Marine Mammals and Oceanography in the‘New Normal’ Pacific Arctic

Extreme sea ice retreats can influence the phenology of marine mammals in the Pacific Arctic.  For example, walruses now often haul out by the thousands along the NW Alaska coast in late summer, and summertime reports of harbor porpoise, humpback, fin and minke whales in the Chukchi Sea suggest these temperate species now routinely occur there.  In 2010, satellite tagged bowhead whales from Atlantic and Pacific populations met in the Northwest Passage, an overlap thought precluded by sea ice since the Holocene.  Arctic climate continues to change more than twice as fast than at lower latitudes
due to coupled positive feedback processes.  Extensive ice-free regions now occur each year in the Pacific Arctic sector, with record-low sea ice extents in 2007 and 2012. Sea ice thickness continues to decrease, while autumn temperatures increase, suggesting that the Arctic climate system has reached a ‘New Normal’ state.  Concurrently, lower trophic level plankton and benthic fauna are responding to the ‘new’ environmental forcing at variable time and space scales.  Changes to these prey populations can have energetic impacts to upper trophic level predators, as well as alter trophic transfer of biotoxins and contaminants.  In addition, increasing offshore anthropogenic activities can alter marine mammal exposure and response to infectious disease, underwater sound and potential trauma from ship strikes.  Two new programs, the Distributed Biological Observatory (DBO) and the Synthesis of Arctic Research (SOAR), include tracking of marine mammal and lower level prey base responses to ecosystem shifts associated with sea ice loss.  Both programs can provide an environmental base to a Marine Mammal Health Mapping program, envisioned as a component of the U.S. Integrated Ocean Observing System (IOOS).   An overarching goal is to identify ‘New Normal’ patterns for marine mammals, as a foundation for integrative research, local response and adaptive management.