Effects of aquaculture on Mediterranean marine ecosystems

83
Effects of aquaculture on Mediterranean marine ecosystems I. Karakassis, D. Angel

description

Effects of aquaculture on Mediterranean marine ecosystems. I. Karakassis , D . Angel. Effects of aquaculture on marine biotic communities. (modified after Milowski 2001). Posidonia protects the seabed from errosion. Posidonia rhizomes. Plagiotropic rhizome. Orthotropic rhizome. - PowerPoint PPT Presentation

Transcript of Effects of aquaculture on Mediterranean marine ecosystems

Page 1: Effects of aquaculture on Mediterranean marine ecosystems

Effects of aquaculture on Mediterranean marine ecosystemsEffects of aquaculture on Mediterranean marine ecosystems

I. Karakassis, D. Angel

Page 2: Effects of aquaculture on Mediterranean marine ecosystems

Source of pressure Potential effect on biota Level scidocument

Communities affected spatialscale

type ofimpact

Estimatedrecovery of thecommunity

physical structure Direct mortality through entanglement poor Vertebrates local neg mediumBehavioral changes in coastal pelagic fish medium Vertebrates (Fish) local unid unidentifiedBehavioral changes in coastal birds andmarine mammals (e.g., avoidance)

poor Vertebrates loc/int neg unidentified

predator controlsystems

Direct mortality poor Vertebrates loc/int neg unidentified

Behavioral changes of wild fauna medium Vertebrates loc/int neg unidentified

fish escapement Disease transmission to other species poor various (probably fish) int/lar neg unidentifiedGenetic interactions with wild fish High Vertebrates (Fish) int/lar neg slowDisplacement of wild fish from naturalhabitat (e.g., through competition,predation)

poor Vertebrates (Fish) int/lar neg unidentified

release of uneaten foodand feces

Suffocation and displacement of benthicorganisms

High Macrofauna local neg slow

Loss of foraging, spawning and/or nurseryhabitat for wild species

High various local neg slow

Loss of biodiversity High Macrofauna local neg slowFragmentation of benthic habitat poor various loc/int neg slow

release of nutrients Change in water quality poor various loc/int nrg/pos rapidMortality of plankton (including fish andinvertebrate egg and larvae)

poor various local neg rapid

Increased primary productivity poor various loc/int nrg/pos rapidShift in plankton community composition poor Phytoplankton loc/int unid rapidIncrease in harmful algal blooms poor various loc/int neg rapidDecline of seagrass meadows poor-

mediummarine plants & variousindirectly

loc/int neg slow

antibiotics Tainting of wild species poor various local neg rapidChanges in benthic bacterial community poor microbes local neg unidentifiedResistant microbial strains poor various indirectly unkno

wnneg unidentified

pesticides Direct mortality and sublethal effects poor invertebrates local neg unidentifiedTainting of wild species poor various local neg unidentified

disinfectants andantifoulants

Direct mortality and sublethal effects poor invertebrates local neg unidentified

Tainting of wild species poor invertebrates loc/int neg unidentifiedChanges in physiology poor invertebrates loc/int neg unidentified

Effects of aquaculture on marine biotic communities

(modified after Milowski 2001)

Page 3: Effects of aquaculture on Mediterranean marine ecosystems

Posidonia protects the seabed from errosionPosidonia protects the seabed from errosion

Page 4: Effects of aquaculture on Mediterranean marine ecosystems

Posidonia rhizomesPosidonia rhizomes

Plagiotropic rhizome

Orthotropic rhizome

Page 5: Effects of aquaculture on Mediterranean marine ecosystems

Posidonia: provides shelter to juvenile fish and many manire invertebrates

Posidonia: provides shelter to juvenile fish and many manire invertebrates

Spp reproducing in P. oceanica meadows

Lithignathus mormyrusSparus auratus

Oblada melanuraSapra sapra

Paracentrotus lividusSymphodus roissali

Antedon mediterraneusMurena helenaConger conger

Lichia amiaSeriola dumerili

Mullus surmuletus

Page 6: Effects of aquaculture on Mediterranean marine ecosystems

Under anthropogenic pressure Posidonia meadows easily become degraded

Under anthropogenic pressure Posidonia meadows easily become degraded

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… so that its past presence can only be detected by rhizomes left on the seabed

… so that its past presence can only be detected by rhizomes left on the seabed

Page 8: Effects of aquaculture on Mediterranean marine ecosystems

High turbidity in the water column is known to adversely affect Posidonia

High turbidity in the water column is known to adversely affect Posidonia

The reduced availability of light reduces the potential space for colonization by Posidonia to a more and more narrow coastal zone

The reduced availability of light reduces the potential space for colonization by Posidonia to a more and more narrow coastal zone

Page 9: Effects of aquaculture on Mediterranean marine ecosystems

During recent years it has been reported that Posidonia oceanica faces strong copetition by Caulepa taxifolia

During recent years it has been reported that Posidonia oceanica faces strong copetition by Caulepa taxifolia

C. taxifolia is an alien species that recently invaded W. Mediterranean. It has no local grazers or other means to control its population and it excludes P. oceanica from coastal waters when established there

C. taxifolia is an alien species that recently invaded W. Mediterranean. It has no local grazers or other means to control its population and it excludes P. oceanica from coastal waters when established there

Page 10: Effects of aquaculture on Mediterranean marine ecosystems

Why Posidonia is of vital importance

Mediterranean endemic (in need of protection under the Habitat Directive)

a nursery ground for several species provides important services for coastal marine ecosystems

(3D habitat for several invertebrate species) it stabilises the sandy beaches in the littoral zone under increasing pressure due to anthropogenic effects

(pollution, trawling, harbour constructions etc) under increasing pressure due to nutrient enrichment of the

coastal zones and flourish of fast growing macroalgae, e.g. Cladophora spp., Caulerpa sp.

Mediterranean endemic (in need of protection under the Habitat Directive)

a nursery ground for several species provides important services for coastal marine ecosystems

(3D habitat for several invertebrate species) it stabilises the sandy beaches in the littoral zone under increasing pressure due to anthropogenic effects

(pollution, trawling, harbour constructions etc) under increasing pressure due to nutrient enrichment of the

coastal zones and flourish of fast growing macroalgae, e.g. Cladophora spp., Caulerpa sp.

Page 11: Effects of aquaculture on Mediterranean marine ecosystems

Posidonia meadows as fish farming sites

The habitat of The habitat of P. oceanicaP. oceanica (coarse sediment (coarse sediment and strong currents) is “ideal” for fish farming and strong currents) is “ideal” for fish farming since:since:

it allows rapid dispersion of solute wastesit allows rapid dispersion of solute wastes minimal accumulation of particulates and minimal accumulation of particulates and excellent oxygenation of the waterexcellent oxygenation of the water

Page 12: Effects of aquaculture on Mediterranean marine ecosystems

Posidonia is stressed at farming sites

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However f/f causes adverse effects on Posidonia by:

reducing penetration or availability of light reducing penetration or availability of light • immediately under the cages (shadow effect)immediately under the cages (shadow effect)• due to increased phytoplankton biomassdue to increased phytoplankton biomass• due to increased suspended particulatesdue to increased suspended particulates• by favouring the growth of epiphytes on by favouring the growth of epiphytes on PosidoniaPosidonia

leavesleaves competition with fast growing macroalgae competition with fast growing macroalgae accumulation of OM in the sedimentsaccumulation of OM in the sediments increasing NHincreasing NH44 and H and H22S in the sedimentsS in the sediments

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Posidonia: primary production near and far from fish farmsPosidonia: primary production near and far from fish farms

Cancemi et al. (2003) Estuar coastal shelf Sci vol56

Reference station

Farm sites

Changes in pp by an order of magnitude

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MedVeg sampling sites

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MedVeg: sampling design MedVeg: sampling design

MedVeg Report 2005, unpublished data

Page 17: Effects of aquaculture on Mediterranean marine ecosystems

MedVeg fluxes measured with sediment traps

SounionFlux P=0.10*x-0.59

AlicanteFlux P=0.26*x-0.41

MedVeg Report 2005, unpublished data

Page 18: Effects of aquaculture on Mediterranean marine ecosystems

MedVeg BioassaysMedVeg Bioassays

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MedVeg BioassaysMedVeg Bioassays

MedVeg Report 2005, unpublished data

* * * * * * ** * ** * * *

Control siteControl site

* signif different from control site

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MedVeg Bioassays - UlvaMedVeg Bioassays - Ulva

Control siteControl site

* signif different from control site

MedVeg Report 2005, unpublished data

* * * * * * * * * *

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MedVeg: Posidonia mortalities with distance MedVeg: Posidonia mortalities with distance

MedVeg Report 2005, unpublished data

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MedVeg: Posidonia mortalities with sedimentation rate MedVeg: Posidonia mortalities with sedimentation rate

MedVeg Report 2005, unpublished data

Mortality increases rapidly beyond the sedimentation rate of 6g m-2 d-1

Mortality increases rapidly beyond the sedimentation rate of 6g m-2 d-1

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MedVeg: Posidonia density & cover MedVeg: Posidonia density & cover

MedVeg Report 2005, unpublished data

Decrease close to the farms

Decrease close to the farms

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MedVeg: Posidonia biomassMedVeg: Posidonia biomass

MedVeg Report 2005, unpublished data

Decrease close to the farms

Decrease close to the farms

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MedVeg recomendations-2

If monitoring studies indicate a decrease in seagrass meadow extension or shoot density, the amount of waste material (as C, N and P loads) must decrease for a equivalent percentage until recovery of the previous conditions. Alternatively, cages should be moved to other sites, according to guidelines reported above.

Concessionaires must present a plan for the monitoring of possible pressures and damages to seagrass beds and include this in the Environmental Agenda for certification ISO14000 and EMAS (Eco-Management and Audit Scheme).

A suitable monitoring program must use reliable techniques and include quality control procedures, and should be based on the rapid assessment techniques as described below

Page 26: Effects of aquaculture on Mediterranean marine ecosystems

MedVeg descriptors/indicators:at individual plant level

Morphometric descriptors shoot biomass, expressed as the average dry weight

of at least ten replicates shoots Physiological descriptors

total phosphorus content in different tissues, specifically young leaves and rhizomes, expressed as % of dry weight.

total non-structural carbohydrates reserves in rhizomes, expressed as % of dry weight

elemental sulphur content (as μmol per g dry weight) in roots.

Page 27: Effects of aquaculture on Mediterranean marine ecosystems

MedVeg descriptors/indicators:

At population level shoot density, based in counting the number of

shoots inside patches of Posidonia oceanica and expressed as the number of shoots per square meter .

At community level epiphyte biomass, expressed as the dry weigh of

epiphytes in relation of the size of the shoots. sea-urchin density, based on counting the number of

individuals inside patches of Posidonia oceanica and expressed as the number of individuals m-2

Page 28: Effects of aquaculture on Mediterranean marine ecosystems

However... Our results do not mean that any fish farming activity should be banned

at distance less than 800m from any Posidonia oceanica plant in the Mediterranean.

However, adopting this distance could be an appropriate precautionary measure in the vicinity of important and well-developed Posidonia meadows that environmental authorities have set as priority areas for conservation.

Whenever a fish farm is located in the vicinity of seagrass meadows, the health of the seagrass meadow should be annually monitored.

Working definitions of the term "Posidonia meadow" should be harmonised among Mediterranean countries and common standards are set regarding priorities for conservation of such meadows.

Otherwise, it is likely that MedVeg recommendations will be enforced differently in different member states and other Mediterranean countries thereby resulting in both inadequate environmental protection and in violating equal terms of competition within aquaculture industry.

Page 29: Effects of aquaculture on Mediterranean marine ecosystems

Mass balance modelsMass balance modelsSource Species Harvested

(%)Tot wasted

(%)Dissolved

(%)N P N P N P

Hall et al., 1992 trout 28 73 50

Holby & Hall, 1991 trout 18 82 34

Gowen & Bradbury, 1987 salmon 25 75 52

Folke & Koutsky, 1989 salmonids 25 23 75 77 62 11

Ballestrazzi et al., 1994 seabass 31-34 17-29

Dosdat et al., 1996 seabass 77 43-47

Krom et al., 1985 seabream 36 29 64 71

Porter et al., 1987 seabream 30 70 60

Krom et al., 1995 seabream 25 75 60

Dosdat et al., 1996 seabream 43-55

Lanari et al., 1999 seabass 18-21 25-41 79-82 59-75

Kaushik, 1998 seabass 45-55 45-55

Kaushik, 1998 seabream 51-63 38-49

Lupatsch & Kissil, 1998 seabream 22 29 78 71 61 19

Lemarié et al., 1998 seabass 12-17 14-42 93-98 58-86 61-80 24-42

Wallin & Haakanson, 1991 various spp 21-30 15-30 70-79 70-85 49-60 16-26

Working figures max 77 82

min 49 15Karakassis et al. (2005) Sci Mar vol 69

Page 30: Effects of aquaculture on Mediterranean marine ecosystems

Land-based tanksLand-based tanks

input output

Diel high frequency sampling experiments on fluxes of

Nutrients

POC

PON

Bacteria

tanks containing different fish sizes (1, 31 & 53gr)

Diel high frequency sampling experiments on fluxes of

Nutrients

POC

PON

Bacteria

tanks containing different fish sizes (1, 31 & 53gr)

Tsapakis, Pitta, Karakassis (2006) Aquat. Liv. Resour vol 19

sea bass

Page 31: Effects of aquaculture on Mediterranean marine ecosystems

NH4

0.02.04.06.08.0

10.0

“M

in

out

NH4

0.02.04.06.08.0

10.0

“M

in

out

0.00.20.40.60.81.01.2

“ķ

PO4

0.00.20.40.60.81.01.2

“ķ

PO4

Nutrient dynamicsNutrient dynamics

Fish size: 1gr

Significant difference and Diel pattern in dischargeSignificant difference and Diel pattern in discharge

Tsapakis, Pitta, Karakassis (2006) Aquat. Liv. Resour vol 19

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POC

0

100

200

300

400

11:3

014

:30

17:3

020

:30

23:3

02:

305:

308:

30

“g lt

-1

in

out

POC

0

100

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400

11:3

014

:30

17:3

020

:30

23:3

02:

305:

308:

30

“g lt

-1

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out

PON

0

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014

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:30

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“g lt

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out

POC and PON dynamicsPOC and PON dynamics

Significant difference and Diel pattern in dischargeSignificant difference and Diel pattern in discharge

Tsapakis, Pitta, Karakassis (2006) Aquat. Liv. Resour vol 19

Page 33: Effects of aquaculture on Mediterranean marine ecosystems

N & P mass balance: % losses over feed

input

N & P mass balance: % losses over feed

input

14141414

13131313

16161616

13131313

POPO4 4

(%)(%)

POPO4 4

(%)(%)

262626266666AverageAverageAverageAverage

27272727777753535353

29292929555531313131

2121212177771111

NHNH4 4

(%)(%)

NHNH4 4

(%)(%)PON PON (%)(%)

PON PON (%)(%)

Fish Size Fish Size (gr)(gr)

Fish Size Fish Size (gr)(gr)

Fine particulate material settling at very slow rates and over larger distance from the discharge points

Fine particulate material settling at very slow rates and over larger distance from the discharge pointsTsapakis, Pitta, Karakassis (2006)

Aquat. Liv. Resour vol 19

Page 34: Effects of aquaculture on Mediterranean marine ecosystems

Several studies have failed to detect significant changes in dissolved nutrients, Chl-a and POC concentrations even at fairly short distance from the cages (Pitta et al 1998, La Rosa et al., 2002, MEDVEG unpublished data, Soto & Norambuena 2004)

This paradox might be due to: The dispersive nature of the sites (nutrients are rapidly

diluted) Inefficient sampling (concentrations vs fluxes) Intensive grazing and transfer to higher trophic levels Combination of the above

However However

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Grazing experiment in Creteusing dialysis chambers

00 3030 8080 200200 >500>500

Distance (m)Distance (m)

00

22

44

66

88 filteredfiltered

ChlorellaChlorella

unfilteredunfiltered

Ch

l a (g

l-1)

Ch

l a (g

l-1)

Karakassis et al. (submitted)

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Analyses

Local Fisheries landings :time series analysis

Environmental: OC, Chla, Nutrients Fish: Species, Abundance + Biomass per

species, diversity, biodiversity, LF, age, condition factor, fecundity, G Index, stomachs, lipids, proteins

Mega: S, A + B per species, diversity, biodiversity

Macro: S, A, B total, diversity Bacteria: Counts Micro zoo + Phytoplankton: S, A, B (total),

diversity Fish spatial structure: geostatistics

Page 37: Effects of aquaculture on Mediterranean marine ecosystems

Fish communities

Abudance

Far

Near

Stress: 0.16

Biomass

Far

Near

Stress: 0.16

Near

Far

May MayMay SeptemberSeptember

Mud

Mud

Mud

Mud

Mud

Mud

Mud

Mud

Mud

Mud

Mud

Mud

Mud

Mud

Mud

Mud

Mud

Mud

Maerl

Maerl

Maerl

Maerl

Maerl

Maerl

Maerl

Maerl

Maerl

Maerl

Maerl

Maerl

Maerl

Maerl

Maerl

Maerl

Maerl

Maerl

100

80

60

40

Sim

ilarity

Fish Abudance

L L L E E E E E E L L L C C C C C C E E E C C C L L L L L L C C C E E E

Sim

ilari

ty

Far Far FarNear Near

Fine Coarse

May MayMay SeptemberSeptemberMay MayMay SeptemberSeptemberMay MayMay SeptemberSeptemberMay MayMay SeptemberSeptember

Mud

Mud

Mud

Mud

Mud

Mud

Mud

Mud

Mud

Mud

Mud

Mud

Mud

Mud

Mud

Mud

Mud

Mud

Maerl

Maerl

Maerl

Maerl

Maerl

Maerl

Maerl

Maerl

Maerl

Maerl

Maerl

Maerl

Maerl

Maerl

Maerl

Maerl

Maerl

Maerl

100

80

60

40

Sim

ilarity

Fish Abudance

L L L E E E E E E L L L C C C C C C E E E C C C L L L L L L C C C E E E

Sim

ilari

ty

Far Far FarNear Near

Fine CoarseFine Coarse

Fish Abundance

The communities differed firstly according the substrate and secondly according to fish-farms presence.

The effect of fish-farm presence was mainly quantitative

No significant differences in diversity or biodiversity indices (taxon. distinctness etc)

Page 38: Effects of aquaculture on Mediterranean marine ecosystems

Fish communities

Fish Abundance

1,9

2,1

2,3

2,52,7

2,9

3,1

3,3

3,5

EN EF LN LF CN CF

May September

Means and 95.0 Percent LSD Intervals

AreaE1L2X3

log(

XW

)

1 2 38

8.3

8.6

8.9

9.2

9.5

9.8

Means and 95.0 Percent LSD Intervals

AreaE1L2X3

log(

XW

)

1 2 37.6

8

8.4

8.8

9.2

9.6

10

Fine

Coarse

May

The total abundance and biomass was higher near to fish farms in May – and fairly similar in the recruitment period in September. It seems that during the recruitment period all sites (Near and Far) are stocked with fish close to the carrying capacity

Page 39: Effects of aquaculture on Mediterranean marine ecosystems

Effects on LandingsChios

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rms

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Chalkis

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)

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)

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)

Chios

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Lan

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gs

(Kg

)

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Fa

rms

Pro

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cti

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Landings

Farm Production

Patra

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3200000

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19

84

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20

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La

nd

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s (

mT

)

Chalkis

0

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1984

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)

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s (

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) Total LandingsTotal Landings

s Farm Productions Farm Production

Page 40: Effects of aquaculture on Mediterranean marine ecosystems

Effects on Landings: MAFA analysisP

atra

Kav

ala

Ale

xand

roup

olis

Chi

osC

halk

is

1

2

Time

5 10 15

Score

s

0

0.5

A B

+(0)(0)-Chal

+(0)+-Chios

(0)(0)(0)+Alex

(0)(0)(0)+Kav

(0)(0)(0)+Patra

Fish

culture

Temp.RainFishingFleet

Landings

Explanatory VariablesResponse

The correlation between the size of the fishing fleet & the landings trend could be coincidental: due to a clear declining trend because of a vessel withdrawal policy Rainfall & Temperature did not show any correlation with the common trend (except Chios)fish-farming production related to an increase of local fisheries landings

Page 41: Effects of aquaculture on Mediterranean marine ecosystems

AQCESS conclusions

No change in macrofauna Small changes in megafaunal biomass Big change in fish abundance and biomass

documented through: Before-after study: Machias et al 2004, ECSS, v. 60 Near-far study: Machias et al 2005, MEPS, v. 288 Landings: Machias et al. (2006) Aquaculture v. 261 Hydroacoustics: Giannoulaki et al. 2005, JMBA UK v. 85

FAD effect? No, the list of species (<30 spp) aggregating near the cages are known (Dempster et al 2002 MEPS for W. Med, Smith et al submitted from the E. Med). Not the ones increasing in the above studies

No change in macrofauna Small changes in megafaunal biomass Big change in fish abundance and biomass

documented through: Before-after study: Machias et al 2004, ECSS, v. 60 Near-far study: Machias et al 2005, MEPS, v. 288 Landings: Machias et al. (2006) Aquaculture v. 261 Hydroacoustics: Giannoulaki et al. 2005, JMBA UK v. 85

FAD effect? No, the list of species (<30 spp) aggregating near the cages are known (Dempster et al 2002 MEPS for W. Med, Smith et al submitted from the E. Med). Not the ones increasing in the above studies

Page 42: Effects of aquaculture on Mediterranean marine ecosystems

AQCESS conclusions

Not all benthic communities respond in the same way to disturbance

Large long living animals could be more efficient means for monitoring subtle changes

The most possible explanation is the rapid transfer of nutrients up the food web in a nutrient-starving environment

Page 43: Effects of aquaculture on Mediterranean marine ecosystems

sediment: horizontal changessediment: horizontal changes

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600

contr -100 -50 -25 0 5 10 25 50 100

TOC (%)TOC (%) TON (%)TON (%) Eh (mV)Eh (mV)current

current

Cephalonia

Karakassis et al. (2000) ICES J mar sci 57Karakassis et al. (2000) ICES J mar sci 57

Page 44: Effects of aquaculture on Mediterranean marine ecosystems

Meta-analysis of benthic effectsMeta-analysis of benthic effectsauthors year region # ff farmed

organismdepth(m) Sediment type

Angel et al. 1995Red Sea, J ordan 1 bream-bass 15-35 fine sandKarakassis et al. 1999Mediterranean, Greece 3 bream-bass 20-40 mud, coarse sandKatavic and Antolic 1999Mediterranean, Croatia 1 bream-bass 23 sandKarakassis et al. 2000Mediterranean, Greece 3 bream-bass 20-40 mud, coarse sandMirto et al. 2000Mediterranean, Italy 1 bream-bass 10 silty sandMolina-Dominguez et al. 2001Atlantic, Spain 1 bream-bass 20 sandLa Rosa et al. 2001Mediterranean, Italy 1 bream-bass 10 silty sandYokoyama 2002Pacific, J apan 2 bream-bass 14-23 silty sandAngel and Spanier 2002Red Sea, Israel 1 bream-bass 20Belias et al. 2003Mediterranean, Greece 3 bream-bass 9-42 rocky, mudGowen et al. 1988Atlantic, Scotland 2 Salmonidae 20-25 mud, coarse (gravel)Rosenthal and Rangeley 1989Atlantic, Canada 1 Salmonidae 9 mudRitz et al. 1989Pacific, Australia 1 SalmonidaeHall et al. 1990Baltic, Sweden 1 Salmonidae 20 mudWeston 1990Pacific, USA 1 Salmonidae 16 sandKupka-Hansen et al. 1991Atlantic, Norway 1 Salmonidae 7-20 sandLauren-Maatta et al. 1991Baltic, Finland 4 Salmonidae 7-20Uotila 1991Baltic, Finland 1 Salmonidae 8Holby and Hall 1991Baltic, Sweden 1 Salmonidae 20 mudYe et al. 1991Pacific, Australia 1 Salmonidae 12 fine sandHolmer and Kristensen 1992Atlantic, Dermark 1 Salmonidae 5Hall et al. 1992Baltic, Sweden 1 Salmonidae 20 mudHargrave et al. 1993Atlantic, Canada 1 Salmonidae 13 mudHolby and Hall 1993Baltic, Sweden 1 Salmonidae 20 mudJohnsen et al. 1993Atlantic, Norway 1 Salmonidae 13-18 fine sandFindlay et al. 1995Atlantic, USA 1 Salmonidae 16 silty sandBlack et al. 1996Atlantic, Scotland 2 Salmonidae 16-33 mud, sandFindlay and Watling 1997Atlantic, USA 3 Salmonidae 11-15 silty sand, coarseHargrave et al. 1997Atlantic, Canada 1 Salmonidae 14 mudMorrisey et al. 2000Pacific, New Zealand 1 Salmonidae 26 silty sandKraufvelin et al. 2001Baltic, France 2 Salmonidae 5-25Pohle et al. 2001Atlantic, USA 3 Salmonidae 13 mudHeilskov and Holmer 2001Atlantic, Dermark 1 Salmonidae 5 mudWildish et al. 2001Atlantic, Canada 1 Salmonidae mudCromey et al. 2002Atlantic, Scotland 2 SalmonidaeKempf et al. 2002Atlantic, France 1 Salmonidae 20 silty sandWildish et al. 2003Pacific, Australia 2 Salmonidae mudNickell et al. 2003Atlantic, Scotland 1 Salmonidae 15-22 mudBrooks et al. 2003Pacific, Canada 2 Salmonidae sandPocklington et al. 1994Atlantic, Canada 4 Salmonidae mudCheshirel et al. 1996Pacific, Australia 1 Tuna

Kalantzi & Karakassis (2006) Mar. Pollut. Bull vol 52

Page 45: Effects of aquaculture on Mediterranean marine ecosystems

Meta-analysis of benthic effectsMeta-analysis of benthic effectsTable 4. Results of multiple stepwise regression for all data points comprising all sediment types (*p<0,05, ** p<0,01, *** p<0,005)

  Constant LNDIST Depth LatitudeNumber

of %

Variable coefficient p coefficient p coefficient p coefficient p samples variance

TOC -0,086*** -0,006*** 0,00044- 0,003*** 218 36,1LOI -0,023- -0,014*** 0,004*** 109 43,5TON -0,017*** -0,001*** 0,00015*** 0,00043*** 172 25,8EH2,4CM 118,100- 24,226*** 3,876* -3,816* 161 22,5O2BENT -30,674- -15,749*** 3,295- 79 9,5DOBOT -18,506* 0,439*** 0,475* 0,238*** 50 26,2SHANNON 3,314*** 0,233*** 0,076*** -0,068*** 161 68,6EVENNESS 15,171*** -0,163*** -0,216*** 109 26NUMSP 75,602*** 0,950*** -1,339*** 180 51,2LNABUND 13,078*** -0,067*** -0,074*** 214 6,4LNBIOM 4,412*** 0,175*** -0,060***    123 20

Kalantzi & Karakassis (2006) Mar. Pollut. Bull vol. 52

Page 46: Effects of aquaculture on Mediterranean marine ecosystems

Meta-analysis of benthic effectsMeta-analysis of benthic effectsTable 4. Results of multiple stepwise regression per sediment type (* p<0.05, ** p<0.01, *** p<0.005)

Constant LNDIST Depth Latitude Number of %variable Coeff. t p Coeff p Coeff p Coeff p samples variance

Muddysediment

TOC 0.050** -0.006*** -0.001- 0,001*** 90 27.6TON 0.010*** -0.00022*** -0.0004* 42 55.1SHANNON -0.021- 0.314*** 0,088*** 65 77.9NUMSP 20.054*** 5.514*** 22 37.2LOGABU 11.200*** -0,119- 22 12.1LOGBIOM 3.172- 0.185- -0.149** 0.078* 20 65.8

Sandysediment

TOC -0.125*** -0.004* 0.010*** 84 58.7TON 0.032*** -0.001*** 0.002*** -0.001*** 81 58.8SHANNON 4.464*** 0.386*** -0.078*** 67 49.1NUMSP 205.105*** 6.314** -11.222*** 28 54.6LOGABU 2.604- 0.287*** 0.131*** 77 21.5LOGBIOM -3.311* 0.763*** -0.287*** 0.221*** 41 67.3

Coarsesediment

TOC -0.055*** -0.002*** 0.002*** 63 78.9TON -0.042*** -0.00019*** 0.0004* 0.001*** 55 44.2SHANNON 86.015** 0.391*** -2.186* 24 46NUMSP 52.135*** 4.922- 24 10.4LOGABU -33.543- -0.501*** 0.055- 1.110- 24 71.4LOGBIOM -42.622* -0.463*** 0.041- 1.205* 24 73.6

Page 47: Effects of aquaculture on Mediterranean marine ecosystems

Sediment profiling imagery (SPI): an «inverted periscope»

mirrorglass

camera

Page 48: Effects of aquaculture on Mediterranean marine ecosystems

SPI images beneath fish farmsSPI images beneath fish farms

BgBgCH4 or HCH4 or H22SS

UFUF

FSFS

FSFS

BLTBLTBLTBLT

BTBT

Source: Karakassis, Tsapakis, Smith, Rumohr. (2002) Mar Ecol Prog Ser, 227Source: Karakassis, Tsapakis, Smith, Rumohr. (2002) Mar Ecol Prog Ser, 227

Page 49: Effects of aquaculture on Mediterranean marine ecosystems

Multivariate analysis of SPI data

SourceSource: Karakassis, Tsapakis, Smith, Rumohr. (2002) : Karakassis, Tsapakis, Smith, Rumohr. (2002) Mar Ecol Prog SerMar Ecol Prog Ser 227 227

February JulyOctober

Euclidean distance

Oct Feb July Oct Feb July

Fauna October 1

Fauna February 0.903 1

Fauna July 0.794 0.770 1SPI October -0.927 -0.782 -0.794 1

SPI February -0.939 -0.927 -0.685 0.818 1SPI July -0.442 -0.527 -0.794 0.358 0.467 1

Comparisons Comparisons between between multivariate multivariate patternspatterns

faunafauna SPISPI

Page 50: Effects of aquaculture on Mediterranean marine ecosystems

0.00

0.25

0.50

0.75

1.00

Species Genus Family Order Class Phylum

taxonomic resolution

Corers >1mmvanVeen >1mm

Corers combinedvanVeen combined

All correlation coefficient values were significant (p<0.001)

Minimizing monitoring requirements

Lampadariou, Karakassis, Pearson (2005) Mar. Pollut Bull vol 50

Page 51: Effects of aquaculture on Mediterranean marine ecosystems

Modelling spatial patterns of settling

particles

DEPOMOD -> MERAMOD

Modelling spatial patterns of settling

particles

DEPOMOD -> MERAMODA tool for prediction of benthic degradationHigh correlation between predicted and observed sedimentationHigh correlation between predicted sedimentation and macrofaunal diversity

A tool for prediction of benthic degradationHigh correlation between predicted and observed sedimentationHigh correlation between predicted sedimentation and macrofaunal diversity

Cromey et al. in preparation

Page 52: Effects of aquaculture on Mediterranean marine ecosystems

Sedimentation by fish farmsSedimentation by fish farms

* for trout cage farming in Swedenby Holby & Hall (1991) and by Hall et al. (1992) MEPS

* for trout cage farming in Swedenby Holby & Hall (1991) and by Hall et al. (1992) MEPS

Fish food 94-97 %

Loss of fish 1 - 4 %

Sedimentation

External food

Solute release

25-30 %

Sediment accumulation 47-54 %

benthic flux 2-4 %

50-57 %

P Juveniles 3-6 %

Harvest 17-19 %

Fish food 93-95 %

Loss of fish 2-5 %

Sedimentation

External food

Solute release 48 %

Sediment accumulation 12-20 %

benthic flux 1-3 %

23 %

N Juveniles 5-7 %

Harvest 27-28 %

Page 53: Effects of aquaculture on Mediterranean marine ecosystems

effects on benthoseffects on benthos

AbundanceBiomassDiversity

Distance (temporal or spatial) from pollution source

Ecotone

transitory zone

opportunistic species peak

Azoic

zon

e

aerobic sediment

Grossly polluted

Polluted Transitory Normal

anaerobic sediment

Pearson & Rosenberg (1978)Pearson & Rosenberg (1978)

Page 54: Effects of aquaculture on Mediterranean marine ecosystems

Hierarchical response to stress

Pearson & Rosenberg (1978)

Physiological reponse of the individual

Replacement by more addapted individuals from a polymorphic stock

Replacement by different species

Replacement by different genus

Replacement by different family

Replacement by different order,class, phylum

time

str

ess

Page 55: Effects of aquaculture on Mediterranean marine ecosystems

Biotic coefficient (BC) - AMBIBiotic coefficient (BC) - AMBI The BC proposed by Borja et al (2000) distributes

species into various groups depending on their ability to tolearate disturbence/pllution• Group I. Sensitive species, present only in complete

absence of pollution• Group II. Indifferent species always present in small

densities without significant fluctuation with time• Group III. Tolerant species. they may be found under

natural conditions but their population growth is stimulated under organic enrichment

• Group IV. Second stage opportunists. Mainly small-size subsurface deposit feeders (e.g. Cirratulidae)

• Group V. First stage opportunists. Deposit feeders thriving in reduced sediments.

Page 56: Effects of aquaculture on Mediterranean marine ecosystems

Biotic coefficient (BC)Biotic coefficient (BC)

The value of BC is then calculated for every sample based on the % of each group on total macrofaunal abundance.

(0xGI)+(1.5xGII)+(3xGIII)+(4.5xGIV)+(6xGV)BC=

100

This index is supported by a software in EXCEL (AMBI) and a data base providing characterization of >3000 benthic species (www.azti.es)

Borja A, Franco J, Perez V (2000) A marine biotic index to establish the ecological quality of soft-bottom benthos within European estuarine and coastal environments. Marine Pollution Bulletin 40:1100–1114.

Muxika I, Borja A, Bonne W (2005) The suitability of the marine biotic index (AMBI) to new impact sources along European coasts. Ecol. Indic, 5:19–31.

Page 57: Effects of aquaculture on Mediterranean marine ecosystems

Limits for BCLimits for BC

Borja et al (2000) Mar Pollut Bull 401100–1114.

classificationIn terms of pollution BC Dominant groupBenthic community health

Non polluted 0.0<BC<0.2 I normalNon polluted 0.2<BC<1.2 poor

Slightly polluted 1.2<BC<3.3 III unbalancedModerately polluted 3.3<BC<4.3 Transitional to polluted

Moderately polluted 4.3<BC<5.0 IV-V pollutedHeavily polluted 5.0<BC<5.5 Transitional to havily polluted

Heavily polluted 5.5<BC<6.0 V Heavily polluted

extremely polluted αζωική αζωική azoic

Page 58: Effects of aquaculture on Mediterranean marine ecosystems

BENTIXBENTIX BENTIX (Benthic index) is a variation of BC proposed by

greek scientists (Simboura &, Zenetos 2002) The difference from BC is that BENTIX recognizes only

3 groups of species and the list of species for which there is some characterization is not available except the first edition in Mediterranean Marine Science.

Because BENTIX is calculated giving high scores to intolerant species low values indicate degradation whereas high values «pristinity»

Simboura N, Zenetos A. (2002) Benthic indicators to use in ecological quality classification of Mediterranean soft bottom marine ecosystems including a new Biotic index. Mediterranean Marine Science 3:77–111.

Page 59: Effects of aquaculture on Mediterranean marine ecosystems

BC and BENTIX

Both methods are based on subjective judjment on the ecological role of benthic species

Their use needs communication with the authors (direct or indirect through their web page) and up to a point confidence in their oppinion.

The role of each species and the assignment of one group is inflexible and is given only once.

There is no agreed procedure for revising the classification of a species in the groups of each index

The thershod values assigned are more or less arbitrary.

Page 60: Effects of aquaculture on Mediterranean marine ecosystems

Benthic quality index (BQI)Benthic quality index (BQI)

BQI (proposed by Rosenberg et al 2004) is somehow different than the previous indices.

Species are not divided into categories but they receive a score depending on their disdtribution in a set of samples

The index is based on the assumption that opportunistic species are primarily found in stations/samples with low diversity whereas the «normal» or sensitive species in stations/samples with increased diversity.

Therefore if the distribution of a species is determined over a series of samples covering a wide range of diversity then the distribution pattern will vary from species to species depending on their sensitivity or tolerance.

Rosenberg R, Blomqvist M, Nilsson HC, Cederwall H, Dimming A (2004) Marine Pollution Bulletin 30 (7), 470 –474

Page 61: Effects of aquaculture on Mediterranean marine ecosystems

Calculation of ES500.05

Calculation of ES500.05

disturbed undisturbeddisturbed undisturbed

The shaded area includes the 5% of the total abundance of the species which is related to low diversity stations

The shaded area includes the 5% of the total abundance of the species which is related to low diversity stations

Rosenberg R, et al. (2004). Rosenberg R, et al. (2004). Mar Pollut. Bull. 30:470 –474Mar Pollut. Bull. 30:470 –474

Page 62: Effects of aquaculture on Mediterranean marine ecosystems

Calculation of ES500.05 for various speciesCalculation of ES500.05 for various species

Low values: tolerant species, High values: sensitive speciesΧαμηλές τιμές: ανθεκτικά είδη, Υψηλές τιμές: ευαίσθητα είδη

Low values: tolerant species, High values: sensitive speciesΧαμηλές τιμές: ανθεκτικά είδη, Υψηλές τιμές: ευαίσθητα είδηRosenberg R, et al. (2004). Mar Pollut. Bull. 30:470 –Rosenberg R, et al. (2004). Mar Pollut. Bull. 30:470 –

474474

Page 63: Effects of aquaculture on Mediterranean marine ecosystems

After calculating ES500.05 for each species, BQI is

calculated for each sample:

BQI= ------ x ES500.05 x 10log(S+1)

Benthic quality index (BQI)Benthic quality index (BQI)

n

Σi=1( ))( AAii

tot Atot A

Page 64: Effects of aquaculture on Mediterranean marine ecosystems

BQI and sediment conditionBQI and sediment condition

Rosenberg R, et al. (2004). Mar Pollut. Bull. 30:470 –Rosenberg R, et al. (2004). Mar Pollut. Bull. 30:470 –474474

SPI imagesSPI images

Condition in relation to Pearson & Rosenberg 1978

Condition in relation to Pearson & Rosenberg 1978

Thresholds and sediment qualityThresholds and sediment quality

Page 65: Effects of aquaculture on Mediterranean marine ecosystems

Hypotheses to test

Do all these indices describe the conditions similarly?

Are they intercorrelated? Do they depend on sieve size? Do they depend on season? Do they assign the same environmental

quality to the samples examined?

Page 66: Effects of aquaculture on Mediterranean marine ecosystems

Sieve size

0

1

2

3

4

5

6

7

8

0

1

2

3

4

5

6

7

0

5

10

15

20

25

30

35

0 10 20 30 40

0

2

4

6

8

60

70

80

90

100

110

D+ (0.5mm)

0

2

4

6

8

10

Values at 0.5 mm

Val

ues

at 1

.0 m

m

Highly correlated y=1.0*x

Good news !

Page 67: Effects of aquaculture on Mediterranean marine ecosystems

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

Shannon BQI Benthix S BC ES10 L+ D+

July-Sept (0.5mm)

July Feb (0.5mm)

season

index

Spe

arm

an r

ank

corr

elat

ion

Highly inter- correlated for most indices Relatively Good news !

Page 68: Effects of aquaculture on Mediterranean marine ecosystems

Do they intercorrelate? Highly inter- correlated (p<0.01) for most indices Relatively Good news ! So we can chose any of them without worrying?

ES10 H' DELTA+ LAMBDA+ AMBI BENTIX BQIES10 1H' 0.970 1DELTA 0.457 0.480 1LAMBDA -0.238 -0.287 -0.616 1AMBI -0.740 -0.764 -0.541 0.344 1BENTIX 0.739 0.735 0.431 ns -0.810 1BQI 0.891 0.918 0.517 -0.296 -0.791 0.807 1

Page 69: Effects of aquaculture on Mediterranean marine ecosystems

How similar they are? Using the correlation matrix we can run an

MDS and obtain similarities among indices

D+

L+

AMBI

BENTIX

H’BQI

Stress:0.01

Page 70: Effects of aquaculture on Mediterranean marine ecosystems

Do they agree in Environmental status?

bad

Well… No In fact they reach a «consensus» in 4% of the samples and

they had 3-4 different «verdicts» in 39% of the samples

0

1

2

3

4

5

0 20 40 60 80 100

sampling station

AMBI

BQI

BENTIX

H'

poor

moderate

good

high

Page 71: Effects of aquaculture on Mediterranean marine ecosystems

Are there consistently easy-to-pass and difficult ones?

Yes BENTIX and H’ tend to show more High and Good quality BQI tends to show (reveal?) more Bad and Poor conditions

0%

25%

50%

75%

100%

1.High 2.Good 3.Moderate 4. Poor 5. Bad

Environmental status

BQI

AMBI

BENTIX

H'

Page 72: Effects of aquaculture on Mediterranean marine ecosystems

furthermore The Pearson & Rosenberg model works well

with silty sediments For coarse sediments it is possible to have a

“healthy picture” despite the fact that environmental degradation may have severely affected other components of the ecosystem.

Page 73: Effects of aquaculture on Mediterranean marine ecosystems

Χαρακτηριστικά των ιχθυοτροφείων στο δείγμα (fish farms characteristics)

0

5

10

15

20

25

30

130 260 300 300 309 366 400 432 443 1094 1150

0

10

20

30

40

50

60

70

80

90depth silt

Βά

θος

(m)

dep

th

% ι

λύος

αργ

ίλου

(%

sil

t-cl

ay)

Παραγωγή (τόνοι/έτος)Production (tn/year)

Page 74: Effects of aquaculture on Mediterranean marine ecosystems

Αριθμός ειδών (species number)

1

10

100

0 200 400 600 800 1000 1200

0m

# sp

ecie

s

Παραγωγή (τόνοι/έτος)Production (tn/year)

25m

1

10

100

1000

0 200 400 600 800 1000 1200

25m

Minimum=5spp

Minimum=32spp

Page 75: Effects of aquaculture on Mediterranean marine ecosystems

Μέσος αριθμός ειδών (average species number)

Ave

rage

# s

pec

ies

Απόσταση Distance

020406080

100120140160

0m 5m 10m 25m 50m control

μέσ

ος α

ριθμ

ός ε

ιδώ

ν

Page 76: Effects of aquaculture on Mediterranean marine ecosystems

Δείκτης Shannon (Shannon index)H

’ (b

its)

Παραγωγή (τόνοι/έτος)Production (tn/year)

01

2345

67

0 200 400 600 800 1000 1200

0m

01234567

0 200 400 600 800 1000 1200

25m

Page 77: Effects of aquaculture on Mediterranean marine ecosystems

Δείκτης Shannon (Shannon index)

H’

(bit

s)

Απόσταση Distance

0

1

2

34

5

6

7

0m 5m 10m 25m 50m control

Page 78: Effects of aquaculture on Mediterranean marine ecosystems

Δείκτης Bentix (BENTIX index)B

enti

x in

dex

Παραγωγή (τόνοι/έτος)Production (tn/year)

0

1

2

3

4

5

6

0 200 400 600 800 1000 1200

0m

0

1

2

3

4

5

6

0 200 400 600 800 1000 1200

25m

Poor-bad

Poor-bad

Page 79: Effects of aquaculture on Mediterranean marine ecosystems

Δείκτης AMBI (AMBI index)A

MB

I in

dex

Παραγωγή (τόνοι/έτος)Production (tn/year)

0

1

2

3

4

5

6

7

0 200 400 600 800 1000 1200

0m

0

1

2

3

4

5

0 200 400 600 800 1000 1200

25m

Poor-bad

Poor-bad

Page 80: Effects of aquaculture on Mediterranean marine ecosystems

Δείκτης AMBI σε όλα τα δείγματα (AMBI index, all samples & stations)

AM

BI

cate

gori

es (

%)

Απόσταση (m) Distance

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

0 5 10 25 50 ctrl

κατη

γορ

ίες

(%)

High

Good

Moderate

Poor

Bad

Page 81: Effects of aquaculture on Mediterranean marine ecosystems

Δείκτης Shannon σε όλα τα δείγματα (H’ index, all samples & stations)

Sh

ann

on c

ateg

orie

s (%

)

Απόσταση (m) Distance

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

0 5 10 25 50 ctrl

κατη

γορ

ίες

(%)

High

Good

Moderate

Poor

Bad

Page 82: Effects of aquaculture on Mediterranean marine ecosystems

Δείκτης BENTIX σε όλα τα δείγματα (BENTIX index, all samples & stations)

BE

NT

IX c

ateg

orie

s (%

)

Απόσταση (m) Distance

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

0 5 10 25 50 ctrl

κατη

γορ

ίες

(%)

High

Good

Moderate

Poor

Bad

Page 83: Effects of aquaculture on Mediterranean marine ecosystems

Thank you