Polar FoodwebsAntarctic Pelagic Foodwebs

Anton Van de PutteRoyal Belgian Institute for Natural Sciences

www.biodiversity.aq

Who am I

• Zoologist

• PhD on the ecology and evolution of Southern Ocean fish

• Science Officer Biodiversity.aq

‘Classical view’

• a spatial homogeneous and simple food chain• Krill centred

© Philipp Assmy © Volker Siegel © Ulrich Peter

Temporal and spatial heterogeneity

AADC, Ben Raymond through share.biodiversity.aq

Chla, summer Temperature , winter Temperature , summer

Pelagic Bioregions

Grant et al., 2006

Antarctic ecosystems are changing

Atkinson et al. 2008

Antarctic Polar Front

Grant et al., 2006

e.g. Rodhouse & White, 1995

Shelf Zone

Grant et al., 2006

e.g. Thomas & Greene, 1998

Marginal Ice zone

Grant et al., 2006

e.g. Hopkins et al., 1993

Identify trophic links

• Gut content analysis– snapshot

• Stable isotopes/Fatty acid composition– Integrated over time

• Barcoding/high throughput sequencing– snapshot

Deagle 2009, Brown et al. 2012, O'Rorke et al. 2012

Barcoding/high throughput sequencing

• Barcoding: use of ‘standardised’ sequence– COI, 16S..– Still requires different

primers

• High throughput sequencing– High volume of data – Semi quantitative

Suz Bateson, University of Guelph

Quantify various trophic levels

• Energetic content• Abundance/Biomass• Productivity

Energy Content

Van de Putte, 2008

Occurrence

• Krill base – occurrence/length frequency

• SCAR-Marbin– Marine biodiversity

• Biodiversity.aq– Marine & terrestrial biodiversity

Understand food webs

• Modelling– Distribution• GLM, GAM, BRT…

– Foodweb• Eg ecopath

Flores et al. 2008

Hill et al. 2012

Example of a project structure

Questioning the Krill importance

• Copepods – same biomass– more productive

• Lanternfish – biomass

underestimated– High energy content

• Under certain circumstances important alternative

Interesting reads

• Atkinson, A., Siegel, V., Pakhomov, E., Rothery, P., 2004. Long-term decline in krill stock and increase in salps within the Southern Ocean. Nature 432 (7013), 100-103.

• Barrera-Oro, E., 2002. The role of fish in the Antarctic marine food web: differences between inshore and offshore waters in the southern Scotia Arc and west Antarctic Peninsula. Antarctic Science 14 (4), 293-309

• BROWN, D. S., JARMAN, S. N. and SYMONDSON, W. O. C. (2012), Pyrosequencing of prey DNA in reptile faeces: analysis of earthworm consumption by slow worms. Molecular Ecology Resources, 12: 259–266. doi: 10.1111/j.1755-0998.2011.03098.x

• DEAGLE, B. E., KIRKWOOD, R. and JARMAN, S. N. (2009), Analysis of Australian fur seal diet by pyrosequencing prey DNA in faeces. Molecular Ecology, 18: 2022–2038. doi: 10.1111/j.1365-294X.2009.04158.x

• Flores, H., Van de Putte, A. P., Volker, S., Pakhomov, E.A., Van Franeker J.A., Meesters, E., Volckaert, F.A.M., 2008. Distribution, abundance and ecological relevance of pelagic fish in the Lazarev Sea, Southern Ocean. Marine Ecology Progress Series.

• Grant, S., Constable, A., Raymond, B., Doust, S., 2006. Bioregionalisation of the Southern Ocean: Report of Exports Workshop. WWF-Australia and ACR CRC, Hobart, September 2006.

• Hill et al. 2012 A Foodweb Model to explore uncerteinties in the South Georgia shelf Pelagic Ecosystem. Deep Sea Research II, 59-60, 237-252.

• Hopkins, T.L., Ainley, D.G., Torres, J.J., Lancraft, T.M., 1993. Trophic structure in open waters of the marginal ice zone in the Scotia-Weddell confluence region during spring (1983). Polar Biology 13 (6), 389-397.

• O'Rorke R, Lavery S, Chow S, Takeyama H, Tsai P, et al. (2012) Determining the Diet of Larvae of Western Rock Lobster (Panulirus cygnus) Using High-Throughput DNA Sequencing Techniques. PLoS ONE 7(8): e42757. doi:10.1371/journal.pone.0042757

• Rodhouse, P.G., White, M.G., 1995. Cephalopods occupy the ecological niche of epipelagic fish in the Antarctic Polar Frontal Zone. Biological Bulletin 189 (2), 77-80.

• Thomas, P.B., Green, K., 1988. Distribution of Euphausia crystallorophias within Prydz Bay and its importance to inshore the marine ecosystem. Polar Biology 8, 327-331.