Kenai Peninsula Invasive Fish Investigations, Eradication, and Native Fish Restoration, 2017-2020

In 2017, the Alaska Department of Fish and Game (ADF&G) conducted gillnet and eDNA sampling surveys on the Kenai Peninsula to define the distribution of invasive northern pike. These surveys discovered invasive northern pike (Esox lucius) and muskellunge (Esox masquinongy) in several waters, two of them near waters collectively known as the Tote Road Lakes (TRL) south of Soldotna, Alaska, previously known to contain northern pike. During October 2018, ADF&G applied the piscicide rotenone to the TRL to eradicate invasive fish. The success of the eradication effort was evaluated by caged sentinel fish responses, posttreatment monitoring of rotenone concentration and persistence, and gillnetting surveys. Collectively, the evaluation results suggest all invasive fish were removed. Beginning in 2019, wild juvenile rainbow trout (Oncorhynchus mykiss) and coho salmon (O. kisutch) were collected from Kenai River tributaries and relocated to the TRL to establish a new sport fishery. Researchers, representing numerous academic universities in coordination with ADF&G, released threespine stickleback (Gasterosteus aculeatus) into the TRL to restore the lone fish species known to naturally occur there. The total number of wild fish released into the TRL between 2019 and 2020 was 8,740 threespine stickleback, 3,876 juvenile rainbow trout, and 15,378 juvenile coho salmon. The rainbow trout and coho salmon used for release into the TRL were wild stocks from the Kenai River drainage. Such releases of rainbow trout and coho salmon into the TRL are planned to continue through at least 2023 to provide an alternate fishery to replace the fishery for invasive fish.