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Seagrass community assessment: two case studies from the

Philippines

Hildie Maria NacordaMarine Science InstituteUniversity of the Philippines

Case 1: North Palawan (NP)? Specific objectives:

? to conduct an extensive baseline assessment of seagrass communities in 8 municipalities of North Palawan;

? to describe seagrass distribution patterns, if any; ? composition, structure, diversity

? to recommend seagrass priority management area(s) in each municipality.

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? Primary use of assessment results: zoning for tourism

? Time, manpower, trade-off? limited field days per municipality (regardless of

coastline length!)? <10 semi-skilled to very skilled personnel per

survey? trade-off: level of detail

Case 1: North Palawan (NP)

Secondary data from NRDB Pro 1.05? Natural Resources Database software ? Palawan Corridor Strategy Development

software developed by Richard Alexander? licensed to Conservation International? powerful Windows-based GIS tool for

developing countries? free for distribution

? outputs: spreadsheets, maps

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119 120

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9.50 N, 118.70 E

10.30 N, 118.80 E

? Puerto Princesa City: survey of status following inventories dated 1987 to 2002

9.50 N, 118.70 E

10.30 N, 118.80 E

April 2005 survey

? 12 legs in 12 days (4/13-24)

? 91 stations, 11 islands? 9 skilled personnel

13 boat trips1 city jeepney1 4-wheel drive

? Kind supportfrom private enterprise

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Field methods

? Access stations (GPS);

? Establish transects’direction (perpendicular); note headings

? Read bottom data at systematic points along the transects;

? Save seagrass edges as coordinates (GPS)

At the end of the day…

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9.50 N, 118.70 E

Puerto Princesa Bay First impressions:

dominant dominant EnhalusEnhalus population population

30-50% seagrass cover, 4-7 species

9.50 N, 118.70 E

Puerto Princesa Bay dominant dominant SargassumSargassum standsstands

relatively exposed shorelinerelatively exposed shoreline4-16% seaweed cover, 4-16 genera

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9.50 N, 118.70 E

Puerto Princesa Bay

hard substratum & seaweedshard substratum & seaweeds

dense mix of 4dense mix of 4--7 seagrass species7 seagrass species

9.50 N, 118.70 E

Puerto Princesa Bay

feeding trail of the dugongfeeding trail of the dugong

grouper culture (BFAR)grouper culture (BFAR)

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9.50 N, 118.70 E

Puerto Princesa Bay

dense mix off the wide mudflatdense mix off the wide mudflat

shallow & narrow but diverse mixshallow & narrow but diverse mix

9.50 N, 118.70 E

Outer Honda Bay - Sextensive, dense & diverse mix extensive, dense & diverse mix of seagrassesof seagrasses

fish juveniles in the most fish juveniles in the most extensive bed (1.5 km!)extensive bed (1.5 km!)

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Honda Bay coast

EnhalusEnhalus on muddy sandon muddy sand

Mangroves that protect the Mangroves that protect the coastlinecoastline

Honda Bay coast

Epiphytes on seagrass leavesEpiphytes on seagrass leaves

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Honda Bay islands

young catfishyoung catfish

less epiphytes on bladesless epiphytes on blades

PundeadoPundeado: dense community: dense community

narrow reef flatnarrow reef flat

Honda Bay islands

cyanide use?? algal growthcyanide use?? algal growth

seasonal desiccationseasonal desiccation

DiademaDiadema aggregationaggregation

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Outer Honda Bay (north)

TurbinariaTurbinaria

beachbeach

dropdrop--offsoffs

bouldersboulders

Outer Honda Bay (north): deep meadow!!

feeding trail of dugongfeeding trail of dugong

H. H. uninervisuninervis & S. & S. isoetifoliumisoetifolium

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10.30 N, 118.80 EUlugan Bay

sparse sparse EnhalusEnhalus

PadinaPadina on rockon rock

dropdrop--offs aheadoffs ahead……

mangroves mangroves

pristine beachespristine beaches

rocky shoresrocky shores

10.30 N, 118.80 ECabayugan-New Panggangan

THREAT?

some some HalophilaHalophila

Red tide slick

pristine beachespristine beaches

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Napsan-Bacongan

Red tide slick

pristine beachespristine beachesrocky shoresrocky shores

bouldersboulders

fish corralfish corral

9.50 N, 118.70 E

10.30 N, 118.80 E

From the first impressions…? the east coast of

Puerto PrincesaCity have:

? well-covered meadows;

? diverse seagrass communities; and

? feeding grounds of the dugong

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Based on analyzed data: distribution maps

9.50 N, 118.70 E

10.30 N, 118.80 E

0

4

8

12

16

20

100 200 300 400 500 1000 1500

bed width, m

N st

atio

ns

? indicative bed widths

Species occurrence? Enhalus acoroides

9.50 N, 118.70 E

10.30 N, 118.80 E

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? Enhalus acoroides? Thalassia hemprichii

Species occurrence

? Enhalus acoroides? Thalassia hemprichii? Cymodocea rotundata

Species occurrence

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? Enhalus acoroides? Thalassia hemprichii? Cymodocea rotundata? Cymodocea serrulata

Species occurrence

? Enhalus acoroides? Thalassia hemprichii? Cymodocea rotundata? Cymodocea serrulata? Syringodium isoetifolium

Species occurrence

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? Enhalus acoroides? Thalassia hemprichii? Cymodocea rotundata? Cymodocea serrulata? Syringodium isoetifolium? Halodule uninervis

Species occurrence

? Enhalus acoroides? Thalassia hemprichii? Cymodocea rotundata? Cymodocea serrulata? Syringodium isoetifolium? Halodule uninervis? Halophila ovalis

Species occurrence

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Species richness

9.50 N, 118.70 E

10.30 N, 118.80 E

0

200

400

1 2 3 4 5 6 7 8

N species

n p

lots

0

2

4

6

8

10

1 2 3 4 5 6 7 8

N species

n st

atio

ns

Seagrass leaf canopy cover on bottom

9.50 N, 118.70 E

10.30 N, 118.80 E

? ?plots????????

0

100

200

300

400

0 10 25 50 75 100

leaf canopy cover, %

N p

lots

0

5

10

15

20

0 10 25 50 75 100

leaf canopy cover, % (pooled)

N s

tatio

ns

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Contribution of seaweeds to bottom cover

9.50 N, 118.70 E

10.30 N, 118.80 E

? very little…

9.50 N, 118.70 E

10.30 N, 118.80 E

Unique feature: dugong feeding trails

? prominent!!

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Criteria of seagrass areas for priority management (core zones)

? Seagrass beds bordering core zone for mangrove and corals

? Seagrass beds with at least 50% cover of macrophytes

? Seagrass beds with sightings of dugong

We propose also:? Seagrass beds composed of at least 4

seagrass species

(http://www.pcsd.ph/resolutions/sep/res94-44.htm)

Proposed seagrass core zones

9.50 N, 118.70 E9.50 N, 118.70 E9.50 N, 118.70 E9.50 N, 118.70 E

? sites with overlap of? good seagrass leaf

canopy cover;? composed of at least 4

seagrass species;? presence of dugong

feeding trails

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And then?

9.50 N, 118.70 E9.50 N, 118.70 E9.50 N, 118.70 E9.50 N, 118.70 E

? refinements of zoning from:? overlay of other

coastal/ marine core zones

? coral reefs

? mangroves

? overlay of uses

? traditional? multiple

Case 2: Bolinao? Specific objectives:

? to ground-truth bottom types of selected coordinates in an analyzed remote sensing image;

? to conduct an extensive and quantitative baseline assessment of seagrass communities;

? to describe seagrass distribution patterns, if any; and

? to recommend pilot sites for the BSDS Project.

UNEP/GEFSouth China Sea Project

Marine Environment andResources Foundation, Inc.

Bolinao SeagrassDemonstration Site

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Image analysis

Figure 1. Bolinao, December 2000 – The LandSat enhanced thematic map used for the analysis of major marine bottom types. (Courtesy of the BAR-AFMA/UPMSI Ocean Color for Sustainable Fisheries Project)

Secondary data

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Image analysis

Figure 2. Bolinao, December 2000 – the distribution of the five major marine bottom types classified from the LandSat enhanced thematic map.

Image analysis

Figure 3. Ground-truthing – The scatter of 200 waypoints on the classified image of Bolinao that were planned for bottom type verifications.

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“Oceans 10”

Sea-truthing: waypoint search

Figure 4. Ground-truthing – A target waypoint would usually be accessed easily by boat, except during low tide. (Photo: G Regino)

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Sea-truthed waypoints

??

SantiagoIsland

BOLINAO

Seaweeds on hard bottoms

(Photos: W Mendoza, H Nacorda)

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Invertebrates on hard bottoms

(Photos: W Mendoza, H Nacorda)

Seagrass-associated seaweeds

(Photos: W Mendoza, H Nacorda)

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Seagrass-associated invertebrates

(Photos: W Mendoza, H Nacorda)

Seagrass habitat uses

(Photos: W Mendoza, H Nacorda, G Regino)

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Urchin encounters16.45 N119.95 E

16.40 N119.85 E

? Tripneustes gratilla? Salmacis sphaerioides? Diadema setosum

Seagrass shoots grazed by T. gratilla

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Dense and less dense seagrass bottoms

Dense and less dense seagrass bottoms16.45 N119.95 E

16.40 N119.85 E

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Lush beds

Sampling seagrasses

bb cc dd

aa

(Photos: H Nacorda)

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Apparent flowers and fruits16.45 N119.95 E

16.40 N119.85 E

Seagrass species richness, N16.45 N119.95 E

16.40 N119.85 E

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5

10

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1 2 3 4 5 6 7

n species

n st

atio

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Seagrass densities16.45 N119.95 E

16.40 N119.85 E

0

5

10

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500 1500 2500 3500 4500 5500

Density classes

n st

atio

ns

Seagrass species diversity, H’16.45 N119.95 E

16.40 N119.85 E

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4

8

12

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0 0.5 1 1.5 2 2.5

species diversity, H

nsta

tions

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Coral

Sand

Seagrass

Mixed

The Bolinao Seagrass ReserveThe Bolinao Seagrass ReserveMunicipal Ordinance 2007-02, 21 March 200760 ha (0.60 km2)- 40 ha, buffer zone-20 ha, core zone

Municipal Ordinance Municipal Ordinance 20072007--02, 02, 21 March 200721 March 200760 ha (0.60 km2)60 ha (0.60 km2)-- 40 ha, buffer zone40 ha, buffer zone--20 ha, core zone20 ha, core zone