Decadal Trends in Age Structure and Recruitment Patterns of Ocean Quahogs Arctica islandica from the Mid-atlantic Bight in Relation to Water Temperature

Abstract

Abstract Ocean quahogs (Arctica Islandica) are long-lived bivalves. Distribution patterns and biology of ocean quahogs in the Mid-Atlantic Bight (MAB) off the east coast of North America are directly related to bottom water temperatures. We examined long term recruitment patterns for ocean quahogs across temporal (decadal) and spatial (latitudinal, bathymetric) scales using a spatially defined (Long Island Sound to Chesapeake Bay mouth) population encompassing a broad size (age) range of animals that had not yet recruited to the commercial fishery [<80 mm shell length (SL)]. An age-at-length relationship for quahogs less than 80 mm SL is described using a power function. Quahog age did not vary significantly with depth or region, nor were any interaction terms between age and length with depth or region significant. An age-length key was developed for ocean quahogs to generate age frequencies for each station. Principal components analysis (PCA) on the resulting age-frequency distributions standardized pe...