Stock Definition of Silver Hake in the New England-Middle Atlantic Area

Abstract

The stock structure of silver hake Merluccius bilinearis in the New England-middle Atlantic area was examined with bottom trawl, commercial fishery, and morphometric data. Seasonal catches indicated a discontinuous distribution of this species; the shoal portion of Georges Bank separated individuals inhabiting the waters north and south of the bank, providing qualitative evidence for the existence of two stocks of silver hake off the northeastern coast of the United States. Linear discriminant function analyses indicated that silver hake comprise two stocks, although some intermixture may occur on Georges Bank. Analyses performed on individual fish in spawning and postspawning condition indicated greater group separation during the spawning season than at other times throughout the year. Proposed stock groupings include a northern stock made up of silver hake found on northern Georges Bank and in the Gulf of Maine, and a southern stock comprising fish from the waters of southern Georges Bank south to Cape Hatteras, North Carolina.