SUMMER GROWTH-PATTERNS OF NORTHERN DOLLY-VARDEN (SALVELINUS-MALMA) SMOLTS FROM THE PRUDHOE BAY-REGION OF ALASKA

Summer length growth patterns of northern Dolly Varden (Salvelinus mal ma) smelts from the Sagavanirktok River, northern Alaska, were analyze d for the years 1985-1994 and found to be sigmoidal, indicating slow r ates of growth in early and late summer with the most rapid growth occ urring in midseason. Nonlinear logistic regression functions of mean c ohort length against date provided a reasonable fit of the data for al l years except for 1991, accounting for more than 94% (r(2) values ran ged from 0.95 to 0.99) of the variation in mean daily length in any gi ven year. Slow growth in early summer is in direct contrast with the g rowth patterns reported for juvenile broad whitefish (Coregonus nasus) and Arctic cisco (C. autumnalis) which inhabit the Sagavanirktok Rive r and estuary. Some possible explanations for the observed Dolly Varde n growth patterns include migration, dispersal, prey availability, wat er quality, and stock mixing.