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A Bi-Polar Perspective on Sea Ice H

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A Bi-Polar Perspective on Sea Ice H A bi-polar perspective on sea ice H. Flores, C. David, B. Lange, M. Fernandez-Méndez, M. Bayer, E. Kilias, C. Wolf, C. Lalande, I. Peeken, B. Meyer, G. Dieckmann, a.m.o. Outline 1. Differences and similarities between the Polar Regions 2. Productivity 3. Biodiversity 4. Climate change 5. Conclusions PACES II Topic 1: Changes and regional feedbacks in Arctic and Antarctic WP 4 • To provide evidence and understanding of the causes and consequences of variation in sea ice cover for the hydro-, bio- and geosphere of the Arctic Ocean and beyond WP 5 • Assess the changes that occur in the Southern Ocean, identify the processes that link physics, chemistry and biology, and determine the feedback mechanisms to the global climate system Biogeochemical cycling in Polar ecosystems Identify the processes that link physics, chemistry and biology Atmosphere Cryosphere Photosynthesis Biosphere Hydrosphere Respiration Lithosphere Biogeochemical cycling in Polar ecosystems Identify the processes that link physics, chemistry and biology Atmosphere Cryosphere Photosynthesis Biosphere Hydrosphere Respiration Lithosphere Global sea surface temperature Global sea SST and sea ice zones Differences in hydrography Arctic Ocean Antarctic Ocean • Mediterrenean ocean • Open ring ocean • 16 mio skm SIZ • 20 mio skm SIZ • Broad, shallow shelves • Narrow, deep shelves • Trans-polar currents • Circum-Polar currents • Low nutrient • High nutrient concentrations concentrations • Iron-limited Differences in sea ice Arctic Ocean Antarctic Ocean • MYI dominant (?) • FYI dominant • Little snow • Snow cover • Melt ponds • Ice shelves • Aggregates / Melosira • Platelet ice habitats What to compare? Young et al. (2011) What to compare? Arctic Antarctic Neritic Shallow Deep + Nuts + iron + nuts, (+ iron) MYI MYI Ice shelves Oceanic Deep Deep - nuts + iron Young+ nuts et al. – (2011) iron MYI -> FYI FYI Seabirds, seals, Arctic whales, polar bear neritic Polar cod, Capelin, herring Copepods, (ice) amphipods Phytoplankton, ice algae, Melosira Seabirds, penguins, seals, whales Myctophids, squid Copepods, Krill amphipods Antarctic Phytoplankton, ice algae oceanic Seabirds, seals, Seabirds, penguins, Arctic whales, polar bear seals, whales neritic Polar cod, P. antarcticum, Capelin, herring P. borchgrevinki Copepods, Copepods, (ice) amphipods, (ice) amphipods ice krill Antarctic Phytoplankton, Phytoplankton, ice algae, Melosira ice algae neritic Seabirds, seals, Seabirds, penguins, Arctic polar bear seals, whales oceanic Myctophids, Polar cod squid Copepods, Copepods, Krill (ice) amphipods amphipods, salps Antarctic Phytoplankton, Phytoplankton, ice algae, Melosira ice algae oceanic Productivity Arctic Ocean Southern Ocean Max. sea ice extent Arrigo et al. (2008) Geophys Res Lt Arrigo et al. (2008) J Geophys Res Annual water column primary production (g C m-2 y-1) Productivity Arctic Ocean Southern Ocean ~ 500 Max. ~ 1950 TgC a-1 sea ice TgC a-1 extent Arrigo et al. (2008) Geophys Res Lt Arrigo et al. (2008) J Geophys Res Annual water column primary production (g C m-2 y-1) Productivity Arctic Ocean Southern Ocean ~ 500 Max. ~ 180 TgC a-1 sea ice extent TgC a-1 Arrigo et al. (2008) Geophys Res Lt Arrigo et al. (2008) J Geophys Res Annual water column primary production (g C m-2 y-1) Proportional contribution of ice algal primary production Arctic Ocean Southern Ocean ~ 500 Max. ~ 180 TgC a-1 sea ice extent TgC a-1 ≤ 57 % ?* 10-65 % ?** Arrigo et al. (2008) Geophys Res Lt Arrigo et al. (2008) J Geophys Res *Gosselin (1997) Deep-Sea Res II ** Arrigo & Thomas (2004) Ant Sci McMinn et al. (2010) Mar Biol Annual water column primary production (g C m-2 y-1) Primary production in the Arctic SIZ Mar Fernandez-Méndez Flores et al. (2012) Mar. Ecol. Prog. Ser. Antarctic sea ice algal biomass Klaus Meiners Gerhard Dieckmann Meiners et al. (2012) Geoph. Res. Let. Diversity 10000 8000 6000 Other taxa 4000 Crustaceans No of animalof taxa No 2000 0 Arctic Ocean Antarctic Ocean* * South of 60°S Census of Marine Life database (2013) Under-ice fauna No of taxa 60 40 20 Hauke Flores 0 Carmen David Arctic Ocean Lazarev Sea* Henrieke Tonkes *Flores et al. (2011) Deep-Sea Res. II Under-ice fauna Carmen David Hauke Flores *Flores et al. (2011) Deep-Sea Res. II Under-ice fauna Carmen David, Benjamin Lange Arctic phytoplankton communities Arctic Ocean, 2011 Estelle Kilias Taxonomical groups identified by 18S rDNA variability(454 pyrosequencing) Antarctic phytoplankton communities Christian Wolf Ammundsen Sea (SO), 2010 Taxonomical groups identified by 18S rDNA variability(454 pyrosequencing) Wolf et al. (in press) Ant. Sci. Community analysis Arctic Ocean 2012 Under-ice fauna Under-ice fauna Carmen David Lazarev Sea Benjamin Lange 2007/08 Hauke Flores Estelle Kilias Arctic Ocean 2011 Under-ice fauna Phytoplankton National Snow and Ice data Center (2011) http://nsidc.org Arctic Ocean climate change Sea ice concentration trend 1979-2011 New ‚historical‘ sea ice minimum September in 2012 • Decline of sea ice extent • Loss of MYI • Ocean warming • Acidification Leu et al. (2011); Wassman et al. (2011) • ‘Atlantification’ Themisto compressa An ‘Atlantic’ species in the Arctic Angelina Kraft ] First evidence of 1 - d propagation in 2 - August 2011 . m First appearance in July ind [ 2004 index absent Abundance Kraft et al. (in review), Mar. Ecol. Prog. Ser. Flores et al. (2012) Mar. Ecol. Prog. Ser. Antarctic Ocean Climate Change Sea ice Salps • Regionally different sea ice change Krill • Ocean warming • Acidification cold warm Temperature • Species range shift After Loeb et al. (1997), Atkinson et al. (2004) Overwintering of krill larvae Bettina Meyer Better growth in sea ice Winter diet: heterotrophic sea ice biota Meyer et al. (2009), L&O Molecular research on sea ice algae Bayer-Giraldi et al., 2011 Fragilariopsis cylindrus nana Neg. control Maddalena Bayer-Giraldi 100 μm AFPs Function of anti-freeze proteins (AFP) Transcriptome analysis Anique Stecher Differences Similarities • Bathymetry • Presence of sea ice • Topographic isolation • Cold temperatures • Stratification & currents • Pronounced seasonality • Nutrient regime • Chemically limited PP • Sea ice properties • Organism adaptations • Diversity • Rapid environmental change Conclusions • Sea ice system still poorly understood • Complementary approaches allow to identify and compare drivers of change and ecosystem response in both Polar Oceans • Both empirical and mechanistic studies are needed to understand the processes of change in Polar systems Multi-disciplinary surveys Primary production Carbon export Mar Fernandez-Méndez Linking datasets Catherine Lalande Physical sea ice Under-ice properties community Benjamin Lange Carmen David Conclusions AWI‘s biological sea ice research combines long-term experience, scientific skills and modern approaches to address the complexity of future change at both Poles Internal and external collaboration and inter- disciplinarity are key to enhance scientific impact Thank you .
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