Abstract

This study was conducted to analyze the stock abundance and population dynamics of the bivalve Keenocardium buelowi inhabiting the coastal waters near Yokji Island, Tongyeong, and to propose appropriate management strategies. From May to December 2024, six dredge surveys were performed, and shell length, body weight, and age composition were analyzed using stock dynamic models. The instantaneous total mortality coefficient (Z), natural mortality coefficient (M), and fishing mortality coefficient (F) were estimated as 0.982, 0.724, and 0.258 per year, respectively, while the age at first capture (tc) was 3.28 years. The mean density was 4.89 individuals/m2 (192.3 g/m2 in unit biomass), and the total stock biomass was estimated to be approximately 323.1 tons. The application of the Beverton-Holt model suggested that maximum yield could be achieved by reducing tc to 2-2.5 years and increasing fishing mortality above 2.0; however, this approach could lead to overexploitation. For sustainable harvesting, maintaining tc above 3.0 years and fishing intensity at 1.5 was found to be optimal, yielding an acceptable biological catch (ABC) of 198.1 tons. Although the K. buelowi stock in the Yokji waters is currently under low fishing pressure, significant natural mortality occurs due to the collapse of the thermocline after summer. Therefore, systematic management-based on the Fisheries Resources Management Act and the Fisheries Act-is required, including the designation of the area as a fisheries management zone, to ensure adaptive management in the face of future climate change.