Extent of influence of salmon farms on benthic     community and trophic structure                       Myriam Callier   ...
Aquaculture waste into the food web                                               Food      dissolved      Excretion      ...
Objectives• Determine the influence of aquaculture waste  on benthic communities2. Assess the contribution of aquaculture ...
• Influence of aquaculture waste on benthic  communitiesHypotheses:3. Abundance and diversity of benthic macrofauna will v...
Study sitesMulroy Bay, Co. Donegal, Republic of Ireland       Mulroy Bay                        Millstone                 ...
1- MethodologyMillstone farm = M                     T1   200m        T2                          25m                     ...
0m                                  25m                             20                                  200m b            ...
0m                                  25m                             20                                  200m b            ...
1- Community structure                                                                         Maldanidae                 ...
1- Summary Localised organic enrichment due to salmon farming Effects extend < 25 m, perpendicular to current Effects e...
2. Assess the contribution of aquaculture waste   in the benthic organism’s dietStable isotope (SI) increasingly used to d...
3- MethodologyArtificial substrates                                   200 m                                   25 m        ...
2- MethodologySOURCES OF ORGANIC MATTER          CONSUMERS                Salmon                Faeces                Salm...
2- Results
2- ResultsNitrogen ratio indicates trophic position                                            Carbon ratio indicates sour...
2- Results
12                Malacoceros fuliginosus             Capitella sp.                          N           11           10  ...
12                Malacoceros fuliginosus             Capitella sp.                          N           11           10  ...
2- Results: fouling organisms       9,0               Ascidiella   Colonial      Filamentous                aspersa     tu...
2- Summary• 13C and 15N are effective tracers• Benthic organisms feed on fish farm waste• Fouling organisms assimilate par...
Conclusions Increased biomass of suspension feeders (eg. Tunicates)  could decrease levels of particulate and dissolved m...
PerspectiveCould the biomass of fouling organisms be increased to increase uptake of organic material?Could benthic specie...
AcknowledgementHELP AND ADVICE•   Francis O’Beirn, Marine Institute•   Grainne O’Brein, BIM                               ...
2- ResultsCapitella capitata    Malacoceros fuliginosus
2- Results                            AnemoneCapitella capitata    Malacoceros fuliginosus
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Extent of influence of salmon farms on benthic community and trophic structure - Myriam Callier

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  • As well as the benthic samples, articifial substrata were also deployed to investigate development of fouling communities and their uptake of organic matter from the farm.
  • Deposit collected in sediment traps beneath the cages.
  • Black symbols: under cages; Grey: 25 m; white: 200m. The study showed that Ascidiella aspersa, a filter feeder, presented enriched δ15N at sites under the farms. This result indicates that tunicates efficiently filter and assimilate particulate fish waste.
  • Extent of influence of salmon farms on benthic community and trophic structure - Myriam Callier

    1. 1. Extent of influence of salmon farms on benthic community and trophic structure Myriam Callier School of Biology and Environmental Science, University College Dublin now at IFREMER, Palavas Station, FranceS. Lefebvre, K. Dunagan, M-P Bataille, J. Coughlan and T. Crowe
    2. 2. Aquaculture waste into the food web Food dissolved Excretion Secondary N 60%, P 10% consumer C 1% Primary Primary Organic producers Faeces Lost consumers matter N 15%, P 60%, C 25% Various pathwaysAssimilation of aquaculture waste by the biota (Sara et al. 2004, Lojen et al. 2005, Dolenec et al. 2007)
    3. 3. Objectives• Determine the influence of aquaculture waste on benthic communities2. Assess the contribution of aquaculture waste to benthic organisms’ diet
    4. 4. • Influence of aquaculture waste on benthic communitiesHypotheses:3. Abundance and diversity of benthic macrofauna will vary along transects leading away from salmon cages2. Benthic community structure will differ between sites located at different distances from the farm3. Extent of fish farm influence depends on residual water current direction
    5. 5. Study sitesMulroy Bay, Co. Donegal, Republic of Ireland Mulroy Bay Millstone T2 T1 Main current direction Cranford T12 km N T2
    6. 6. 1- MethodologyMillstone farm = M T1 200m T2 25m 0m 0m 25m 200m
    7. 7. 0m 25m 20 200m b b b 1- ResultsNumber of species 16 b 12 b b a a 8 a a a a 4 0Abundance per core sample M-T1 M-T2 C-T1 C-T2 300 b 225 a 150 a a a a a a 75 a a a a 0 M-T1 M-T2 C-T1 C-T2 2.5 b b 2 b b bShannon H b Diversity: lower under the cages and 25m, 1.5 in the current direction a a 1 a a a a 0.5 0 Callier et al., in M-T1 M-T2 C-T1 C-T2 revision
    8. 8. 0m 25m 20 200m b b b 1- ResultsNumber of species 16 b 12 b b a a 8 a a a a 4 0Abundance per core sample M-T1 M-T2 C-T1 C-T2 300 b 225 a 150 a a a a a a 75 a a a a 0 M-T1 M-T2 C-T1 C-T2 2.5 b b 2 b b bShannon H b 1.5 a a 1 a Abundance: no significant difference, a except Cranford, under cages a 0.5 a 0 Callier et al., in Increase based on opportunisticC-T1 M-T1 M-T2 species C-T2 revision
    9. 9. 1- Community structure Maldanidae Stress: 0.13 0m 200 mMalacoceros sp. Capitella sp. Obusa M-T1-25m C-T2-25m M-T2-25m Lucinidae C-T1-25m Organic enrichment gradient Callier et al., in revision
    10. 10. 1- Summary Localised organic enrichment due to salmon farming Effects extend < 25 m, perpendicular to current Effects extend 25-200m downstream Under cages: low diversity, high abundance of opportunistic species Are these species benefiting from the organic input ?
    11. 11. 2. Assess the contribution of aquaculture waste in the benthic organism’s dietStable isotope (SI) increasingly used to determine:• Trophic level, pathways of OM in food webs• Contribution of food sources to organisms’ dietCarbon (δ13C) and Nitrogen (δ15N) efficient tracer of salmonfood:  Compared to other sources: • Enriched in 15N as contain fish/crustacen meal (Mazzola and Sara 2001) • Depleted in 13C as contain terrestrial vegetables (wheat, soya) (Yokoyama and Ishihi, 2007)
    12. 12. 3- MethodologyArtificial substrates 200 m 25 m 0m 2 months
    13. 13. 2- MethodologySOURCES OF ORGANIC MATTER CONSUMERS Salmon Faeces Salmon Food pellet macroalgae POM- Water samples Stable isotope composition Carbon and Nitrogen
    14. 14. 2- Results
    15. 15. 2- ResultsNitrogen ratio indicates trophic position Carbon ratio indicates source of carbon
    16. 16. 2- Results
    17. 17. 12 Malacoceros fuliginosus Capitella sp. N 11 10 9 0m 25m 200m 8 * * 7 *δ13C, MT2, P<0.05 6 12 Anthopteura balii Nephtys hombergii P 11 - *δ15N (‰) 10 * * - 9 * 8 7 * δ13C, MT2, P<0.05 *δ13C, MT2, P<0.05 - δ15N, MT1, P<0.05 6 12 Lumbrineris gracilis Leptosynapta inhaenrens M
    18. 18. 12 Malacoceros fuliginosus Capitella sp. N 11 10 9 0m 25m 200m 8 * * 7 *δ13C, MT2, P<0.05 6 12 Anthopteura balii Nephtys hombergii P 11 - *δ15N (‰) 10 * * - 9 * 8 7 * δ13C, MT2, P<0.05 *δ13C, MT2, P<0.05 - δ15N, MT1, P<0.05 6 12 Lumbrineris gracilis Leptosynapta inhaenrens M
    19. 19. 2- Results: fouling organisms 9,0 Ascidiella Colonial Filamentous aspersa tunicates algae 8,5 8,0d15N 7,5 7,0 6,5 6,0 -22 -21 -20 -19 -18 -17 -16 d 13C
    20. 20. 2- Summary• 13C and 15N are effective tracers• Benthic organisms feed on fish farm waste• Fouling organisms assimilate particulate material released from fish cages
    21. 21. Conclusions Increased biomass of suspension feeders (eg. Tunicates) could decrease levels of particulate and dissolved material in the surrounding environment Potential mitigation strategy? Substrates could be used in highly sensitive environments, where small reductions in nutrient loading could be critical
    22. 22. PerspectiveCould the biomass of fouling organisms be increased to increase uptake of organic material?Could benthic species (polychaetes) be used in integrated aquaculture systems to valorise fish farm waste
    23. 23. AcknowledgementHELP AND ADVICE• Francis O’Beirn, Marine Institute• Grainne O’Brein, BIM BIM• Catherine McManus, Marine Harvest IrelandFIELD and LAB WORK• MarBEE team!• Special thanks to Julien, Paul and Silvia• Divers and staff from Marine Harvest, Mulroy Bay!FUNDING AGENCY• Environmental Protection Agency, NDP, SSTI
    24. 24. 2- ResultsCapitella capitata Malacoceros fuliginosus
    25. 25. 2- Results AnemoneCapitella capitata Malacoceros fuliginosus

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