Gulf of Alaska | Mammals DOCTORATE ORAL PRESENTATION DNA metabarcoding reveals extensive marine resource utilization by coastal gray wolves in Katmai National Park & Preserve Presenter: Ellen Dymit , ellen.dymit@oregonstate.edu, Oregon State University Kelsey Griffin , kelsey_griffin@nps.gov, Katmai National Park & Preserve Gretchen Roffler , gretchen.roffler@alaska.gov, Alaska Department of Fish & Game Taal Levi , taal.levi@oregonstate.edu, Oregon State University Gray wolves ( Canis lupus ) throughout most of their range are assumed to be obligate ungulate predators, but wolf populations with access to resource subsidies from the marine system may demonstrate incredible dietary flexibility. Wolves are seen frequently on the 500-mile coastline of Katmai National Park & Preserve in Southwest Alaska, but their role as generalist carnivores in the nearshore system is not well understood. On the Katmai coast, moose ( Alces alces ) occur at low density while sea otters ( Enhydra lutris ), Pacific salmon ( Oncorhynchus spp. ), and other marine species are abundant. We hypothesize that these unique circumstances of prey availability drive coastal wolves to hunt and forage extensively in the marine system, exploiting seasonal salmon availability, vulnerable marine mammals, and intertidal forage items. Katmai coastal wolves have been observed catching salmon alongside bears, carrying sea otter carcasses at offshore haul-outs, and in one instance killing an adult harbor seal ( Phoca vitulina ) in an intertidal area. In 2019 we began using noninvasive genetic sampling techniques and automatic digital cameras to study wolf foraging ecology on the Katmai coast. The main objectives of this diet study were to reconstruct coastal wolf diet via fecal DNA metabarcoding and document wolves foraging and hunting in the marine system on trail cameras. In the summers of 2021 and 2022 (June through September) we deployed trail cameras and collected approximately 900 wolf scat samples from seven distinct sites along Katmai’s coastline. Initial DNA metabarcoding results from a subset of these samples (n = 424) reveal a diversity of marine prey items consumed by Katmai coastal wolves, including sea otters, harbor seals, Steller sea lions, flounder, salmon, rock gunnels, halibut, whales, razor clams, blue mussels, crabs, and feather duster worms. Sea otters and salmon are particularly common in coastal wolf diets, appearing in approximately 1/3 and 1/4 of coastal wolf scats, respectively. Sea otters were the most abundant prey item overall and were consumed by wolves at all sites. Our findings demonstrate the importance of cross-boundary resource subsidies in an Alaskan intertidal system and highlight a novel food web linkage between a terrestrial (wolf) and marine (sea otter) apex predator.
Alaska Marine Science Symposium 2023 34
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