Koel, Todd M.Tronstad, Lusha M.Arnold, Jeffrey L.Gunther, Kerry A.Smith, Douglas W.Syslo, John M.White, Patrick J.2019-06-122019-06-122019-03Koel, Todd M. , Lusha M. Tronstad, Jeffrey L. Arnold, Kerry A. Gunther, Douglas W. Smith, John M. Syslo, and Patrick J. White. "Predatory fish invasion induces within and across ecosystem effects in Yellowstone National Park." Science Advances 5, no. 3 (March 2019). DOI:10.1126/sciadv.aav1139.2375-2548https://scholarworks.montana.edu/handle/1/15495Predatory fish introduction can cause cascading changes within recipient freshwater ecosystems. Linkages to avian and terrestrial food webs may occur, but effects are thought to attenuate across ecosystem boundaries. Using data spanning more than four decades (1972-2017), we demonstrate that lake trout invasion of Yellowstone Lake added a novel, piscivorous trophic level resulting in a precipitous decline of prey fish, including Yellowstone cutthroat trout. Plankton assemblages within the lake were altered, and nutrient transport to tributary streams was reduced. Effects across the aquatic-terrestrial ecosystem boundary remained strong (log response ratio <= 1.07) as grizzly bears and black bears necessarily sought alternative foods. Nest density and success of ospreys greatly declined. Bald eagles shifted their diet to compensate for the cutthroat trout loss. These interactions across multiple trophic levels both within and outside of the invaded lake highlight the potential substantial influence of an introduced predatory fish on otherwise pristine ecosystems.CC BY: This license lets you distribute, remix, tweak, and build upon this work, even commercially, as long as you credit the original creator for this work. This is the most accommodating of licenses offered. Recommended for maximum dissemination and use of licensed materials.https://creativecommons.org/licenses/by/4.0/legalcodeArticle