Pacific salmon are fantastic (and tasty) animals. They are born in freshwater, migrate to sea, and return to their natal stream where they spawn and die. They provide an enormous pulse of marine derived nutrients to terrestrial systems. Predators, and particularly bears, rely heavily on salmon. Humans also rely on salmon for livelihoods and food. My research evaluates salmon management goals and their impact on wildlife by quantifying the level of competition between salmon fisheries and wildlife users of salmon. Fishery certifiers such as the Marine Stewardship Council state that fisheries must have acceptable impacts on the ecosystem, but quantitative methods to determine whether these goals are being met are still lacking. I am working to develop these goals for Pacific salmon fisheries.
In addition to quantitative research, our fieldwork near Haines, Alaska quantifies the importance of salmon carcasses to terrestrial wildlife, and the ecosystem effects of abundant salmon-supported bears. (Original artwork by Yiwei Wang)
Relevant Publications
Levi. T., Allen, J. M., Bell, D., Joyce, J. Russel, J. R., Tallmon, D. A., Vulstek, S. C., Yahan, Y., Yu, D. W. 2019. Environmental DNA for the enumeration and management of Pacific salmon. Molecular Ecology Resources
Shakeri, Y., White, K.W., Levi, T. 2018. Seed dispersal and resource subsidies from salmon-supported bears to granivores. Ecosphere
Harrer, L.E.F., Levi, T. 2018. The primacy of bears as seed dispersers in salmon-bearing ecosystems. Ecosphere
Adams, M.S., Service, C., Bateman, A., Bourbonnais, M., Artelle, K., Nelson, T., Paquet, P., Levi, T., Darimont, C.T. 2017. Intrapopulation isotopic niche diversity over landscapes; spatial patterns inform conservation of bear-salmon systems. Ecosphere
Wheat, R.E., Lewis, S.B., Wang, Y., Levi, T., Wilmers, C.C. 2017. Intraspecific variation in movement strategies among bald eagles (Haliaeetus leucocephalus) in an anadromous fish system.Movement Ecology
Wheat, R.E., Allen, J.M., Miller, S.D.L, Wilmers, C.C., Levi, T. 2016. Environmental DNA from residual saliva for efficient noninvasive genetic monitoring of brown bears (Ursus arctos). PLoS ONE
Levi, T., Wheat, R., Allen, J.M., Wilmers, C.C. 2015. Differential use of salmon by vertebrate consumers: implications for conservation. PeerJ. 3:E1157
Levi, T., Darimont, C.T., MacDuffee, M., Mangel, M., Paquet, P., Wilmers, C.C. 2012. Using Grizzly bears to assess harvest-ecosystem tradeoffs in salmon fisheries. PLoS Biology. 10(4)