Spawning Distribution of Bering Ciscoes in the Yukon River

Abstract

AbstractBering CiscoesCoregonus laurettaeare anadromous salmonids with known spawning populations only in the Yukon, Kuskokwim, and Susitna rivers in Alaska. A commercial fishery for the species was recently initiated at the mouth of the Yukon River, inspiring a series of research projects to enhance our understanding of the exploited population. This study was designed to delineate the geographic spawning distribution of Bering Ciscoes in the Yukon River. One hundred radio transmitters per year in 2012 and 2013 were deployed in prespawning Bering Ciscoes at a site located 1,176 km upstream from the sea. A total of 160 fish survived fish wheel capture and tagging, avoided harvest and predation after tagging, and continued migrating upstream to their spawning destinations. Approximately 79% migrated to spawn in the upper Yukon Flats, upstream from the mouth of the Porcupine River, and 21% migrated to spawn in the lower Yukon Flats. Locating the Bering Cisco spawning area, which is almost entirely encompassed by the Yukon Flats National Wildlife Refuge, enhances our ability to protect it from anthropogenic disturbance and enables future biological research on the spawning population.Received July 25, 2014; accepted November 13, 2014