Using Bowhead Whales as a Multi‐Decadal Contaminant Recorder in a Warming Arctic

Grant Winners

Dean

Abstract

The western Arctic bowhead whale migrates annually along the edge of the Arctic Ocean, incorporating environmental contaminants via diet into their tissues. Natural and anthropogenic contaminants include heavy metals, both essential and  non-essential, to biological organisms. Melting sea ice and thawing coastal permafrost releases historically deposited contaminants into the marine environment which accumulate in marine organisms and, subsequently, humans reliant upon the marine ecosystem for their food. Heavy metals are archived in baleen as it continuously grows. Baleen is the keratinous, filter feeding apparatus which provides a multi-decadal timeline of whale diet and migration. This timeline offers insight into the general location of heavy metals as the bowhead whales migrate from the Bering Sea in early spring, through the Chukchi Sea, and eastward to the Beaufort Sea. The whales then spend the summer foraging on lipid-rich zooplankton before seasonal sea ice prompts their return route to the Bering Sea where they overwinter. Heavy metals in the whales' prey are accumulated in the baleen across both latitude and longitude over the span of each year. Anticipated fluctuations in heavy metals across five decades are expected as the Arctic environment has, and continues, to undergo rapid and drastic changes. Baleen from subsistence-harvested whales collected along their migration route contains data spanning the years 1947 to 1999. Preliminary data have confirmed detection of several heavy metals (Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Se, V, Zn) in varying concentrations along the bowhead whale baleen. These values indicate fluctuations in metal concentrations both spatially and temporally. The resulting baseline heavy metal data from this research will ultimately provide a guide for future comparisons in toxicological and environmental pollution research. By understanding how the marine Arctic is environmentally changing, we can better predict and prepare for a global solution.