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Arctic Whale Ecology Study / CHAOZ-X 2015 Cruise Report

December 06, 2015

The 2015 Arctic Whale Ecology Study (ARCWEST)/Chukchi Acoustics, Oceanography, and Zooplankton Study-extension (CHAOZ-X) cruise took place on board the F/V Aquila. The cruise began in Nome, AK on 8 September 2015 and ended in Dutch Harbor, AK on 28 September 2015. Chief Scientist was Dr. Catherine Berchok, and the survey team consisted of 11 scientists representing six different laboratories or institutions (for full personnel list, see Appendix 1). In summary, a total of 24 passive acoustic, 24 oceanographic, and 4 combination (oceanographic/passive acoustic) moorings were retrieved, and 20 passive acoustic, 13 oceanographic, and 4 combination moorings were redeployed. A total of 17 CTD casts were conducted, 133 sonobuoys were deployed for 24 hour passive acoustic monitoring, over 600 nm were surveyed for marine mammals, and over 900 nm were surveyed for seabirds.

The western Arctic physical climate is rapidly changing. The summer Arctic minimum sea ice extent in September 2012 reached a new record of 3.61 million square kilometers, a further 16% reduction from a record set in 2007 (4.30 million square kilometers). This area was more than 50% less than that of two decades ago. The speed of this ice loss was unexpected, as the consensus of the climate research community was that this level of ice reduction would not be seen for another thirty years. As sea temperature, oceanographic currents, and prey availability are altered by climate change, parallel changes in baleen whale species composition, abundance and distribution are expected (and evidenced already by local knowledge and opportunistic sightings). In addition, the observed northward retreat of the minimum extent of summer sea ice has the potential to create opportunities for the expansion of oil and gas-related exploration and development into previously closed seasons and localities in the Alaskan Arctic. It will also open maritime transportation lanes across the Arctic adding (to a potentially dramatic degree) to the ambient noise in the environment. This combination of increasing anthropogenic impacts, coupled with the steadily increasing abundance and related seasonal range expansion by bowhead (Balaena mysticetus), gray (Eschrichtius robustus), humpback (Megaptera novaeangliae) and fin whales (Balaenoptera physalus), mandates that more complete information on the year-round presence of large whales is needed in the Chukchi Sea planning area. Timing and location of whale migrations may play an important role in assessing where, when, or how exploration or access to petroleum reserves may be conducted, to mitigate or minimize the impact on protected species.

Last updated by Alaska Fisheries Science Center on 08/31/2021

Research in Alaska Cetacean Assessment and Ecology Program Marine Mammals