Antarctic Food Web

Krill in Antarctic Food Webs

Phytoplankton

Krill Swarms

Phytoplankton

Antarctic Circumpolar Current (ACC)

The WAP is the location where the ACC is closest to the continent

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

Qs

lop

e (

x109

J m

-2)

°CIncrease of 6°C in the past 50 years

50-year changes in winter air temperature

Hea

t con

tent

(x10

9 J m

-2) Seawater heat content

Questions?

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

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

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

Recent changes in Adélie PenguinsRecent changes in Adélie Penguins

• Decrease in Adélie penguins, increases in subpolar species Adélie penguins, increases in subpolar species (Gentoos, Chinstraps)(Gentoos, Chinstraps)

Line 600 (north)

Questions?