DEPTH AND SUBSTRATE AS DETERMINANTS OF DISTRIBUTION OF JUVENILE FLATHEAD SOLE (HIPPOGLOSSOIDES ELASSODON) AND ROCK SOLE (PLEURONECTES BILINEATUS), IN KACHEMAK BAY, ALASKA

Three transects in Kachemak Bay, Alaska, were sampled in September 199 4, May and August 1995, and February, May, and August 1996. Juvenile f lathead sole, Hippoglossoides elassodon, and rock sole, Pleuronectes b ilineatus, were the most abundant flatfishes, comprising 65-85% of all flatfishes captured at any period. Collections of fish and sediments were made at regular depth contour intervals of 10 m. Habitat distribu tion was described by depth at 10 m increments and sediment percent we ights of gravel, sand, and mud. Year-round habitat of flathead sole ag e-0 was primarily from 40 to 60 m, and age-1 habitat was primarily fro m 40 to 80 m. Summer habitat of rock sole age-0 and -1 was from 10 to 30 m, and in winter they moved offshore to depths of up to 150 m. Both age classes of flathead sole were most abundant on mixed mud sediment s, while age-1 were also in high abundance on muddy sand sediments. Ro ck sole age-0 and -1 were most abundant on sand, though age-1 were als o found on a variety of sediments both finer and coarser grained than sand. Flathead sole and rock sole had distinctive depth and sediment h abitats. When habitat overlap occurred between the species, it was mos t often due to rock sole moving offshore in the winter. Abundances wer e not significantly different among seasons for age-1 flatfishes. (C) 1998 Elsevier Science B.V. All rights reserved.