Swift’s Scallop (Chlamys swiftii, Bivalvia) Resources and the Structure of Beds in Coastal Waters of Primorsky Krai, Sea of Japan

Abstract

The current status of Chlamys swiftii beds and resources of this species in the coastal waters of Primorsky krai, Sea of Japan, are assessed on the basis of data collected in 2007–2021. It has been found that scallops do not form dense aggregations sufficient for commercial harvesting. Scallop beds with the highest average biomass (22.5 ± 5.0 g/m²) are concentrated in the waters from Cape Povorotny to Cape Yuzhny; beds with the lowest biomass are in Peter the Great Bay (3.7 ± 2.1 g/m²). All beds have a mosaic pattern of distribution. The total stock of this scallop species is estimated at 1400 t; the commercial stock, at 1300 t. About 99% of the total stock in the coastal waters of Primorsky krai is concentrated in the area from Cape Povorotny to Cape Zolotoy. In these waters, the recruitment of juveniles to the stock has been found to be more regular and active than in Peter the Great Bay. The percentage of scallops of noncommercial size varies from 1.9 to 19.0%. The Ch. swiftii beds in Peter the Great Bay are dominated by individuals at age of 3–6 years with a shell height of 80–115 mm; in the area from Cape Povorotny to Cape Zolotoy, by individuals at ages of 3–7 years with a shell height of 70–110 mm. The modal age of scallops is 4 years, and the maximum age ranges from 7 to 12 years.