SUMMER DISTRIBUTION OF EARLY-LIFE STAGES OF WALLEYE POLLOCK, THERAGRA-CHALCOGRAMMA, AND ASSOCIATED SPECIES IN THE WESTERN GULF OF ALASKA

A midwater trawl survey was conducted during July 1991, to examine the large-scale distribution patterns of late larval and early juvenile w alleye pollock, Theragra chalcogramma, and associated fish taxa in the western Gulf of Alaska. Gear comparisons between the anchovy and Meth ot trawls were conducted to evaluate which was the more efficient samp ler for the size range of T. chalcogramma present during this time of the year. Both gears showed similar densities through the dominant siz e class of fish caught, but the Methot trawl caught significantly more T. chalcogramma in the smallest (mostly larval) size ranges available . Accordingly, a grid of stations was occupied in which only the Metho t trawl was used. Although 53 fish taxa were collected overall in the 61 Methot trawls, the majority (84%) of the larval catch consisted of only five taxa: flathead sole, Hippoglossoides elassodon; walleye poll ock, T. chalcogramma; arrowtooth flounder, Atheresthes stomias; Pacifi c cod, Gadus macrocephalus; and unidentified sculpins, Icelinus spp. T heragra chalcogramma and G. macrocephalus were the dominant (>99%) juv eniles collected in the survey. The highest catches of larval (13-25 m m SL) and juvenile (26-52 mm SL) T. chalcogramma were found inshore al ong the Alaska Peninsula and near offshore island groups. Recurrent Gr oup Analysis and Two-way Indicator Species Analysis both showed that T . chalcogramma tended to be frequently associated with a large heterog eneous grouping of taxa, including G. macrocephalus, several pleuronec tids, and other winter-spring spawning species. The rankings of the do minant taxa in the Methot trawl survey exhibited a greater coherence t o the rankings of adult fishes from bottom trawl surveys in the previo us year than did those of an ichthyoplankton survey that used bongo ne ts a few months earlier than the Methot trawl survey.