How do you assess the health of a marine invertebrate—namely Antarctic krill—when there’s no historical baseline to measure it against?
In an intriguing piece of detective work reported in PLoS ONE a team of researchers from China and the US turned to analyzing old seal hairs to determine changes in abundance of krill in the past century.To look deeper into history, the authors analyzed core samples from lake sediments near an Antarctic fur seal colony on King George Island in the South Shetland Islands off the Antarctic Peninsula.
Their results indicate that krill began to decline in the diet of fur seals in this part of Antarctica nearly a century ago. That time frame correlates with increasing sea surface temperatures and dwindling sea ice.
http://motherjones.com/blue-marble/2011/11/seal-fur-sheds-light-antarctic-krill