the shore for each transect. Cover generally increased with distance from the shore. A noticeable drop in cover at 20m for T3 coincided with a rock

pool containing significant water at low tide.

Stress: 0.11

Figure 17: MDS plot based on 4th root transformed percent cover data discriminating quadrats by distance from shore (0m = black upwards triangle, 10m = downwards triangle, 20m = black square,

30m = diamond, 40m = black circle). Note separation of 0m quadrats and stress = 0.11.


Table 2: Results of two-way nested ANOSIM test with distance nested within transect showing transects significantly difference by pairwise tests.

Factor Sample Statistic (Global R)

Significance Level

Number of Permutations

Number of permutated statistics

Global R Global Tests

Distance 0.559 0.0 % 5000 0 Transect 0.128 2.8 % 5000 141

Pairwise Tests

T1, T4 0.42 1.6 % 126 2 T2, T4 0.432 1.6 % 126 2 T2, T6 0.292 4.0 % 126 5

Table 3: Results of SIMPER test identifying species characteristic of each transect (Av.Abund. = average abundance in that transect, Av.Sim. = average similarity, Contibution (%) = contribution to

within transect similarity, Cumulative (%) = cumulative contribution to similarity with cut off specified at 30%).

Transect (Av. Sim.)

Taxa Av. Abund.

Av. Sim. Contribution (%)

Cumulative (%)

1 (38.06)

Brown Alga 1 39.5 27.34 71.84 71.84

2 (41.54)

Brown Alga 1 56.92 35.5 85.48 85.48

3 (22.68)

Caulerpa 1 5.5 8.21 36.18 36.18

4 (34.58)

Ascidian 1 30.4 11.07 32 32

Brown Alga 1 27.08 13.16 29.9 29.9 5

(44.00) Caulerpa 1 6.5 9.31 21.15 51.05

Caulerpa 1 5.13 5.05 20.1 20.1 6

(25.14) Padina 7.17 5.05 20.07 40.17


Table 4: Results of SIMPER test identifying species responsible for significant differences between transects a and b, as revealed by pairwise ANOSIM test (Av.Abund. = average abundance in that

transect, Av.Diss. = average dissimilarity between transects, Contibution (%) = contribution to between transect dissimilarity, Cumulative (%) = cumulative contribution to dissimilarity with cut off specified

at 30%)

Transects a, b (Ave. Diss.)

Taxa Av.

Abund (a)

Av. Abund

(b)

Av. Diss

Contribution (%)

Cumulative (%)

Brown Alga 1 39.5 13 17.04 20.15 20.15 1,4 (84.56) Ascidian 1 0 30.4 13.18 15.58 35.73

Brown Alga 1 56.92 13 19.64 23.32 23.32 2,4 (84.21) Ascidian 1 0 30.4 13.53 16.06 39.39

Brown Alga 1 56.92 18 16.4 20.09 20.09 2,6 (81.65) Caulerpa 1 7 5.13 8.23 10.08 30.17

Table 5: Results of SIMPER test identifying species characteristic of each distance from shore (Av.Abund. = average abundance in that transect, Av.Sim. = average similarity, Contibution (%) =

contribution to within distance similarity, Cumulative (%) = cumulative contribution to similarity with cut off specified at 30%).

Distance (Av. Sim.)

Taxa Av. Abund. Av. Sim. Contribution (%)

Cumulative (%)

0m (23.55)

Caulerpa 2 4.27 9.97 0.55 42.32

10m (24.47)

Padina 7.82 12.35 0.83 50.48

20m (36.79)

Brown Alga 1 35.67 13.83 0.59 37.6

30m (42.12)

Brown Alga 1 37.33 20.62 1.02 48.96

40m (46.46)

Brown Alga 1 49.44 31.05 1.27 66.82


0

2

4

6

8

10

12

14

16

T4 T5 T6

Transect

Ric

hn

ess

Digital

Visual

Figure 18: Average number of brittle stars (ophiuroid) per quadrat (25 × 25 cm) for T4 T6 determined from photographic (digital) and field (visual) counts.

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

S1 S2 S3 S4 S5 S6 S7

Site

mg

/m^-

2

Phaeo [mg/m -̂22]

Chl-a [mg/m -̂2]

Figure 19: Spatial pattern of benthic algal biomass, in terms of chlorophyll a and phaeophtyin, in sediments at increasing distances from the mouth of the River Quelan (S1 - S7). See Chapter 3 for

details of sampling sites S1 - S7.


4.4. Discussion

This study represents a preliminary assessment of nearshore marine biota on

the south coast of East Timor and was achieved using rapid, simple and cheap survey

techniques. The composition of intertidal biota has been documented for the first time,

and suggests that current anthropogenic impacts appear to be minimal. The data

obtained may serve as a baseline against which to assess the impacts of further

development. The study also demonstrates that while there may be advantages to the

use of rapid assessment techniques, such as photographic surveys, in regions with

limited infrastructure and resources, the limitations of these techniques must be

assessed and acknowledged.

The rapid and simple visual assessment of cover of sessile species was a very

effective means for describing the community composition on the reef in an accurate

manner. Visual estimating has been found to one of the most accurate means of

determining percentage cover of sessile species (e.g. Meese & Tomich, 1992; Dethier

et al., 1993). The agreement between statistical estimates of species richness and the

number of species actually sampled underscores the effectiveness of the technique

and its potential for application in developing nations where logistical and financial

considerations prevent more in-depth investigations. More detailed studies using

expensive and difficult to obtain equipment, highly trained personnel and potentially

dangerous activities, such as SCUBA diving in crocodile inhabited waters, may be

necessary for certain habitats and studies. However, this study has demonstrated that

a preliminary, rapid assessment of biological composition and anthropogenic impacts

can be achieved in infrastructure poor regions with the assistance of relatively

untrained personnel.

While the use of photographic techniques was also generally successful in the

way they was applied, there were mixed results suggesting a limited applicability.

Analysis of photographs was successful at estimating the cover of the dominant

brown alga, comparing well with visual estimates obtained in the field. On the other

hand the technique did not detect cryptic species, or those hidden by the brown alga.

For instance photographic counts of the ophiuroid grossly underestimated the

numbers observed in the field. The limitation of photographic and video surveys of

marine biota to non-cryptic taxa, as well as certain environmental conditions such as

good visibility, has been noted by a number of authors (e.g. Meese & Tomich, 1992;


Edmunds et al., 1998; Segal & Castro, 2001). A further consideration is that

comparison of photographic or video surveys to data obtained in the field should be

considered essential for determining the relative efficiency of the technique at

sampling the desired taxa (e.g. Meese & Tomich, 1992). It may be that assessments

of anthropogenic impact will focus on only a few taxa likely to demonstrate change,

such as the brown alga in this study or coral in subtidal investigations. In such cases

video and photographic surveys may be a useful means of rapidly and easily assessing

anthropogenic impact, with the advantage of a permanent record available for

multiple analyses (Carleton & Done, 1995).

This study also suggests, as noted by Samways and Hatton (2001), that the use

of Clarke and Warwick s (1994) manual and associated software is particularly useful

in analysing data gathered about multi-species assemblages by rapid survey

techniques. The multivariate techniques employed in this study are likely to be

particularly useful for detecting the impacts of development on marine communities

and are readily applicable to assessments in data-poor developing nations (e.g. Clarke,

1993; Clarke & Ainsworth, 1993).

On the basis of the multivariate analysis of species composition obtained from

the visual field survey, it would appear that current anthropogenic impacts may not be

sufficient to have significant impacts on the intertidal biota of the region. Significant

differences in species composition revealed between transects along the coast do not

appear to be related to human activities such as land-based sources of contaminants.

Differences between transects were not detected as would be predicted a priori based

on land-based human impacts emanating either from point sources such as rivers or

from the village of Salihasan.

While no overall effect on community composition could be directly related to

riverine point sources, the potential for riverine input and local oceanography to

influence individual species was evident to some extent in this study. This could be

expected given the strong fluvial link between the land and marine environment

established in chapter three. Two species which had similar, distinct distributions

within the study area may have been influenced by supply and retention of organic

matter on the reef platform due to river input and local oceanography. The ophiuroid

and the ascidian were confined to the eastern portion of the survey area, which may be

related to the presence of the river mouth between T4 and T5. These species were

sampled in very high abundance along T4, and to a lesser extent along T5 and T6, but


were not evident in the western portion of the survey (T1 T3). The very high

abundance (as high as 80 individuals m-1) of the ophiuroid (see Figure 20) and the

space domination by the ascidian (average 30.4% cover) suggests that some process

lacking along T1 T3 must operate to support these species along T4 T6. The most

distinguishing feature between these two groups is the presence of the river mouth

between T4 and T5.

The potential for the river to support the ophiuroid and ascidian populations

observed may be explained by an enhanced supply and retention of sediments and

organic matter. As discussed in chapter three, aerial photographs of the region

demonstrate the capacity for rivers to inject sediments into the nearshore zone across

the reef platform and the potential for sediments to be retained due to a headland east

of T6 limiting longshore transport (Figure 21). In the vicinity of T4 in particular,

there was evidence of fine sediments being trapped by turfing algae (pers. obs.),

which may be indicative of an increased supply of organic matter at the mouth of the

river and reduced dispersal due to currents. While the ophiuroid and ascidian, like

many of the taxa sampled, have yet to be identified to species level, both species, like

many benthic communities, are likely to be good indicators of organic matter

enrichment (Nilsson, 1999; Grall & Chauvaud, 2002).

Independent of the supply of organic matter, the flow of freshwater alone may

have increased the abundances of the ophiuroid and ascidian. While there was no

evidence of freshwater influencing the platform at the time of sampling (see also

chapter three), it may be that the ophiuroid and ascidian abundances are a response to

physical conditions relating to freshwater input. The influence of the seasonal flow,

in particular how the large amounts of freshwater injected during the wet season

would influence the populations of the ophiuroid and ascidian is an interesting

question requiring sampling in the wet season to elucidate.

While it appears that the river influenced the abundance of the ophiuroid and

ascidian, several questions remain. For instance, why were elevated abundances of

these two species not observed at T3, which was also adjacent to a river mouth? It

may be that the local topography at T3 prevented an observable effect of the river on

these species (see discussion below). Alternatively, the high abundance of the

ophiuroid in the eastern portion of the survey may relate to habitat availability. At

low tide when sampling occurred, the majority of ophiuroids were hidden within

small openings in the reef platform, generally only with few arms


Figure 20: A species of brittle star (ophiuroid) was highly abundance along T4 with up to 80 m-1. Note the association of brittle stars with small openings in the reef, with many individuals less than half

emergent.


(a)

(b)

Figure 21: Aerial photograph of: (a) the study region demonstrating the input of sediment into the coastal zone, particularly at the mouth of the River Quelan and eddy at headland east of study area

suggesting westerly current; (b) the reef platform showing locations of sampling points (T1 T6, west east). Arrow denotes possible sediment in region of T4 and T5.


protruding (see Figure 20). Hiding at low tide may have been a response to physical

stress, with holes providing cool dark area with more water than the surrounding reef.

Alternatively the use of holes at low tide may have been a predator-avoidance

mechanism, although no obvious predators, such as wading birds, were observed in

the study. The presence of microhabitats for ophiuroid refuge may have allowed the

species to persist east of T4, while they were excluded from the T1 T3 as a result of

exposure at low tide and hence greater physical stress and predation.

The abundance of the two species in the eastern portion of the survey may also

be explained by the influence of the village of Salihasan which may have contributed

to nutrient and organic matter elevation as a result of waste disposal. This does not

explain the most marked increases in abundance being evident at the river mouth at

T4, rather than T6, suggesting that the river and sheltering in the eastern region are

more influential factors. This is supported by the higher diversity of species in

general in the eastern region, which may be a response to more sheltered conditions

(e.g. Coates, 1998). It is also unclear whether the very high abundances of the two

species observed in the eastern region is a naturally occurring or anthropogenically

induced phenomenon.

In contrast to the distinct spatial pattern of the ophiuroid and ascidian in the

survey, there was no pattern of significant differences in the overall sessile

community between river/village transects and isolated transects. For instance, the

river transect T4 was significantly different than the isolated transects T1 and T2;

however, another river transect, T5, which was directly adjacent to T4 and positioned

at the same river mouth, was not significantly different from any other transect.

Similarly, T6 adjacent to Salihasan was only significantly different from T2, and not

T1 or any other transect. There was no evidence of nutrient enrichment along the

river transects, such as a prevalence of green algal growth or loss of macrovegetation

as the result of shading by rapidly proliferating epibionts (Grall & Chauvaud, 2002).

This lack of a river-nutrient effect is perhaps surprising given the level of

deforestation that has occurred in East Timor (Sandlund et al., 2001; Bouma &

Kobryn, 2004) and rural activities that take place in the catchment surrounding

Betano (pers. obs., see also chapter three). However, the tropical soils in East Timor

have inherently low fertility as a result of rapid decomposition of organic matter,

which may limit natural nutrient supplies (Anderson & Deutsch, 2001). A companion

study (Lampharski, 2004) confirmed that nutrient levels in rivers of the region were


below detectable limits and chlorophyll a concentration minimal, indicating that

nutrient enrichment of these rivers is not prevalent. Hence impacts on marine biota

would not be expected in the absence of significant anthropogenic enhancement of

nutrient inputs to the coastal environment.

The lack of nutrient enrichment resulting from rivers is further evidenced by

the very low benthic microalgae biomass (as chlorophyll a) of sediments. A positive

relationship between increased benthic algal biomass and increased nutrient loadings

to coastal waters has been established (Grall & Chauvaud, 2002). It could be

expected that, if rivers on the south coast of East Timor were resulting in nutrient

enrichment, this would be observable as elevated benthic algal biomass. This study

demonstrated that chlorophyll a concentrations were very low and that there was a

very low ratio of chlorophyll to pheaophytin suggesting a large amount of degradation

of intact chlorophyll. While this may have resulted from responses of benthic algae to

environmental conditions (e.g. Mitbavkar & Anil, 2004) or the treatment of samples

being suboptimal, it suggests that the sedimentary environment does not support high

benthic microalgae biomass. Benthic microalgae biomass is generally low in tropical

sediments, usually <5 g chl a.g-1 dry weight as reported in a number of studies and

summarised by Alongi (1989). While not directly comparable, this study sampled

<50 g chl a.m-1 which is low even for tropical sediments and may be indicative of

the oligotrophic environment.

On the above basis, it would appear that the null hypothesis of no species

differences as a result of point source anthropogenic influences must be accepted (but

see caveat below) and apparent differences in overall species composition (ignoring

the possible species specific responses of the ascidian and ophiuroid to the river)

along the reef must be explained in alternative ways.

The first possible explanation for the observed variation in species

composition is that the rock platform was spatially variable in terms of topography.

The physical shape of the reef, in terms of the slope and the presence of rock pools

and mounds of rock was variable between sites and is likely to have had a pronounced

influence on species composition (e.g. Schoch & Dethier, 1996). Along T4 T6 the

reef platform was relatively flat while the slope along T1 T2 was slightly more

pronounced (pers. obs.). At T3 the reef platform was broken by the presence of rock

pools which contained more water than surrounding areas at low tide. Consequently,


this was the only transect to contain coral and had even had populations of small fish

(pers. obs.).

The likely influence of variable reef topography on species composition is

reinforced by the observation of different species composition at differing distances

from the shore for the survey area as a whole. As could be expected, the seaward

slope of the reef led to decreasing aerial exposure at low tide with distance from the

shore, which led to distinctly different species dominating each distance. Intertidal

zonation of species, largely as a result of physical stress and associated differences in

biological and indirect effects varying with height on the shore, has been widely

studied and acknowledged for both rocky shores and soft sediment environments

(Paine, 1966; Dayton, 1971; Connell, 1972; Peterson, 1991; Menge & Branch, 2001,

and many others).

The relative influence of physiological stress and biological factors such as

competition and predation on the observed effect of tidal exposure on species

composition is hard to determine from this study. The brown alga was generally

restricted to distances greater than 20m, most likely as a result of greater tidal

exposure and hence desiccation stress excluding the species from dominating the

upper shore. Conversely, the Caulerpa sp. characteristic of 0m, and to a lesser extent

the Padina sp. at 10m, appeared able to tolerate greater tidal exposure and hence were

most abundant in these upper shore zones. Alternatively, these species may be

excluded from regions further from shore due to the abundance of the brown alga

overstory, which, for example, is likely to lead to light limitation. While the

processes cannot be determined, this study demonstrates that tidal exposure is a

significant factor shaping the community of this reef and suggests that the different

topography of the reef may be one factor contributing to significant differences in

species composition along the study area.

In contrast to sessile species, the influence of physiological stress at tidal

exposure was readily evident for the ophiuroid species. The ophiuroid was only

sampled at 10m or greater from the shore, and those individuals that were almost

exposed at low tide showed significant signs of stress such as foaming and arms

floating at the waters surface (pers. obs.). This may have been a result of high

temperatures and/or low oxygen levels in very shallow water at low tide and again

demonstrates the influence of tidal exposure on species distribution across the reef.


A second possible explanation for the spatial variation of species independent

of point sources of contamination is the varying degree of wave exposure experienced

at different sites. The degree of wave exposure has been found to be the most

important factor shaping macroalgal assemblages in another study investigating a

tropical intertidal region in a developing nation (Schils et al., 2001). In this study, T1

and T2 occurred at a narrow section of the reef and hence were more exposed to wave

action, perhaps leading to the dominance of the brown alga which is likely to be better

able to withstand wave action than more delicate species. Other transects were taken

across broader sections of the reef, so that the nearshore distance were more protected

from wave action, perhaps allowing other species to persist with the brown alga

dominating at further distances where wave action was more influential.

Whether a result of reef topography or wave exposure, small-scale variation in

the composition of the intertidal community was strongly evident and has

implications for extrapolating the results of this study to represent the entire 13km

reef section. Schoch and Dethier (1996) outline a technique whereby species

composition determined from the few transects in this study could be scaled up to

represent the species composition of the entire stretch of intertidal reef, allowing for

small-scale variations in topography or wave exposure. While this is considered

useful for aiding management of anthropogenic impacts on the intertidal zone, more

detailed analyses are required than were practical in this study.

The above discussion and the assumption of no apparent anthropogenic impact

on intertidal species biota must be read in light of the following caveat. The design of

this study was based on the assumption that anthropogenic influences on the biota of

the reef would emanate from point sources and hence would be detectable by

sampling at the presumed location of these point sources. There are several reasons

why this may be invalid. Firstly, the degree to which anthropogenic contaminates are

dispersed away from their source cannot be determined without knowledge of local

oceanography. There is currently no information regarding currents in the region, or

even detailed local climatic information such as wind speeds and directions (since

there is no infrastructure to enable such measurements). The dispersal of

contaminants along the reef will be determined by nearshore currents, the influence of

which may confound the interpretation of this study, which was based on

contamination only being observed locally at its source. For instance, it may be that

elevated nutrients or sediments, for example, are released from the river between T4


and T5 and mixed and dispersed in coastal water adjacent to the reef in such a way

that all transects studied will be equally affected by them, or alternatively, only

transects in one direction. Dispersal of sediments and organic matter east of T4/T5

may explain the occurrence of the ophiuroid and ascidian absent from T1 T3.

Interestingly, observations of aerial photographs of the region appear to suggest a

prevailing east to west current and movement of sediment, with the presence of a

headland to the east of T6 perhaps minimising dispersal of sediments away from the

eastern portion of the survey (Figure 21, see also Chapter Three).

Another factor which may confound interpretation of this study is chronic,

rather than point sources, of contamination due to anthropogenic activity. For

instance it may be that increased nutrients in the catchment are transported to the

nearshore zone in groundwater and hence have a spatially-independent impact on reef

biota. Chronic impacts on the reef biota which occurred prior to this study cannot be

inferred, highlighting the necessity for baseline data and ongoing monitoring to detect

anthropogenic impacts.

4.4.1. Conclusions

The most important outcome of this study is the provision of a baseline data

set of species composition on the intertidal reef platform, gathered using relatively

simple survey techniques. Such information has never been gathered previously and

will be essential for assessing the impacts of development in the region. Currently it

would appear that anthropogenic activities on the intertidal biota are minimal and

differences in species composition along the reef are largely driven by physical

differences resulting from spatially variable reef topography and wave exposure.

Despite the apparent lack of distinct impacts on biota from land-based activities, the

strong influence of fluvial flux on the nearshore environment has been established (in

Chapter Three) and there was some evidence of species-specific responses to riverine

sources in this phase of the study. These findings suggest that there is a significant

potential for land-based developments to impact the biota of the nearshore coastal

environment. Management of these impacts will be dependent on using this study as

a basis for further investigating local oceanography and other influences on the

intertidal biota of the region.


5. Discussion

In this study a preliminary step towards redressing the paucity of knowledge

about East Timor s marine environment has been taken. In assessing the marine

environment on the south coast for the first time the strong fluvial link between the

terrestrial and nearshore marine realm has been demonstrated. While the nearshore

zone appears to be in relatively pristine condition, as has been assumed for much of

Timor s marine environment (e.g. Sandlund et al., 2001), the strong connection via

fluvial flux suggests a significant capacity for impacts to result from land-based

activities. The baseline data from this study may be useful in assessing impacts of

development in the region; however, more detailed investigation of a variety of

marine habitats is required for informed management of development.

Once the quality of the environment starts to decline it is extremely hard to

control or return to the pristine condition and it may be advantageous to identify

potential impacts from development before they occur so that research and

management efforts can be focused on minimising impacts (Dubinsky & Stambler,

1996; Morrison & Delaney, 1996). A variety of developments have the potential to

occur on East Timor s south coast with foreseeable impacts on the marine

environment and local population of Betano. The potential impacts resulting from

increased sedimentation on the intertidal reef studied, as well as coral communities

offshore, has already been largely discussed in the preceding chapters. In a similar

way, land-based activities altering the fluvial flux of nutrients and freshwater has the

capacity to impact the biota of the nearshore zone in a variety of ways. The potential

for developments in the region to alter fluvial flux should be considered in assessing

the sustainability of any developments.

Physical alteration of the coastal environment around Betano also has the

potential to occur. In particular, facilities to allow vessel activity are needed to

facilitate trade links in the region, and options to expedite this are potentially being

explored by the Government of East Timor. The intertidal reef platform may

represent a particularly suitable area for jetty construction, with hard substrate and

deep water directly offshore of the reef. Such activity could interrupt and alter the

apparently substantial longshore transport of terrigenous sediment and thereby

completely alter the nearshore environment.


While unlikely, there is also the potential for oil spills to occur in the region,

particularly if current exploration activities result in significant extraction of oil. An

index by Nansingh and Jurawan (1999) suggests that Betano s intertidal wave-cut reef

platform is likely to be the least sensitive of marine ecosystems to the impacts of oils

spills. Given the dependence of coastal populations on marine resources and the

economic value of these resources in pristine condition, such through promoting

tourism, oil spills should be considered a threat to the nearshore zone and oil

extraction managed accordingly.

Another potential impact not considered in this study is the capacity for human

harvest to impact the biota of the intertidal reef, as well as other marine habitats.

Anecdotal evidence and personal observation suggest that large mollusc species are

harvested from Betano s intertidal reef by subsistence fishermen, which may result in

significant impacts on community composition (e.g. de Boer & Prins, 2002). As

populations grow and demand on nearshore resources increases such impacts are

likely to become more prevalent (e.g. Thia-Eng, 1999). In such cases, controlling

harvest levels or introducing protected areas may be necessary. Marine protected

areas may benefit species conservation, as well as provide social benefits such as

attracting tourism and providing alternative livelihoods to subsistence living (e.g.

Kuhlmann, 2002).

An increase in utilisation of the intertidal reef, either due to population

increases resulting in greater demand for resources obtained from the reef, or due to

tourism development in the region, also has the potential for impacts due to direct

damage. In an experimental study of the effects of trampling on a temperate intertidal

reef, Brown and Taylor (1999) found that many species were vulnerable to low levels

of trampling largely as a result of habitat damage. Impacts on coral survivorship have

also be observed as a result of trampling by tourists (e.g. Rodgers & Cox, 2003).

Such observations suggest that increased utilisation of the intertidal reef near Betano

from the current low levels may result in impacts from direct damage. For instance,

the abundant brittle stars on the reef are highly susceptible to trampling at low tide.

Brown and Taylor (1999) suggest that avoidance of such impacts may only be

possible by completely excluding human activity from the intertidal, which, given the

dependence on the reef for subsistence, is unlikely to be feasible around Betano.

Current vessel activity around Betano is minimal. The only craft observed in

the region consisted of very small dug-out canoes used by subsistence fishermen, with


very few being motorised. As development occurs in the region increases in vessel

activity are highly likely, particularly if infrastructure to allow access to the coast,

such as a marina or jetty, are constructed. While this will benefit the region

economically, allowing fishing catch caught offshore to be bought ashore directly,

rather than taken by sea to Dili, there is the potential for impacts on the marine

environment as a direct result of vessel traffic. For instance, vessel activity is likely

to increase waste discharge in the nearshore zone (Morrison & Delaney, 1996), result

in physical damage (e.g. Hawkins & Roberts, 1994), and lead to the introduction of

non-indigenous species (Carlton, 1987; Carlton, 1989; Carlton & Geller, 1993;

Carlton, 1996; Lavoie et al., 1999).

5.1. Conclusions

Given the likelihood of development occurring around Betano as part of East

Timor s attempts to recover economically, there are several ways the current study

could be continued and expanded in order to obtain data essential for assessing and

managing the impacts of development on the marine environment. Focus on

assessing intertidal biota and impacts from land-based activities should be expanded

to include subtidal habitats and other potential sources of impact. Currently,

conducting studies of subtidal habitats in the region represents a significant logistical

and safety challenge. The region lacks the infrastructure required to allow SCUBA

diving operations, such as diving vessel access to the shore and reliable power for

maintaining equipment, and there are safety concerns related to the distance to

decompression facilities and the presence of crocodiles in the nearshore zone.

Ironically, the studies necessary to document the impacts of development on the

marine environment in this region may only become possible once development has

occurred. This negates the usefulness of the before-impact component of surveying

using BACIP (before-after, control-impacted paired) monitoring, which is considered

essential for assessing impacts on the marine environment (e.g. Warnken & Buckley,

2000). Hence, despite the challenges, further investigation of East Timor s marine

environment should continue as a matter of priority before significant development

and alteration occurs. Such investigation, begun by this study, will allow accurate

assessment and informed management of the impacts of development on the marine

environment, which is a significant resource for the nation if kept in pristine condition.


5.2. Recommendations

The preliminary nature of this study means that there are several ways the

study should be extended. Some recommendations for extending the study, as well as

some general recommendations regarding the marine environment and development

in East Timor, are as follows:

5.2.1. Investigate taxonomy of intertidal reef biota

Samples collected from Betano s intertidal reef have yet to arrive in Australia

and be subjected to through taxonomic analysis. Samples should be identified to the

lowest taxonomic unit possible in order to name species in the baseline data set so that

future comparisons can be easily made. Also, the identity of species on the intertidal

reef may be of interest in a biogeographic investigation, with questions regarding the

likely affinity of species, given that East Timor is thought to be an uplifted portion of

the Australian plate. Whether the species sampled show close relation to Australian

or surrounding Indonesian intertidal taxa remains to be determined.

5.2.2. Temporally and spatially extend current surveying

The current study was necessarily limited spatial and temporally. Further

research should extend the survey of intertidal biota by examining the whole stretch

of intertidal reef platform east of Betano. As demonstrated in this study there is the

potential for species composition to vary significantly over small spatial scales in

response to a variety of factors.

The strong seasonal influence of fluvial flux will also be better elucidated by

sampling over a longer temporal scale, with sampling in the wet season when water

flow is strongest being particularly important.

It would also be advantageous if other regions along the south coast could be

surveyed to document variation in habitat types and species composition. In

particular, surveying in the current study could be compared to surveying of similar

habitats near to the main city on the south coast, Suai, where impacts from

development are already likely to be more prevalent.

5.2.3. Survey other nearshore habitats

This study has been restricted to the intertidal and a variety of other habitats,

particularly in the subtidal, remain to be documented. This study suggests that

significant coral communities exist offshore from Betano. Corals are particularly


susceptible to stress and are likely to be good indicators of anthropogenic impacts on

the nearshore zone (e.g. Keough & Quinn, 1991).

Sediment sampling within rivers and offshore habitats may also better

elucidate the fate and flux of terrigenous sediments in the nearshore marine

environment. Direct measurement of sediments in rivers will provide an important

baseline of the characteristics of sediment supplied to the coast (e.g. Neil et al., 2002).

Currently it would appear that fine terrigenous material in particular is lost to the

offshore zone. Anecdotal evidence suggests that offshore from Betano the benthos

changes to a muddy substrate, suggesting that fine material may be settling out of

suspension under lower energy conditions in deeper water. The degree to which

terrigenous sediments are retained or loss will be a significant factor determining the

impact of anthropogenically increased sediment flux on the nearshore environment.

Sediment cores taken in areas subject to lower energy conditions and longer

depositional history, such as offshore muds, may allow for detection of temporal

changes in fluvial sediment flux. Documentation of anthropogenically induced

changes in sediment flux was one of the aims of this study, but was unachievable due

to the high energy environment from which cores could be obtained.

5.2.4. Investigate regional oceanography

Many of the observations in this study have been made on the basis of

informed assumptions regarding local oceanography. There is currently no

information available on local oceanography which will be a major determinant of

impacts from development, such as transport and dispersal of pollutants (e.g. Torres et

al., 2001). Knowledge of local oceanography will be essential for assessing the

impacts of development on the marine environment (e.g. Morrison & Delaney, 1996).

5.2.5. Planned monitoring of susceptible areas

If significant developments are planned in the region, study should focus on

monitoring of areas identified as most susceptible to impacts using a BACIP (before-

after, control-impacted paired) monitoring program (Warnken & Buckley, 2000). A

preliminary step has been taken towards providing the before, or control, components

of this program for Betano s intertidal reef. Further study focusing on a variety of

habitats may allow for early indication of impacts soon enough for management

interventions to take place (Morrison & Delaney, 1996; Thia-Eng, 1999)


5.2.6. Public involvement in development and environmental protection

Independent of the scientific approach to assessing and monitoring the marine

environment advocated in this study, the local population should also be involved in

achieving sustainable development that does not impact the marine environment.

Such public participation has been recommended as an effective way to solve

environmental and development issues (Luttinger, 1997; Yap, 2000; Elliott et al.,

2001; Pires, 2001; Tran et al., 2002). While few people in East Timor have received

structured education, an understanding and care for the environment is ingrained in

many of the nation s cultures (e.g. Soares, 2001). Without the agreement and

involvement of local people, any attempts to protect the marine environment from

developmental impacts are unlikely to be unsuccessful.

5.2.7. Restore degraded habitats

While the focus of this study has been the prevention of impacts on the marine

environment from development there is considerable potential to apply restoration

techniques to coastal habitats which have already been degraded (Yap, 2000).

Restoration may become important if development in East Timor is allowed to have

significant impacts. There is evidence of the long history of impacts on the coastal

environment around Dili on the north coast being addressed, such as restoration of

mangrove forests west of capital (pers. obs.). While such attempts are necessary in

degraded areas, focus should remain on preventing impacts from occurring in the

pristine environment of East Timor s south coast, since even with restoration, the

impacts of development will be hard to reverse once they have occurred.


6. References Alongi, D.M. (1989) The role of tropical soft-bottom benthic communities in tropical

mangrove and coral reef ecosystems. Review of Aquatic Sciences, 1, 234-280. Alongi, D.M. (1990) The ecology of tropical soft bottom benthic ecosystems.

Oceanography & Marine Biology Annual Review, 28, 381-496. Alongi, D.M. (1998) Coastal Ecosystem Processes. CRC Press, Boca Raton, pp. 419. Anderson, R. & Deutsch, C. (2001) Sustainable development and the environment in

East Timor. Conference on Sustainable Development, Dili, East Timor, 5-31 January 2001. Timor Aid, Dili, East Timor.

Andrews, J.C. & Gentien, P. (1982) Upwelling as a source of nutrients to the Great Barrier Reef ecosystem: a solution to Darwin's question? Marine Ecology Progress Series, 8, 257.

Atkinson, M.J. (1992) Productivity of the Enewetak flats predicted from mass transfer relationships. Continental Shelf Research, 12, 799-807.

Atkinson, M.J., Falter, J.L., & Hearn, C.J. (2001) Nutrient dynamics in the Biosphere 2 coral reef mesocosm: Water velocity controls NH4 and PO4 uptake. Coral Reefs, 20, 341-346.

Barnes, D.J. & Lough, J.M. (1997) Several centuries of variation in skeletal extension, density and calcification in massive Porities colonies from the Great Barrier Reef: A proxy for seawater temperature and a background of natural variability against which to identify unnatural change. Journal of Experimental Marine Biology & Ecology, 211, 29-67.

Barnes, D.J. & Lough, J.M. (1999) Porites growth characteristics in a changed environment: Misima Island, Papua New Guinea. Coral Reefs, 18, 213-218.

Bellan, G.L. & Bellan-Santini, D.R. (2001) A review of littoral tourism, sport and leisure activities: consequences on marine flora and fauna. Aquatic Conservation-Marine and Freshwater Ecosystems, 11, 325-333.

Bouma, G.A. & Kobryn, H.T. (2004) Change in vegetation cover in East Timor, 1989-1999. Natural Resources Forum, 28, 1-12.

Brown, B.E. & Howard, L.S. (1985) Assessing the effects of "stress" on reef corals. Advances in Marine Biology, 22, 1-63.

Brown, P.J. & Taylor, R.B. (1999) Effects of trampling by humans on animals inhabiting coralline algal turf in the rocky intertidal. Journal of Experimental Marine Biology & Ecology, 235, 45-53.

Burford, M.A., Long, B.G., & Rothlisberg, P.C. (1994) Sedimentary pigments and organic carbon in relation to microalgal and benthic faunal abundance in the Gulf of Carpentaria. Marine Ecology-Progress Series, 103, 111-117.

Burgess, R.M. (2000) Characterizing and identifying toxicants in marine waters: a review of marine toxicity identification evaluations (TIEs). International Journal of Environment and Pollution, 13, 2-33.

Carleton, J.H. & Done, T.J. (1995) Quantitative video sampling of coral reef benthos: Large-scale application. Coral Reefs, 14, 35-46.

Carlton, J.T. (1987) Patterns of transoceanic marine biological invasions in the Pacific Ocean. Bulletin of Marine Science, 41, 452-465.

Carlton, J.T. (1989) Man's Role in Changing the Face of the Ocean: Biological Invasions and Implications for Conservation of Near-Shore Environments. Conservation Biology, 3, 265-273.


Carlton, J.T. (1996) Pattern, process, and prediction in marine invasion ecology. Biological Conservation, 78, 97-106.

Carlton, J.T. & Geller, J.B. (1993) Ecological roulette: The global transport of nonindigenous marine organisms. Science (Washington D C), 261, 78-82.

Carrascalao, M. (2001) Address to conference on sustainable development. Conference on Sustainable Development, Dili, East Timor, 5-31 January 2001, pp. 14-15. Timor Aid, Dili, East Timor.

Carter, R.W. (2001) Developing Sustainable Tourism in East Timor: Some insights for South East Asia. Conference on Sustainable Development in East Timor, Dili, East Timor, 5-31 January 2001, pp. 69-70. Timor Aid, Dili, East Timor.

Chao, A. (1987) Estimating the population size for capture-recapture data with unequal catchability. Biometrics, 43, 783-791.

Christie, P. & White, A.T. (1997) Trends in development of coastal area management in tropical countries: From central to community orientation. Coastal Management, 25, 155-181.

Clarke, K.R. (1993) Non-parametric multivariate analyses of changes in community structure. Australian Journal of Ecology, 18, 117-143.

Clarke, K.R. & Ainsworth, M. (1993) A method linking multivariate community structure to environmental variables. Marine Ecology-Progress Series, 92, 205-219.

Clarke, K.R. & Gorley, R.N. (2001) PRIMER v5: User Manual/Tutorial. PRIMER-E Ltd, Plymouth, UK.

Clarke, K.R. & Warwick, R.M. (1994) Change in marine communities: an approach to statistical analysis and interpretation. Natural Environmental Research Council, United Kingdom, pp. 144.

Clarke, P.J. & Kerrigan, R.A. (2000) Do forest gaps influence the population structure and species composition of mangrove stands in northern Australia? Biotropica, 32, 642-652.

Coates, M. (1998) A comparison of intertidal assemblages on exposed and sheltered tropical and temperate rocky shores. Global Ecology and Biogeography, 7, 115-124.

Colwell, R.K. (2004) EstimateS: statistical estimation of species richness and shared species from samples. Version 7. University of Connecticut. (http://purl.oclc.org/estimates

- Accessed: 22/04/2004) Colwell, R.K. & Coddington, J.A. (1994) Estimating Terrestrial Biodiversity through

Extrapolation. Philosophical Transactions: Biological Sciences, 345, 101-118. Connell, J.H. (1972) Community interactions on marine rocky intertidal shores.

Annual Review of Ecology and Systematics, 3, 169-192. Coutts, A.D.M. (1999) Hull fouling as a modern vector for marine biological

invasions: investigation of merchant vessels visiting northern Tasmania. Masters Thesis, Australian Maritime College, Launceston.

Davies, P.J., Marshall, J.F., & Hopley, D. (1985) Relationships between reef growth and sea level in the Great Barrier Reef. Proceedings of the Fifth International Coral Reef Symposium, 3, pp. 95.

Dayton, L. (1995) The killing reefs. New Scientist, 148, 14-15. Dayton, P.K. (1971) Competition, disturbance and community organisation: the

provision and subsequent utlization of space in a rocky intertidal community. Ecological Monographs, 41.

de Boer, W.F. & Prins, H.H.T. (2002) Human exploitation and benthic community structure on a tropical intertidal flat. Journal of Sea Research, 48, 225-240.

http://purl.oclc.org/estimates


de Boer, W.F., van Schie, A.M.P., Jocene, D.F., Mabote, A.B.P., & Guissamulo, A. (2001) The impact of artisanal fishery on a tropical intertidal benthic fish community. Environmental Biology of Fishes, 61, 213-229.

de Jonge, V.N., Elliott, M., & Orive, E. (2002) Causes, historical development, effects and future challenges of a common environmental problem: Eutrophication. Hydrobiologia, 475-476, 1-19.

Dethier, M.N., Graham, E.S., Cohen, S., & Tear, L.M. (1993) Visual Versus Random-Point Percent Cover Estimations - Objective Is Not Always Better. Marine Ecology-Progress Series, 96, 93-100.

DeVantier, L., Alcala, A., & Wilkinson, C. (2004) The Sulu-Sulawesi Sea: Environmental and socioeconomic status, future prognosis and ameliorative policy options. Ambio, 33, 88-97.

Done, T.J. (1992) Constancy and change in some Great Barrier Reef coral communities: 1980 - 1990. American Zoologist, 32, 655-662.

Dubinsky, Z. & Stambler, N. (1996) Marine pollution and coral reefs. Global Change Biology, 2, 511-526.

Eckman, J.E. (1996) Closing the larval loop: Linking larval ecology to the population dynamics of marine benthic invertebrates. Journal of Experimental Marine Biology & Ecology, 200, 207-237.

Edinger, E.N. & Risk, M.J. (2000) Reef classification by coral morphology predicts coral reef conservation value. Biological Conservation, 92, 1-13.

Edmunds, P.J., Aronson, R.B., Swanson, D.W., Levitan, D.R., & Precht, W.F. (1998) Photographic versus visual census techniques for the quantification of juvenile corals. Bulletin of Marine Science, 62, 937-946.

Eldredge, L.G. & Carlton, J.T. (2002) Hawaiian marine bioinvasions: a preliminary assesment. Pacific Science, 56, 211-212.

Elliott, G., Wiltshire, B., Manan, I.A., & Wismer, S. (2001) Community participation in marine protected area management: Wakatobi National Park, Sulawesi, Indonesia. Coastal Management, 29, 295-316.

Ellison, A.M. & Farnsworth, E.J. (2001). Mangrove communities. In Marine Community Ecology (ed. by M.E. Hay), pp. 423-442. Sinauer Associates, Inc., Sunderland, Massachusetts.

English, S., Wilkinson, C.R., & Baker, V. (1994). Survey manual for tropical marine resources, Australian Insititure for Marine Science, Townsville, Australia.

Epstein, N., Bak, R.P.M., & Rinkevich, B. (1999) Implementation of a small-scale "no-use zone" policy in a reef ecosystem: Eilat's reef lagoon six years later. Coral Reefs, 18, 327-332.

Evans, S.M. (1995) Domestic waste and TBT pollution in coastal areas of Ambon (Eastern Indonesia). Marine Pollution Bulletin, 30, 109-115.

Falkowski, P.G., Dubinsky, Z., Muscatine, L., & McCloskey, L. (1993) Population control in symbiotic corals: ammonium ions and organic materials maintain the density of zooxanthelle. Bioscience, 43, 606-611.

Ferrier-Pages, C., Gattuso, J.P., Dallot, S., & Jaubert, J. (2000) Effect of nutrient enrichment on growth and photosynthesis of the zooxanthellate coral Stylophora pistillata. Coral Reefs, 19, 103-113.

Field, J.G., Clarke, K.R., & Warwick, R.M. (1982) A practical strategy for analysing multispecies distribution patterns. Marine Ecology-Progress Series, 8, 37-52.

Foster, M.S., Harrold, C., & Hardin, D.D. (1991) Point vs. photo quadrat estimates of the cover of sessile marine organisms. Journal of Experimental Marine Biology & Ecology, 146, 193-203.


Fox, J.J. (2003). Tracing the path, recounting the past: historical perspectives on Timor. In Out of the ashes: destruction and reconstruction of East Timor (ed. by J.J. Fox & D.B. Soares), pp. 1-27. ANU E Press, Canberra.

Gerges, M.A. (1994) Marine pollution monitoring, assessment and control: UNEP's approach and strategy. Marine Pollution Bulletin, 28, 199-210.

Gillanders, B.M. & Kingsford, M.J. (2002). Impact of changes in flow of freshwater on estuarine and open coastal habitats and the associated organisms. In Oceanography and Marine Biology, Vol. 40, pp. 233-309. TAYLOR & FRANCIS LTD, London.

Golbuu, Y., Victor, S., Wolanski, E., & Richmond, R.H. (2003) Trapping of fine sediment in a semi-enclosed bay, Palau, Micronesia. Estuarine, Coastal and Shelf Science, 57, 941-949.

Gossling, S. (2001) The consequences of tourism for sustainable water use on a tropical island: Zanzibar, Tanzania. Journal of Environmental Management, 61, 179-191.

Grall, J. & Chauvaud, L. (2002) Marine eutrophication and benthos: the need for new approaches and concepts. Global Change Biology, 8, 813-830.

Grigg, R.W. (1995) Coral reefs in an urban embayment in Hawaii: A complex case history controlled by natural and anthropogenic stress. Coral Reefs, 14, 253-266.

Hanson, A.J. (2001) Sustainable Development - an introduction for East Timor. Conference on Sustainable Development, Dili, East Timor, 5-31 January 2001, pp. 25-27. Timor Aid, Dili, East Timor.

Hantoro, W.S., Nganro, N., Shofiyah, S., Narulita, I., & Sofjan, J. (1997) Recent climate variation signals from corals in Timor, Indonesia. Quaternary International, 37, 81-87.

Hawkins, J.P. & Roberts, C.M. (1994) The Growth of Coastal Tourism in the Red-Sea - Present and Future-Effects on Coral-Reefs. Ambio, 23, 503-508.

Hearn, C.J., Atkinson, M.J., & Falter, J.L. (2001) A physical derivation of nutrient-uptake rates in coral reefs: Effects of roughness and waves. Coral Reefs, 20, 347-356.

Hewitt, C.L. (2002) Distribution and biodiversity of Australian tropical marine bioinvasions. Pacific Science, 56, 213-222.

Hill, H. & Saldanha, J.M., eds. (2001) East Timor: development challenges for the world's newest nation. Asia Pacific Press, Australian National University, Canberra, Australia.

Hinrichsen, D. (1998) Coastal waters of the world: trends, threats, and strategies. Island Press, Washington, D.C., pp. 275.

Hutchinson, N. & Williams, G.A. (2001) Spatio-temporal variation in recruitment on a seasonal, tropical rocky shore: the importance of local versus non-local processes. Marine Ecology-Progress Series, 215, 57-68.

Isoun, E., Fletcher, C., Frazer, N., & Gradie, J. (2003) Multi-spectral mapping of reef bathymetry and coral cover; Kailua Bay, Hawaii. Coral Reefs, 22, 68-82.

Jaap, W.C. & McField, M.D. (2001) Video sampling for monitoring coral reef benthos. Bulletin of the Biological Society of Washington, 10, 269-273.

Keough, M.J. & Quinn, G.P. (1991) Causality and the choice of measurements for detecting human impacts in marine environments. Australian Journal of Marine & Freshwater Research, 42, 539 554.


Kinsey, D.W. (1977) Seasonality and zonation in coral reef productivity and calcification. Proccesings of the 3rd International Coral Reef Symposium, 2, pp. 383-388.

Knowlton, N. & Jackson, J.B.C. (2001). The Ecology of Coral Reefs. In Marine Community Ecology (ed. by M.D. Bertness, S.D. Gaines & M.E. Hay), pp. 395-422. Sinauer Associates, Inc., Sunderland, Massachusetts.

Kruskal, J.B. (1964) Multidimensional scaling by optimizing goodness of fit to a nonmetric hypothesis. Psychometrika, 29, 1-27.

Kuhlmann, K.J. (2002) Evaluations of marine reserves as basis to develop alternative livelihoods in coastal areas of the Philippines. Aquaculture International, 10, 527-549.

Kvernevik, T.-I., Akhir, M.Z.M., & Studholme, J. (2002) A low-cost procedure for automatic seafloor mapping, with particular reference to coral reef conservation in developing nations. Hydrobiologia, 474, 67-79.

Lampharski, H. (2004). Honours thesis, University of Western Australia, Perth, Australia.

Lavering, I.H. (1993) Quaternary and modern environments of the Van Diemen Rise, Timor Sea, and potential effects of additional petroleum exploration activity. Bmr (Bureau of Mineral Resources) Journal of Australian Geology & Geophysics, 13, 281-292.

Lavoie, D.M., Smith, L.D., & Ruiz, G.M. (1999) The potential for intracoastal transfer of non-indigenous species in the ballast water of ships. Estuarine Coastal & Shelf Science, 48, 551-564.

Lewin, R. (1986) Supply-side ecology. Science (Washington D C), 234, 25-27. Li, D.J. & Daler, D. (2004) Ocean pollution from land-based sources: East China Sea,

China. Ambio, 33, 107-113. Luttinger, N. (1997) Community-based coral reef conservation in the Bay Islands of

Honduras. Ocean & Coastal Management, 36, 11-22. Macaulay, J. (2003) Timor Leste: Newest and poorest of Asian nations. Geography,

88, 40-46. Mann, K.H. (2000) Ecology of Coastal Waters With Implications for Management,

2nd edn. Blackwell Science, Inc., Malden, USA, pp. 406. McClanahan, T.R. (2002) The near future of coral reefs. Environmental Conservation,

29, 460-483. McLaughlin, C.J., Smith, C.A., Buddemeier, R.W., Bartley, J.D., & Maxwell, B.A.

(2003) Rivers, runoff, and reefs. Global and Planetary Change, 39, 191-199. McManus, J.W., Menez, L.A.B., Kesner-Reyes, K.N., Vergara, S.G., & Ablan, S.M.C.

(2000) Coral reef fishing and coral-algal phase shifts: implications for global reef status. ICES Journal of Marine Science, 57, 572-578.

Meese, R.J. & Tomich, P.A. (1992) Dots on the Rocks - a Comparison of Percent Cover Estimation Methods. Journal of Experimental Marine Biology and Ecology, 165, 59-73.

Menge, B.A. & Branch, G.M. (2001). Rocky Intertidal communities. In Marine Community Ecology (ed. by M.D. Bertness, S.D. Gaines & M.E. Hay), pp. 221-251. Sinauer Associates, Inc., Sunderland, Massachusetts.

Milliman, J.D., Farnsworth, K.L., & Albertin, C.S. (1999) Flux and fate of fluvial sediments leaving large islands in the East Indies. Journal of Sea Research, 41, 97-107.


Mitbavkar, S. & Anil, A.C. (2004) Vertical migratory rhythms of benthic diatoms in a tropical intertidal sand flat: influence of irradiance and tides. Marine Biology, 145, 9-20.

Morrison, R.J. & Delaney, J.R. (1996) Marine pollution in the Arafura and Timor Seas. Marine Pollution Bulletin, 32, 327-334.

Mounsey, R. (2001) Economic & Envionmental Effects of Offshore Fishing Activities. Conference on Sustainable Development in East Timor, Dili, East Timor, 5-31 January 2001, pp. 63-64. Timor Aid, Dili, East Timor.

Mumby, P., Chisholm, J.R.M., Clark, C.D., Hedley, J.D., & Jaubert, J. (2001) Spectrographic imaging: A bird's-eye view of the health of coral reefs. Nature, 413, 36.

Mumby, P., Harborne, J., & Harborne, A. (1999) Development of a systematic classification scheme of marine habitats to facilitate regional management and mapping of Caribbean coral reefs. Biological Conservation, 88, 155-163.

Mumby, P.J., Edwards, A.J., Arias-Gonzalez, J.E., Lindeman, K.C., Blackwell, P.G., Gall, A., Gorczynska, M.I., Harborne, A.R., Pescod, C.L., Renken, H., Wabnitz, C.C.C., & Llewellyn, G. (2004) Mangroves enhance the biomass of coral reef fish communities in the Caribbean. Nature, 427, 533-536.

Mumby, P.J., Green, E.P., Edwards, C.D.C., & A, J. (1998) Digital analysis of multispectral airborne imagery of coral reefs. Coral Reefs, 17, 59-69.

Muscatine, L. & Kaplan, I.R. (1994) Resource partitioning by reef corals as determined from stable isotope composition II: delta-15N of zooxanthellae and animal tissue versus depth. Pacific Science, 48, 304-312.

Muscatine, L., Porter, J.W., & Kaplan, I.R. (1989) Resource Partitioning by Reef Corals as Determined from Stable Isotope Composition I. Delta Carbon-13-Labelled of Zooxanthellae and Animal Tissue Vs Depth. Marine Biology (Berlin), 100, 185-194.

Nansingh, P. & Jurawan, S. (1999) Environmental sensitivity of a tropical coastline (Trinidad, West Indies) to oil spills. Spill Science & Technology Bulletin, 5, 161-172.

Neil, D.T., Orpin, A.R., Ridd, E.V., & Yu, B.F. (2002) Sediment yield and impacts from river catchments to the Great Barrier Reef lagoon. Marine and Freshwater Research, 53, 733-752.

Nemeth, R.S. & Nowlis, J.S. (2001) Monitoring the effects of land development on the near-shore reef environment of St. Thomas, USVI. Bulletin of Marine Science, 69, 759-775.

Nilsson, H.C. (1999) Effects of hypoxia and organic enrichment on growth of the brittle stars Amphiura filiformis (O.F. Muller) and Amphiura chiajei Forbes. Journal of Experimental Marine Biology and Ecology, 237, 11-30.

Ninio, R. & Meekan, M.G. (2002) Spatial patterns in benthic communities and the dynamics of a mosaic ecosystem on the Great Barrier Reef, Australia. Coral Reefs, 21, 95-103.

Nybakken, J.W. (2001) Marine Biology: an ecological approach, 5th edn. Benjamin Cummings, San Francisco, pp. 516.

Owens, N.J.P. (1987) Natural variations in 15N in the marine environment. Advances in Marine Biology, 24, 389-451.

Paine, R.T. (1966) Food web complexity and species diversity. American Naturalist, 100, 65-75.

Parsons, T.R., Maita, Y., & Lalli, C.M. (1984) A manual of chemical and biological methods for seawater anaylsis. Pergamon Press, New York, pp. 173.


Paulay, G., Kirkendale, L., Lambert, G., & Meyer, C. (2002) Anthropogenic biotic interchange in a coral reef ecosystem: A case study from Guam. Pacific Science, 56, 403-422.

Pawlik, J.R. (1992) Chemical Ecology of the Settlement of Benthic Marine-Invertebrates. Oceanography and Marine Biology, 30, 273-335.

Peterson, C.H. (1991) Intertidal zonation of marine invertebrates in sand and mud. American Scientist, 79, 236-240.

Pires, E. (2001) Sustainable Development in East Timor. Conference on Sustainable Development in East Timor, Dili, East Timor, 5-31 January 2001, pp. 22-24. Timor Aid, Dili, East Timor.

Pulfrich, A., Parkins, C.A., Branch, G.M., Bustamante, R.H., & Velasquez, C.R. (2003) The effects of sediment deposits from Namibian diamond mines on intertidal and subtidal reefs and rock lobster populations. Aquatic Conservation, 13, 257-278.

Rasband, W. (2004) Image J 1.32j. National Institute of Health, USA. (http://rsb.info.nih.gov/ij/

- Accessed: 4/8/2004) Rasheed, M., Badran, M.I., Richter, C., & Huettel, M. (2002) Effect of reef

framework and bottom sediment on nutrient enrichment in a coral reef of the Gulf of Aqaba, Red Sea. Marine Ecology-Progress Series, 239, 277-285.

Raven, P.H., Evert, R.F., & Eichhorn, S.E. (1992) Biology of Plants, 5th edn. Worth Publishers, New York, USA, pp. 791.

Riaux-Gobin, C., Vetion, G., Neveux, J., & Duchene, J.-C. (1999) Microphytobenthos and phytoplankton in Banyuls bay (Gulf of Lions): Standing stocks and hydroclimatic factors. Vie et Milieu, 48, 1-13.

Richmond, R.H. (1993) Coral reefs: present problems and future concerns resulting from anthropogenic disturbance. American Zoologist, 33.

Riegl, B., Korrubel, J.L., & Martin, C. (2001) Mapping and monitoring of coral communities and their spatial patterns using a surface-based video method from a vessel. Bulletin of Marine Science, 69, 869-880.

Rinkevich, B. (1995) Restoration strategies for coral reefs damaged by recreational activities: The use of sexual and asexual recruits. Restoration Ecology, 3, 241-251.

Rodgers, K.S. & Cox, E.F. (2003) The effects of trampling on Hawaiian corals along a gradient of human use. Biological Conservation, 112, 383-389.

Roelfsema, C.M., Phinn, S.R., & Dennison, W.C. (2002) Spatial distribution of benthic microalgae on coral reefs determined by remote sensing. Coral Reefs, 21, 264-274.

Ronnback, P. (1999) The ecological basis for economic value of seafood production supported by mangrove ecosystems. Ecological Economics, 29, 235-252.

Rosenfeld, M., Bresler, V., & Abelson, A. (1999) Sediment as a possible source of food for corals. Ecology Letters, 2, 345-348.

Rougerie, F., Fagerstrom, J.A., & Andrie, C. (1992) Geothermal Endoupwelling - a Solution to the Reef Nutrient Paradox. Continental Shelf Research, 12, 785-798.

Rouphael, A.B. & Inglis, G.J. (1997) Impacts of recreational scuba diving at sites with different reef topographies. Biological Conservation, 82, 329-336.

Sammarco, P.W., Risk, M.J., Schwarcz, H.P., & Heikoop, J.M. (1999) Cross-continental shelf trends in coral delta N-15 on the Great Barrier Reef: further consideration of the reef nutrient paradox. Marine Ecology-Progress Series, 180, 131-138.

http://rsb.info.nih.gov/ij/


Samways, M.J. & Hatton, M.J. (2001) An appraisal of two coral reef rapid monitoring manuals for gathering baseline data. Bulletin of Marine Science, 69, 471-485.

Sandlund, O.T., Bryceson, I., de Carvalho, D., Rio, N., da Silva, J., & Silva, M.I. (2001). Assessing Environmental Needs and Priorities in East Timor: Issues and Priorities. Final Report, UNDP, Trondheim.

Schils, T., De Clerck, O., Leliaert, F., Bolton, J.J., & Coppejans, E. (2001) The change in macroalgal assemblages through the Saldanha Bay/Langebaan Lagoon ecosystem (South Africa). Botanica Marina, 44, 295-305.

Schoch, G.C. & Dethier, M.N. (1996) Scaling up: The statistical linkage between organismal abundance and geomorphology on rocky intertidal shorelines. Journal of Experimental Marine Biology and Ecology, 201, 37-72.

Segal, B. & Castro, C.B. (2001) A proposed method for coral cover assessment: A case study in Abrolhos, Brazil. Bulletin of Marine Science, 69, 487-496.

Shannon, C.E. & Weaver, W. (1949) The Mathematical Theory of Communication. University of Illinois Press, Urbana, pp. 117pp.

Shepard, R.N. (1962) The analysis of proximities: multidimensional scaling with an unknown disease function. Psychometrika, 27, 125-140.

Smith, S.V. (1978) Coral-reef area and the contributions of reefs to processes and resources of the world's oceans. Nature (London), 273, 225-226.

Soares, D.B. (2001) East Timor: Perceptions of Culture and Environment. Conference on Sustainable Development in East Timor, Dili, East Timor, 5-31 January 2001, pp. 18-21. Timor Aid, Dili, East Timor.

Sousa, W.P. (2001). Natural disturbance and the dynamics of marine benthic communities. In Marine Community Ecology (ed. by M.E. Hay), pp. 85-130. Sinauer Associates, Sunderland, Massachsetts.

Sullivan, K.M. & Chiappone, M. (1993) Hierarchical Methods and Sampling Design for Conservation Monitoring of Tropical Marine Hard Bottom Communities. Aquatic Conservation-Marine and Freshwater Ecosystems, 3, 169-187.

Thia-Eng, C. (1999) Marine pollution prevention and management in the East Asian Seas: A paradigm shift in concept, approach and methodology. Marine Pollution Bulletin, 39, 80-88.

Thorne, R.S.J., Williams, W.P., & Cao, Y. (1999) The influence of data transformations on biological monitoring studies using macroinvertebrates. Water Research, 33, 343-350.

Torres, R., Chiappone, M., Geraldes, F., Rodriguez, Y., & Vega, M. (2001) Sedimentation as an important environmental influence on Dominican Republic reefs. Bulletin of Marine Science, 69, 805-818.

Tran, K.C., Euan, J., & Isla, M.L. (2002) Public perception of development issues: impact of water pollution on a small coastal community. Ocean & Coastal Management, 45, 405-420.

Tribble, G.W., Atkinson, M.J., Sansone, F.J., & Smith, S.V. (1994) Reef Metabolism and Endo-Upwelling in Perspective. Coral Reefs, 13, 199-201.

Underwood, A.J. & Keough, M.J. (2001). Supply-Side Ecology: The nature and consequences of variations in recruitment of intertidal organisms. In Marine Community Ecology (ed. by M.E. Hay), pp. 183-200. Sinauer Associates, Sunderland, Massachsetts.

Vernon, J.E.N. (1995) Corals in space and time. UNSW Press, Sydney, NSW, Australia.

Walling, D.E. & Fang, D. (2003) Recent trends in the suspended sediment loads of the world's rivers. Global and Planetary Change, 39, 111-126.


Warnken, J. & Buckley, R. (2000) Monitoring diffuse impacts: Australian tourism developments. Environmental Management, 25, 453-461.

Wilkinson, C.R. (1996) Global change and coral reefs: impacts on reefs, economies and human cultures. Global Change Biology, 2, 547 588.

Wilson, S.G., Taylor, J.G., & Pearce, A.F. (2001) The seasonal aggregation of whale sharks at Ningaloo Reef, Western Australia: Currents, migrations and the El Nino/Southern Oscillation. SO - Environmental Biology of Fishes. 61(1). May, 2001. 1-11.

Wyatt, A.S.J., Hewitt, C.L., Walker, D.I., & Ward, T.J. (in press) Marine introductions in the Shark Bay World Heritage Property, Western Australia: a preliminary assessment. Diversity and Distributions.

Yap, H.T. (2000) The case for restoration of tropical coastal ecosystems. Ocean & Coastal Management, 43, 841-851.

Zakai, D. & Chadwick-Furman, N.E. (2002) Impacts of intensive recreational diving on reef corals at Eilat, northern Red Sea. Biological Conservation, 105, 179-187.


Appendix A


S1 S2 S3

ANALYST AND DATE: Alex Wyatt, 8/24/2004 Alex Wyatt, 8/24/2004 Alex Wyatt, 8/24/2004

SIEVING ERROR: 0.1% 0.1% 0.1%

SAMPLE TYPE: Unimodal, Very Well Sorted Unimodal, Moderately Well Sorted Unimodal, Moderately Sorted

TEXTURAL GROUP: Sand Sand Sand

SEDIMENT NAME: Very Well Sorted Very Coarse Sand Moderately Well Sorted Coarse Sand Moderately Sorted Coarse Sand

METHOD OF MEAN 34.38 853.6 662.7 MOMENTS SORTING 222.0 359.9 481.2

Arithmetic ( m) SKEWNESS 6.375 0.588 0.334

KURTOSIS 41.89 3.284 2.373 METHOD OF MEAN 1.188 636.2 180.6 MOMENTS SORTING 3.004 3.296 14.89

Geometric ( m) SKEWNESS 6.240 -4.747 -1.348

KURTOSIS 39.96 26.02 2.949 METHOD OF MEAN -0.010 0.351 0.390 MOMENTS SORTING 0.077 0.508 0.633

Logarithmic ( ) SKEWNESS -4.904 -0.089 0.619

KURTOSIS 43.45 3.723 3.267 FOLK AND MEAN 1426.3 813.9 893.6

WARD METHOD

SORTING 0.804 1.551 1.669

( m) SKEWNESS 0.000 0.199 -0.168

KURTOSIS 0.738 1.240 0.515 FOLK AND MEAN -0.512 0.297 0.162

WARD METHOD

SORTING -0.314 0.633 0.739

( ) SKEWNESS 0.000 -0.199 0.168

KURTOSIS 0.738 1.240 0.515 FOLK AND MEAN: Very Coarse Sand Coarse Sand Coarse Sand

WARD METHOD

SORTING: Very Well Sorted Moderately Well Sorted Moderately Sorted

(Description) SKEWNESS: Symmetrical Coarse Skewed Fine Skewed

KURTOSIS: Platykurtic Leptokurtic Very Platykurtic


S4 S5 S6



SAMPLE TYPE: Unimodal, Moderately Well Sorted Unimodal, Well Sorted Unimodal, Moderately Well Sorted


SEDIMENT NAME:

Moderately Well Sorted Very Coarse Sand Well Sorted Very Coarse Sand Moderately Well Sorted Very Coarse Sand


Arithmetic ( m) SKEWNESS -0.412 0.335 0.440


Geometric ( m) SKEWNESS -3.362 -0.551 -0.371


Logarithmic ( ) SKEWNESS 0.016 0.807 1.074


WARD METHOD

SORTING 1.541 1.411 1.440 ( m) SKEWNESS -0.026 -1.130 -1.458

KURTOSIS 0.649 0.477 0.637 FOLK AND MEAN -0.042 -0.036 -0.084

WARD METHOD

SORTING 0.624 0.497 0.527 ( ) SKEWNESS 0.026 1.130 1.458

KURTOSIS 0.649 0.477 0.637 FOLK AND MEAN: Very Coarse Sand Very Coarse Sand Very Coarse Sand

WARD METHOD

SORTING: Moderately Well Sorted Well Sorted Moderately Well Sorted (Description) SKEWNESS: Symmetrical Very Fine Skewed Very Fine Skewed

KURTOSIS: Very Platykurtic Very Platykurtic Very Platykurtic


S7 S8 S9



SAMPLE TYPE: Unimodal, Very Well Sorted Unimodal, Moderately Sorted Bimodal, Poorly Sorted


SEDIMENT NAME: Very Well Sorted Very Coarse Sand Moderately Sorted Fine Sand Poorly Sorted Very Coarse Sand


Arithmetic ( m) SKEWNESS -0.930 3.124 0.539



KURTOSIS 2.820 24.10 1.775 METHOD OF MEAN -0.252 2.053 0.556 MOMENTS SORTING 0.388 0.837 1.140

Logarithmic ( ) SKEWNESS 1.634 -1.461 0.862


WARD METHOD

SORTING 1.236 1.797 2.184

( m) SKEWNESS -1.143 0.433 -0.954

KURTOSIS 0.475 1.233 0.518 FOLK AND MEAN -0.449 2.104 0.434

WARD METHOD

SORTING 0.306 0.845 1.127

( ) SKEWNESS 1.143 -0.433 0.954

KURTOSIS 0.475 1.233 0.518 FOLK AND MEAN: Very Coarse Sand Fine Sand Coarse Sand

WARD METHOD

SORTING: Very Well Sorted Moderately Sorted Poorly Sorted

(Description) SKEWNESS: Very Fine Skewed Very Coarse Skewed Very Fine Skewed

KURTOSIS: Very Platykurtic Leptokurtic Very Platykurtic


S10 T1-0 T1-20



SAMPLE TYPE: Unimodal, Moderately Sorted Unimodal, Well Sorted Unimodal, Moderately Well Sorted


SEDIMENT NAME: Moderately Sorted Very Coarse Sand Well Sorted Very Coarse Sand Moderately Well Sorted Very Coarse Sand


Arithmetic ( m) SKEWNESS 1.053 -2.021 0.410



KURTOSIS 1.111 13.26 1.156 METHOD OF MEAN 0.419 -0.328 0.140 MOMENTS SORTING 0.893 0.356 0.689



WARD METHOD

SORTING 1.807 1.347 1.475

( m) SKEWNESS -1.476 -0.267 -1.584

KURTOSIS 0.760 0.932 0.919 FOLK AND MEAN 0.131 -0.452 -0.128

WARD METHOD

SORTING 0.854 0.430 0.560

( ) SKEWNESS 1.476 0.267 1.584

KURTOSIS 0.760 0.932 0.919 FOLK AND MEAN: Coarse Sand Very Coarse Sand Very Coarse Sand

WARD METHOD

SORTING: Moderately Sorted Well Sorted Moderately Well Sorted

(Description) SKEWNESS: Very Fine Skewed Fine Skewed Very Fine Skewed

KURTOSIS: Platykurtic Mesokurtic Mesokurtic


T1-40 T4-0 T4-20


SIEVING ERROR: 0.1% 0.2% -0.2%

SAMPLE TYPE: Unimodal, Moderately Well Sorted Unimodal, Moderately Well Sorted Unimodal, Moderately Sorted


SEDIMENT NAME: Moderately Well Sorted Very Coarse Sand Moderately Well Sorted Very Coarse Sand Moderately Sorted Very Coarse Sand


Arithmetic ( m) SKEWNESS -0.030 -0.830 -0.329



KURTOSIS 2.143 10.84 3.213 METHOD OF MEAN 0.154 -0.096 0.087 MOMENTS SORTING 0.781 0.473 0.775



WARD METHOD

SORTING 1.621 1.501 1.677

( m) SKEWNESS -0.936 -0.287 -0.786

KURTOSIS 0.607 0.628 0.671 FOLK AND MEAN -0.042 -0.174 -0.103

WARD METHOD

SORTING 0.697 0.586 0.746

( ) SKEWNESS 0.936 0.287 0.786

KURTOSIS 0.607 0.628 0.671 FOLK AND MEAN: Very Coarse Sand Very Coarse Sand Very Coarse Sand

WARD METHOD

SORTING: Moderately Well Sorted Moderately Well Sorted Moderately Sorted

(Description) SKEWNESS: Very Fine Skewed Fine Skewed Very Fine Skewed

KURTOSIS: Very Platykurtic Very Platykurtic Platykurtic


T4-40

ANALYST AND DATE: Alex Wyatt, 8/24/2004

SIEVING ERROR: 0.2%

SAMPLE TYPE: Unimodal, Poorly Sorted

TEXTURAL GROUP: Sand

SEDIMENT NAME: Poorly Sorted Very Coarse Sand

METHOD OF MEAN 395.5 MOMENTS SORTING 457.0

Arithmetic ( m) SKEWNESS 1.448

KURTOSIS 4.096 METHOD OF MEAN 68.89 MOMENTS SORTING 16.35

Geometric ( m) SKEWNESS -0.748

KURTOSIS 1.789 METHOD OF MEAN 0.937 MOMENTS SORTING 1.069

Logarithmic ( ) SKEWNESS 0.276

KURTOSIS 1.671 FOLK AND MEAN 558.5

WARD METHOD

SORTING 2.220

( m) SKEWNESS -0.192

KURTOSIS 0.444 FOLK AND MEAN 0.840

WARD METHOD

SORTING 1.150

( ) SKEWNESS 0.192

KURTOSIS 0.444 FOLK AND MEAN: Coarse Sand

WARD METHOD

SORTING: Poorly Sorted

(Description) SKEWNESS: Fine Skewed

KURTOSIS: Very Platykurtic


Appendix B


ID Taxa Species 1 Brown Alga 1 2 Caulerpa 1 3 Pink Foram Baculogypsina sphaerulata 4 Codium 5 Green Encrusting 6 Red Encrsuting 7 Caulerpa 2 8 Filamentous Brown 9 Brown Alga 2

10 Brown Alga 3 11 Sponge 1 12 Padina 13 Filamentous Green 1 14 Coral 1 15 Sponge 2 16 Coral 2 17 Halimeda 18 Filamentous Green 2 19 Ascidian 1 20 Sponge 3 21 Brown Alga 4 22 Ulva 23 Filamentous Red 24 Ascidian 2 25 Anemone 26 Brown 18 27 Brown 19

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Preliminary survey of the nearshore coastal marine ......To everyones hero, Warwick Crowe, whose...

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