Migratory Patterns of Different Spawning Aggregates of Dolly Varden in the Kenai River Watershed

摘要

Radiotelemetry was used to monitor the seasonal movements of adult Dolly Varden Salvelinus malma in the Kenai River watershed. Dolly Varden from spawning aggregates in Cooper Creek (N=20), Quartz Creek (N=60), South Fork of the Snow River (N=60) and the upper Kenai River (N=79) were implanted with radio transmitters and tracked for varying periods from September 1998 through December 2001. Nearly half (N=109) of the radio-tagged Dolly Varden provided movement information for one year or longer. All radio-tagged Dolly Varden migrated seasonally between lake and riverine habitats to fulfill critical habitat needs. Lacustrine habitats were selected for winter refuge with Kenai and Skilak lakes providing the majority of overwinter habitat. Movement to overwintering lakes began in October and was complete by December. Movement from overwintering lakes to summer feeding areas began in May. Patterns of movement during the summer months were different for each spawning aggregate, but were generally associated with the timing and location of smolting or spawning salmon. Most radio-tagged fish were found in riverine habitats from June through September except for fish from the Snow River spawning aggregate which remained in Kenai Lake through mid-summer. The Killey River was an important early summer feeding area for many fish, but by August most fish were found in the Kenai River above and below Skilak Lake. Fish were located at spawning areas from late September through October. Although a few fish spawned during consecutive years, it appears that most Dolly Varden from these spawning aggregates will skip a year or two between spawning.