Publication Date:
2022-07-15
Description:
© The Author(s), 2022. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Lefebvre, K., Fachon, E., Bowers, E., Kimmel, D., Snyder, J., Stimmelmayr, R., Grebmeier, J., Kibler, S., Hardison, D., Anderson, D., Kulis, D., Murphy, J., Gann, J., Cooper, D., Eisner, L., Duffy-Anderson, J., Sheffield, G., Pickart, R., Mounsey, A., Willis, M. L., Stabeno, P., & Siddon, E. Paralytic shellfish toxins in Alaskan Arctic food webs during the anomalously warm ocean conditions of 2019 and estimated toxin doses to Pacific walruses and bowhead whales. Harmful Algae, 114, (2022): 102205, https://doi.org/10.1016/j.hal.2022.102205.
Description:
Climate change-related ocean warming and 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). This study reports Paralytic Shellfish Toxin (PST) concentrations quantified in Arctic food web samples that include phytoplankton, zooplankton, benthic clams, benthic worms, and pelagic fish collected throughout summer 2019 during anomalously warm ocean conditions. PSTs (saxitoxin equivalents, STX eq.) were detected in all trophic levels with concentrations above the seafood safety regulatory limit (80 μg STX eq. 100 g−1) in benthic clams collected offshore on the continental shelf in the Beaufort, Chukchi, and Bering Seas. Most notably, toxic benthic clams (Macoma calcarea) were found north of Saint Lawrence Island where Pacific walruses (Odobenus rosmarus) are known to forage for a variety of benthic species, including Macoma. Additionally, fecal samples collected from 13 walruses harvested for subsistence purposes near Saint Lawrence Island during March to May 2019, all contained detectable levels of STX, with fecal samples from two animals (78 and 72 μg STX eq. 100 g−1) near the seafood safety regulatory limit. In contrast, 64% of fecal samples from zooplankton-feeding bowhead whales (n = 9) harvested between March and September 2019 in coastal waters of the Beaufort Sea near Utqiaġvik (formerly Barrow) and Kaktovik were toxin-positive, and those levels were significantly lower than in walruses (max bowhead 8.5 μg STX eq. 100 g−1). This was consistent with the lower concentrations of PSTs found in regional zooplankton prey. Maximum ecologically-relevant daily toxin doses to walruses feeding on clams and bowhead whales feeding on zooplankton were estimated to be 21.5 and 0.7 μg STX eq. kg body weight−1 day−1, respectively, suggesting that walruses had higher PST exposures than bowhead whales. Average and maximum STX doses in walruses were in the range reported previously to cause illness and/or death in humans and humpback whales, while bowhead whale doses were well below those levels. These findings raise concerns regarding potential increases in PST/STX exposure risks and health impacts to Arctic marine mammals as ocean warming and sea ice reduction continue.
Description:
This research was funded by ECOHAB project number NA20NOS4780195 (to KAL and DMA), the North Pacific Research Board (NPRB Arctic Integrated Ecosystem Research Program), the Bureau of Ocean and Energy Management (BOEM), the National Science Foundation (NSF) Office of Polar Programs (OPP-1823002 and OPP-1733564), the National Oceanic and Atmospheric Administration (NOAA) Arctic Research program (through the Cooperative Institute for the North Atlantic Region [CINAR; Grants NA14OAR4320158 and NA19OAR4320074] and the Cooperative Institute for the North Atlantic Region NOAA CINAR Grant # 22309.07 UMCES [to JG at the University of Maryland Center for Environmental Science]), the Alaska Sustainable Salmon Fund project #51002, the Alaska Department of Fish and Game, the North Slope Borough Department of Wildlife management, the U.S. National Park Service Shared Beringian Heritage Program grant # P21AC12214-00, and NOAA's Northwest Fisheries Science Center (NWFSC) and Alaska Fisheries Science Center (AFSC). We also thank the RACE Groundfish and Shellfish Assessment Programs of the NOAA Fisheries AFSC and the crew of the F/V Knight for their assistance in securing additional benthic biological samples used in this study. Collection of harvested bowhead whale samples was conducted under NMFS Permit #21386. Collection of harvested walrus samples was conducted under US Fish and Wildlife permit #MA-041309-5. This is ECOHAB publication #1000.
Keywords:
harmful algal blooms
;
algal toxins
;
trophic transfer
;
saxitoxin
;
paralytic shellfish poisoning
;
marine mammals
Repository Name:
Woods Hole Open Access Server
Type:
Article
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