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COSEWIC Assessment and Update Status Report on the Bering Cisco in Canada


Habitat Requirements

The current knowledge of the distribution of Bering cisco suggests the species has an origin in Beringia (McPhail and Lindsey 1970). The Bering cisco is a common fish in Alaskan coastal habitats. It is believed to display a life history and habitat requirement similar to those of the Arctic cisco (see Scott and Crossman 1973) that inhabit the Mackenzie Delta region of Canada. The species is anadromous, leaving the sea or estuarine waters in spring and summer, ascending freshwater rivers to spawn, and then

returning to the sea following spawning. Spawning runs have been reported in the Yukon River mainstem in Alaska, and possibly upstream in some of the larger tributaries (Alt 1973; Brown, pers. comm., 2003). Bering cisco apparently spend more time in saline waters than other known anadromous populations of coregonines. While detailed spawning descriptions have not been reported, field observations imply the use of gravel beds in swiftly flowing water (Brown, pers. comm., 2003). The Bering cisco apparently does not feed during spawning migrations (Morrow 1980; Brown, pers. comm., 2003). Microchemical analyses of otoliths indicates that the species reach marine water early in life, where they feed and rear in brackish coastal waters until sexual maturity (Brown, pers. comm., 2003).




Since the Yukon River flows through or borders five national wildlife refuges in Alaska, a significant portion of the migratory route is encompassed under some level of protection. The Yukon Flats National Wildlife Refuge, for example, encompasses one of the only known spawning areas on the Yukon River. Although there are no exclusive marine preserve designations along the Alaskan coast, there are several terrestrial wildlife refuges and preserves of varying size, offering some level of scrutiny to any potential alteration of aquatic habitat from onshore industrial development.