Seasonal growth, organ indices and food consumption of the Japanese scallop <i>Patinopecten</i> <i>yessoensis</i> (Jay, 1857) in relation to food availability in Tokoro seabed, Okhotsk Sea, North Japan

The coastal waters off Tokoro, Okhotsk Sea have been characterized by a substantial decrease in primary production from spring to summer season which will repercussions on the maintenance of Japanese scallop Patinopecten yessoensis (Jay, 1857) culture. This study examined seasonal changes growth, condition and organ indices relation environmental conditions, compared sinking particulate organic carbon (POC) flux as an estimate food availability requirements. Monthly specimens were obtained July 2005, May 2006 December 2008 Sea. Growth parameters derived modified von Bertalanffy growth function 885 individuals mean asymptotic shell height H∞=126.51 mm, Brody coefficient K=0.081 year−1, t0=6.19 year. Condition (CI) gonadosomatic (GSI) increased April May, decreased June September, but again October until May. adductor muscle index (AMI) October, declined November when CI GSI began increase. Primary (PP) chlorophyll biomass (25.75–29.74 µg C L−1 h−1 1.74–5.37 L−1) autumn (0.90–10.83 0.29–0.75 concurrent with decreasing GSI, no deleterious effect AMI was evident during these periods. POC (25–68 mg m−2 day−1) low gonad activity also low, started increase peak. Although deficit (lower fluxes than consumption) observed summer, potential advection matter offshore nearshore region may provided additional source bottom-cultured scallops, contributing part somatic tissues.