Dynamics of a super-population of dolly varden in the Chiniak Bay system, Kodiak Island, Alaska

Abstract

A weir was operated at Buskin Lake, Kodiak Island, Alaska in the spring of 1990, 1991 and 1992 to study the stock structure of a super­population of Dolly Varden (Salvelinus malma) in Chiniak Bay. In 1991, Jolly-Seber estimates of abundance (60,585) and survival (29.3%) were higher than the weir estimates of 30,725 and 6.3%. Growth parameter estimates were 0.23 for the Brody coefficient and 522 mm as the largest fish in the population. Age 4-7 fish dominated the spring emigration from Buskin Lake. Dolly Varden found in the fall at the American and Olds rivers and Buskin Lake constitute the main spawning stocks for the Chiniak Bay super-population at 3,375, 2,669 and 3,711 fish respectively in 1991. A dynamic pool model used in conjunction with Relative Stock Density was effective in detecting increases in length-specific exploitation of larger fish, but not for detecting increasing fishing mortality in the mature stock.