Spawning run characteristics of Dolly Varden in the Kugururok River, Noatak Drainage, Alaska

Abstract

Biological information was collected on fall and summer spawning runs of Dolly Varden in the Kugururok River, in northwest Alaska. Partial weirs, angling, and beach seining were used to capture fish in 1993; angling was used in 1994. Run timing of both spawning groups was similar to other northern Dolly Varden populations. Males of both summer and fall spawners had higher mean lengths and greater length ranges than females. Lengths of migrating summer spawners in 1994 were larger than those in 1993. Weight-length relationships among the groups for both years were equal. Condition factors of spawners were lower than migrants; migrating fall spawners had the highest condition. The proportion of female summer spawners (82%) on the spawning grounds in 1993 was unusually high. Recommendations are to continue to monitor harvests and escapements and maintain at historic levels, determine implications of skewed sex ratios on spawning success, and genetically identify stocks.