Northwest Fisheries Science Center

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Document Type: Journal Article
Center: NWFSC
Document ID: 8479
Title: Prevalence of algal toxins in Alaskan marine mammals foraging in a changing arctic and subarctic environment
Author: Kathi A. Lefebvre, Lori Quakenbush, Elizabeth Rose Frame, Kathy Burek Huntington, Gay Sheffield, Raphaela Stimmelmayr, Anna Bryan, Preston Kendrick, Heather Ziel, Tracey Goldstein
Publication Year: 2016
Journal: Harmful Algae
Volume: 55
Issue: 2016
Pages: 13-24
Keywords: harmful algal bloom,toxins,domoic acid,saxitoxin,marine mammals,Alaska
Abstract:

Current climate trends including rapid declines in sea ice and increasing water temperatures are likely to expand the northern geographic range and duration of favorable conditions for harmful algal blooms (HABs), making algal toxins a growing concern in the Alaskan marine food web.  Two of the most common HAB toxins on the west coast of North America are the neurotoxins domoic acid (DA) and saxitoxin (STX).  Over the last 25 years, DA toxicosis has caused significant illness and mortality in marine mammals along the southwest coast of North America, but has not been reported to impact marine mammals foraging in Alaskan waters.  Saxitoxin, the most potent of the paralytic shellfish poisoning toxins, has been well-documented in Alaskan shellfish for decades and although human illnesses and deaths due to consumption of toxic clams have been reported, there is little information regarding exposure of Alaskan marine mammals.  Here, we document the spatial patterns of DA and STX exposure in Alaskan marine mammals, to assess health risks to northern populations including those species that are important to the nutritional, cultural, and economic wellbeing of Northern and Western Native Alaskan communities.  We sampled approximately 900 marine mammals from 13 species, including four species of cetaceans (humpback whale Megaptera novaeangliae, bowhead whale Balaenidae mysticetus, beluga whale Delphinapterus leucas, and harbor porpoise Phocoena phocoena), two species of otariids (northern fur seal Callorhinus ursinus and Steller sea lion Eumetopias jubatus), five species of phocids (harbor seal Phoca vitulina, ringed seal Phoca hispida, bearded seal Erignathus barbatus, spotted seal Phoca largha, and ribbon seal Histriophoca fasciata), Pacific walruse Obodenus rosmarus, and Northern sea otter Enhydra lutra.  Domoic acid was detected in all 13 species examined and had the greatest percent occurrence in bowhead whales and harbor porpoises at 68% and 67%, respectively.  Saxitoxin was detected in 10 of the 13 species examined and had the highest percent occurrence in humpback and bowhead whales at 50% and 32%, respectively.  Pacific walruses contained the highest concentrations of both STX and DA, with DA concentrations similar to those detected in California sea lions exhibiting clinical signs of DA toxicosis (seizures) in Central California, USA.  Thirty-six individuals contained detectable concentrations of both toxins emphasizing the potential for combined exposure risks.  Additionally, beluga, harbor porpoise and Steller sea lion fetuses contained detectable concentrations of DA documenting the potential for maternal toxin transfer.  These data provide evidence that HAB toxins may be an increasingly important factor for marine mammal health in the warming Arctic environment.

Description:

This paper characterizes the presence of harmful aglal bloom toxins in Alaskan marine mammals.

URL1: The next link will exit from NWFSC web site https://doi.org/10.1016/j.hal.2016.01.007
Theme: Ecosystem approach to improve management of marine resources
Foci: Understand how climate influences ecosystem variability.
Characterize ecological interactions (e.g. predation, competition, parasitism, disease, etc.) within and among species.