EESS Spring Seminar Series - Paul Koch, Professor and Dean, Physical & Biological Sciences, University of California, Santa Cruz
EESS Spring Seminar Series - Paul Koch, Professor and Dean, Physical & Biological Sciences, University of California, Santa Cruz, "Shifting Baselines on the Antarctic Coast: Using Mummies to Understand the Vulnerability of Seals to Changing Climate", Abstract: To conserve biodiversity, we need to understand the vulnerability of species or ecosystems to anticipated climate change. Vulnerability is a function of exposure to climate change, sensitivity to the forcing, and adaptive capacity. Paleoecological records of the response of species or ecosystems to past climate shifts may provide critical insights into sensitivity and adaptability. I'll explore these issues for southern elephant seals, a high latitude species that will be exposed to large climatic and oceanic changes in the coming centuries. While they are extremely rare in the region today, southern elephant seals occurred along much of the southwestern coast of the Ross Sea, Antarctica, from 7000 to just 500 years ago. Elephant seals are scarce in the region today because land can only be accessed by passage over large, land-fast ice shelves. The presence of elephant seals, as well as raised beaches formed by wave action, indicate that the western Ross Sea coast lacked such shelves for much of the Holocene. My colleagues and I have explored the response of elephant seals to this major environmental change. We used ancient DNA to reconstruct shifts in seal abundance, stable isotopes to understand changes in seal foraging ecology and Ross Sea oceanography, and osteometrics to understand population characteristics. I'll explore the environmental factors beyond the change in ice shelves that may be driving changes in elephant seal ecology and Ross Sea oceanography. I'll end by considering what the response of southern elephant seals implies about their vulnerability to future climate change and offer a few highlights from our ongoing work on mummies from three seals that are still common in the Ross Sea today - crabeater seals, leopard seals, and Weddell seals.