Seasonal movements of northern pike in Minto Flats, Alaska

Abstract

Northern pike (Esox lucius) is a large, long-lived piscivorous species that are harvested in sport and subsistence fisheries in Alaska. My study described the seasonal movements of northern pike that inhabit the Minto Lakes portion (Goldstream Creek drainage) of the Minto Flats wetland complex, Alaska, from May 2008 through January 2010. Very high frequency (VHF) radio tags (n = 220) were surgically implanted in northern pike in Minto Flats in May 2007, 2008, and 2009, and fish were relocated with fixed telemetry stations and aerial- and boat-based telemetry surveys. Radio-tagged northern pike displayed a distinct spring pre-spawning migration into the Minto Lakes study area, where they remained for the duration of the open-water season. A protracted out-migration occurred between late September and early December, with downstream movements peaking in November and October of 2008 and 2009, respectively. Radio-tagged fish present in the Minto Lakes study area during the open-water season overwintered exclusively in a 26-km reach of the Chatanika River from its confluence with Goldstream Creek upstream to the Murphy Dome Road access point. Daily movement rates were greatest during May and August. In addition to providing a better understanding of northern pike life history in Minto Flats, these results will aid managers and researchers by identifying critical habitats and providing information to better design future population assessment experiments.