Bering Sea | Mammals
Increasing algal toxin exposure risks in Pacific walruses ( Odobenus rosmarus ) in the northern Bering Sea Presenter: Kathi Lefebvre , kathi.lefebvre@noaa.gov, Northwest Fisheries Science Center (NOAA) Gay Sheffield , ggsheffield@alaska.edu, University of Alaska Fairbanks
Emily Bowers , emily.bowers@noaa.gov, NOAA Northwest Fisheries Science Center Evie Fachon , efachon@whoi.edu, Arctic Research Consortium of the United States Donald Anderson , danderson@whoi.edu, Woods Hole Oceanographic Institution Patrick Charapata , patrick.charapata@noaa.gov, NOAA Northwest Fisheries Science Center Jonathan Snyder , jonathan_snyder@fws.gov, U.S. Fish and Wildlife Service
Climate change-related ocean warming and continued reduction in Arctic sea ice extent, duration and thickness increase the risk of toxic blooms of the dinoflagellate Alexandrium catenella in the Alaskan Arctic. This algal species produces neurotoxins that impact marine wildlife health and cause the human illness known as paralytic shellfish poisoning (PSP). PSP toxins consist of saxitoxin (STX) and its derivatives and are known to impact mammalian systems via direct blockage of voltage-gated sodium channels resulting in paralysis. Recent surveys have shown high concentrations of STXs in food webs in the northern Bering Sea where Pacific walruses are known to feed. NOAAs Wildlife Algal-toxins Research and Response Network (WARRN-West) is a coast wide surveillance network that tests for the presence of algal toxins in marine mammals that are dead, stranded, or harvested for subsistence purposes. STXs have been detected in walrus fecal samples in most years since the first sampling began in 2010 indicating that at least background exposure has occurred for the last decade. Recent evidence for more frequent, larger, and more toxic blooms in a warming Arctic by our research team suggests that STX exposures to walruses may be increasing as toxin presence increases in the food web. Here we will present findings on STX prevalence, estimated doses, and tissue distribution in walruses that will be useful for assessing both animal and human health risks for this critically important resource for Arctic communities.
Alaska Marine Science Symposium 2023 54
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