1. Antarctic Food Web

3. Krill in Antarctic Food Webs Phytoplankton

4. Krill Swarms Phytoplankton

5. Antarctic Circumpolar Current (ACC) The WAP is the location where the ACC is closest to the continent

6. Using the WAP as zone to study how rapid warming can alter food webs Fastest winter warming location on Earth Increase in ocean heat content Martinson et al. 2008 Q slope (x10 9 J m -2 ) °C Increase of 6°C in the past 50 years 50-year changes in winter air temperature Heat content (x10 9 J m -2 ) Seawater heat content

7. Questions?

8. 100 μm Recent rapid warming at WAP reverberates through the food web Declines in phytoplankton and shift to small cell size that krill can not feed on (but salps can) Declines in nutritious Antarctic krill; increase in much less nutritious gelatinous salps Declines in krill and ice-dependent Adélie penguins, but increases in subpolar (warmer adapted) species, Gentoo and Chinstraps, that can dive deep and eat deep-water fish 10 μm

9. 100 μm Recent rapid warming at WAP reverberates through the food web Declines in phytoplankton and shift to small cell size that krill can not feed on (but salps can) Declines in nutritious Antarctic krill; increase in much less nutritious gelatinous salps Declines in krill and ice-dependent Adélie penguins, but increases in subpolar (warmer adapted) species, Gentoo and Chinstraps, that can dive deep and eat deep-water fish 10 μm

10. 100 μm Recent rapid warming at WAP reverberates through the food web Declines in phytoplankton and shift to small cell size that krill can not feed on (but salps can) Declines in nutritious Antarctic krill; increase in much less nutritious gelatinous salps Declines in krill- and ice-dependent Adélie penguins, but increases in subpolar (warmer adapted) species, Gentoo and Chinstraps, that can dive deep and eat deep-water fish 10 μm

11. Recent changes in Adélie Penguins Salinity (p.p.t) % Cryptophytes 02550 33.333.633.8 64°W Palmer Station Antarctic Peninsula 65°S Adélie penguins, increases in subpolar species (Gentoos, Chinstraps) Decrease in Adélie penguins, increases in subpolar species (Gentoos, Chinstraps) Line 600 (north)

12. Questions?