A bi-polar perspective on sea ice

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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.

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Outline

1. Differences and similarities between the Polar Regions 2. Productivity

3. Biodiversity

4. Climate change

5. Conclusions

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PACES II

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

Topic 1: Changes and regional feedbacks in Arctic and Antarctic

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Biogeochemical cycling in Polar ecosystems

Identify the processes that link physics, chemistry and biology

Atmosphere

Lithosphere

Biosphere

Respiration

Photosynthesis Hydrosphere

Cryosphere

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Atmosphere

Lithosphere

Biosphere

Respiration

Photosynthesis Hydrosphere

Cryosphere

Biogeochemical cycling in Polar ecosystems

Identify the processes that link physics, chemistry and biology

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Global sea surface temperature

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Global sea SST and sea ice zones

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Differences in hydrography

Arctic Ocean Antarctic Ocean

• Open ring ocean

• 20 mio skm SIZ

• Narrow, deep shelves

• Circum-Polar currents

• High nutrient concentrations

• Iron-limited

• Mediterrenean ocean

• 16 mio skm SIZ

• Broad, shallow shelves

• Trans-polar currents

• Low nutrient

concentrations

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Differences in sea ice

Arctic Ocean Antarctic Ocean

• FYI dominant

• Snow cover

• Ice shelves

• Platelet ice habitats

• MYI dominant (?)

• Little snow

• Melt ponds

• Aggregates / Melosira

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What to compare?

Young et al. (2011)

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What to compare?

Young et al. (2011)

Arctic Antarctic Neritic Shallow

+ Nuts + iron MYI

Deep

+ nuts, (+ iron) MYI Ice shelves

Oceanic Deep

- nuts + iron MYI -> FYI

Deep

+ nuts – iron

FYI

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Phytoplankton, ice algae

Copepods, amphipods

Myctophids, squid

Seabirds, penguins, seals, whales

Krill

Antarctic oceanic

Phytoplankton, ice algae, Melosira

Copepods, (ice) amphipods

Polar cod, Capelin, herring

Seabirds, seals, whales, polar bear

Arctic

neritic

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Polar cod, Capelin, herring

Seabirds, seals, whales, polar bear

Copepods, (ice) amphipods,

ice krill

P. antarcticum, P. borchgrevinki

Arctic neritic

Antarctic

neritic

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Polar cod

Seabirds, seals, polar bear

Arctic oceanic

Copepods, amphipods, salps

Myctophids, squid

Krill

Antarctic

oceanic

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Productivity

Arctic Ocean Southern Ocean

Arrigo et al. (2008) J Geophys Res Arrigo et al. (2008) Geophys Res Lt

Max.

sea ice extent

Annual water column primary production (g C m

^-2

y

^-1

)

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Productivity

Arctic Ocean Southern Ocean

Max.

sea ice extent

~ 500

TgC a

^-1

~ 1950

TgC a

^-1

Annual water column primary production (g C m

^-2

y

^-1

)

Arrigo et al. (2008) Geophys Res Lt Arrigo et al. (2008) J Geophys Res

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Productivity

Arctic Ocean Southern Ocean

Max.

sea ice extent

~ 500 TgC a

^-1

Annual water column primary production (g C m

^-2

y

^-1

)

~ 180

TgC a

^-1

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Arctic Ocean Southern Ocean

Max.

sea ice extent

~ 500 TgC a

^-1

Annual water column primary production (g C m

^-2

y

^-1

)

~ 180 TgC a

^-1

** Arrigo & Thomas (2004) Ant Sci McMinn et al. (2010) Mar Biol

*Gosselin (1997) Deep-Sea Res II

≤ 57 % ?* 10-65 % ?**

Proportional contribution of ice algal primary

production

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Primary production in the Arctic SIZ

Mar Fernandez-Méndez

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Antarctic sea ice algal biomass

Meiners et al. (2012) Geoph. Res. Let.

Klaus Meiners

Gerhard Dieckmann

Flores et al. (2012) Mar. Ecol. Prog. Ser.

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Diversity

0 2000 4000 6000 8000 10000

Arctic Ocean Antarctic Ocean*

No of animal taxa

Other taxa Crustaceans

Census of Marine Life database (2013)

* South of 60°S

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Under-ice fauna

0 20 40 60

Arctic Ocean Lazarev Sea*

No of taxa

Hauke Flores Carmen David Henrieke Tonkes

*Flores et al. (2011) Deep-Sea Res. II

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Under-ice fauna

Carmen David Hauke Flores

*Flores et al. (2011) Deep-Sea Res. II

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Under-ice fauna

Carmen David, Benjamin Lange

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Arctic phytoplankton communities

Estelle Kilias Arctic Ocean, 2011

Taxonomical groups identified by 18S rDNA variability(454 pyrosequencing)

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Ammundsen Sea (SO), 2010

Wolf et al. (in press) Ant. Sci.

Christian Wolf

Antarctic phytoplankton communities

Taxonomical groups identified by 18S rDNA variability(454 pyrosequencing)

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Community analysis

Arctic Ocean 2012

Arctic Ocean 2011

Phytoplankton

Under-ice fauna Under-ice fauna

Under-ice fauna

Lazarev Sea 2007/08

Carmen David Benjamin Lange Hauke Flores Estelle Kilias

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Arctic Ocean climate change

Leu et al. (2011); Wassman et al. (2011)

Sea ice concentration trend 1979-2011

National Snow and Ice data Center (2011) http://nsidc.org

September

‚historical‘ sea New ice minimum

in 2012

• Decline of sea ice extent

• Loss of MYI

• Ocean warming

• Acidification

• ‘Atlantification’

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Kraft et al. (in review), Mar. Ecol. Prog. Ser.

Abundance index [ind. m-2 d-1 ]

absent

First appearance in July 2004

First evidence of propagation in

August 2011

Themisto compressa

Angelina Kraft

An ‘Atlantic’ species in the Arctic

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Krill Salps

Sea ice

Temperature

^cold ^warm

• Regionally different sea ice change

• Ocean warming

• Acidification

• Species range shift

After Loeb et al. (1997), Atkinson et al. (2004)

Antarctic Ocean Climate Change

Flores et al. (2012) Mar. Ecol. Prog. Ser.

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Overwintering of krill larvae

Better growth in sea ice Winter diet: heterotrophic sea ice biota

Meyer et al. (2009), L&O Bettina Meyer

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Molecular research on sea ice algae

Neg.

control

AFPs

100 μm

Bayer-Giraldi et al., 2011

Fragilariopsis cylindrus nana

Transcriptome analysis Function of anti-freeze proteins (AFP)

Anique Stecher

Maddalena Bayer-Giraldi

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• Bathymetry

• Topographic isolation

• Stratification & currents

• Nutrient regime

• Sea ice properties

• Diversity

• Presence of sea ice

• Cold temperatures

• Pronounced seasonality

• Chemically limited PP

• Organism adaptations

• Rapid environmental change

Differences Similarities

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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

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Multi-disciplinary surveys

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Linking datasets

Carbon export

Physical sea ice

properties Under-ice

community Primary production

Catherine Lalande Mar Fernandez-Méndez

Benjamin Lange Carmen David

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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

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