Climate and the Arctic Calanus complex
Transcription
Climate and the Arctic Calanus complex
Climate and the Arctic Calanus complex Stig Falk-Petersen, Haakon Hop, Eva Leu, A Wold Norwegian Polar Institute and Janne Søreide, Jørgen Berge, UNIS Sun dogs, the Amundsen Gulf, minus 40 degrees C Arctic Change, Quebec, December 2008 Content 1. IPY Calanus activity 2. Climate change takes place on all (time) scales 3. Ecosystem ( Calanus) adaptation to climate change PAN-AME (IPY-26) The productive Arctic Arctic observatories North of Nordaustlandet Amundsen Gulf http://www.nfh.uit.no/arctos Climate swings, decades and longer Record northerly (82°N) location of the ice edge in autumn 2004 and 2007 not 8 3 since 1751 observed 2004 82 * 81 1658 Carl 10. Gustav Latitude 80 79 78 77 76 75 Y ear White line = August ice boarder position 10 year mean Blue bars = open water Red line = Deviation from the Northern Hemisphere Vinje 1999 mean temperature Falk-Petersen et al. 2008 00 20 19 80 60 19 40 19 20 19 00 19 80 18 60 18 40 18 20 18 00 18 80 17 60 17 40 17 20 17 00 17 80 16 60 16 40 16 20 16 00 16 15 80 74 Extreme April (winter) ice location. Area available for “spring blooms” Whalers Bay Svalbard Bjørnøya No rw ay Gre enla nd Zemlja Franca Iosifa Østerhus 98/10 1769 1866 1966 1995 Torgny Vinje Climate swings between years August 2007 versus 2008 The concept of the Arctic phytoplankton bloom (ice cover modifies light available) Falk-Petersen et al. (2008) Arctic Calanus The most important animals in high latitude seas: Calanus species are converting low energy sugar to high energy animal fat Did climate change create Calanus? Diatoms and Calanus The Cenozoic record of diatoms and the appearance of the copepod super families (Calanus) occurred 65 MYA and coincides with • expansion of the polar ice cap • cooling of the ocean • thermohaline circulation • seasonality of production The Arctic Calanus The genus Calanus is engineered to: 1) feed on pulses of energy 2) convert low energy sugars to a high energy lipids 3) store energy in strongly pulsed systems. This is further support by a unique biosynthetic pathway which lead to the formation of wax ester Arctic Calanus • Our hypotheses is that the timing of the bloom determines the life strategy of the individual species and biodiversity of the Arctic Calanus complex • The Arctic Calanus herbivores has adapted to climate variability: – as individuals by accumulating energy reserves (lipids) – as “species” by developing different life strategy Copepod life histories Summer Winter Winter Surface waters (0-200m) Deep (1000-2000m) What will happen if the sea was ice covered? Øystein Varpe Life cycle strategy Falk-Petersen et al. 2007, 2008 Growth of the different copepodite stages Falk-Petersen et al. 2007 Size and lipid content C. hyperboreus C. hyperboreus is 2 times longer than C. finmarchicus Calanus hyperboreus has 26 and C. glacialis 10 times as much energy as C. finmarchicus C. glacialis C. finmarchicus Arctic bloom and Calanus • Calanus finmarchicus is a deep-water species adapted a regular yearly spring bloom => the Norwegian Sea • Calanus glacialis is a shelf species adapted to large variations in the timing and length of the annual bloom => northern Barents Sea, Siberian and American shelves • Calanus hyperboreus is a deepwater species adapted to large interannual variations in ice cover and algal blooms => central Arctic Ocean, Greenland Sea and Fram Strait Falk-Petersen et al. 2008 FOOD WEB SCENARIO – CLIMATE CHANGE Cold period Favor Arctic species: C. glacialis Sufficient energy for little auk Falk-Petersen et al., 2007 Warm period Favor Atlantic species: C. finmarchicus Small and less lipids-rich ⇒ No little auk iIcrease in pelaic fish and minkewhale Ongoing research on the Arctic Calanus complex • Climate effects on food quality and trophic transfer • Timing of primary production relative to the ice break up • Food quality changes in ice algae and phytoplankton over time • Timing of the seasonal ascent / descent of Calanus • Food sources (quality) available for Calanus (glacialis) during the reproductive development? • Food chain energy transfer