Assessment of the ocean quahog, Arctica islandica (Linnaeus, 1767), in the New Jersey fishery

The status of the ocean quahog (Arctica islandica) resource off the New Jersey coast is described. Commercial landings and federal shellfish research survey data are analyzed to provide an update of the ocean quahog fishery in this area of the Mid-Atlantic region. Spatial and temporal trends in resource abundance, biomass, and size structure of the New Jersey ocean quahog fishery are compared to the data trends of other assessment regions along the East Coast. In addition, the population dynamics (i.e., reproduction, recruitment, growth, and mortality) of this species are examined to explain observations in the fishery. Ocean quahog populations off New Jersey consist of large (>70 mm in length), old (median age >70 years), and slow-growing individuals. Due to the absence of recruitment, very slow adult growth rates, low rates of adult mortality, and long time to maturity, there is little interannual variability in population size or structure. These unusual characteristics make the ocean quahog vulnerable to commercial exploitation. Hence, while New Jersey was the principal area of ocean quahog landings in the United States during the early 1990s (peak catch = 12,011 mt in 1990), concentrated fishing activity reduced the catch-per-unit effort substantially by 1992, and it now appears to have depleted the stock. As a result, the primary fishing grounds for ocean quahogs have recently shifted northward to less exploited areas.