OBSOLETE: Marine Mammals: At the intersection of ice, climate change and human interactions

Abstract

Marine mammals (whales (cetaceans), seals (phocids), sea lions (otariids), walrus ( Odobenus rosmarus ), sea otters ( Enhydra lutris ), and polar bears ( Ursus maritimus )) inhabit almost all oceanic regions of the Arctic and subarctic. Many of these species are dependent on sea ice to raise their young, hunt, rest, and avoid predators. As the sea ice in the Arctic changes with the climate, the availability of this ice platform has decreased throughout the year. Consequently, the distribution and health of many ice-dependent marine mammal species is also changing. Because marine mammals are “warm-blooded” and can regulate their internal body temperature, the absolute temperature of the seawater is not as important to them as the impact of temperature on the sea ice itself and to their prey. Seawater temperature is tightly linked to the distribution of fish and other marine mammal prey (plankton, squid, etc.). Therefore, as the temperature of the water changes, the distribution of prey may also change. Further, the interaction of humans with marine mammals, either through commercial fishing, direct indigenous hunting, increased industrial ship traffic, or tourism, will also change as the mammals alter their own locations and the Arctic Ocean “opens up” from ice thaw. This cascading impact (warmer seawater temperatures, less sea ice, distribution of prey, impact to breeding success, and changes in human interactions) has led some polar marine mammal species to be placed on protected or endangered species lists (e.g., polar bear).