Variation in quillback rockfish (<I>Sebastes maliger</I>) growth patterns from oceanic to inland waters of the Salish Sea

Abstract

Identifying and quantifying spatial patterns in demographics and life-history characteristics is important for the management of temperate marine fishes. Quillback rockfish, Sebastes maliger (Jordan and Gilbert, 1880), is a long-lived scorpaeniform inhabiting the oceanographically complex marine and inland coastal waters of Washington and british columbia, collectively known as the salish sea. We compared patterns of growth variation in quillback rockfish from four regions across the salish sea, representing oceanographically distinct inland marine water bodies. We fit the von bertalanffy growth model to length-at-age data from Juan de Fuca strait, strait of Georgia, Admiralty Inlet, and Puget sound, and tested for differences in growth parameter estimates. The largest asymptotic size occurred in quillback rockfish nearest to oceanic waters (Juan de Fuca strait) followed by significantly smaller asymptotic sizes moving inland. Inland rockfish also reached their asymptotic size at an earlier age than oceanic individuals, suggesting a gradient of growth types from oceanic to inland marine waters. The growth patterns in quillback rockfish reported here may have been mediated by any or all of a number of environmental (or other) conditions that varied widely across the four regions studied, including water properties (temperature and salinity), habitat quality, fishery exploitation, and pollution.