Arctic grayling investigations in the Tok River drainage during 1993

Description

This study was partially undertaken because knowledge of Arctic grayling Thymallus arcticus in the Tok River drainage of eastern interior Alaska was deficient in providing direction for the management of the drainage's seasonal Arctic grayling fisheries. Impetus behind the study was recent public concern that the Arctic grayling fishery in the Tok Overflow, a tributary of the Tok River, had severely deteriorated. The study objectives were to estimate the age and size composition of Arctic grayling in the Tok Overflow. These objectives were not met due to the scarcity of fish; however, Arctic grayling were sampled in four other locations in the drainage: the Tok River, Little Tok River, Tok Overflow #2, and Mineral Lake Outlet. The Tok River below the Tok Overflow was found to be an overwintering area for Arctic grayling that disperse upstream at least to Mineral Lake Outlet. Water temperatures indicated the Tok Overflow to be the coldest stream in the study area and likely inhospitable as a summer feeding area for Arctic grayling. Age and size compositions of adult Arctic grayling spawning in Mineral Lake Outlet are presented and compared to similar samples collected in 1988 and 1990. Males were significantly larger than those sampled in prior studies possibly due to four years of restrictive sport fishery regulations. The study provided needed insight of the Arctic grayling resource and habitat in the Tok River drainage and afforded a starting point in addressing public concerns and formulating objectives for future research investigations.

Subjects

Genres

• Statistics

Series Statement

• Fishery data series -- no. 94-19.

Links

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