Estimation of Carrying Capacity of Manila Clam (Ruditapes philippinarum) in Jiaozhou Bay Based on Spatial and Temporal Distribution of Chlorophyll a

Abstract:

Based on Dame indices and Herman model, the carrying capacity of Manila clam (Ruditapes philippinarum) in Jiaozhou Bay is estimated with the comprehensive fishery survey data, field simulation experiment, and growth tracking data between July 2017 and April 2019. The results showed that the average chlorophyll a concentration was in the range of 2.09~4.28 mg/m3, with an average value of 3.07 mg/m3. The average clearance rate was 0.45 L/(h∙ind.) and converted to a unit-mass based value was 2.52 L/(g∙h). The average dry weight of Manila clams at 1, 2, and 3 ages were 0.18, 0.30, and 0.42 g, respectively. The water mass residence time was 52 days, the primary production time was 1.58 days, and the bivalve clearance time was 2.09 days in Jiaozhou Bay. The corresponding carrying capacity of Manila clam were estimated to be 637, 378, and 272 ind./m2 for 1-year, 2-year and 3-year old clams, respectively. Currently, the cultured quantity of Manila clams has exceeded the carrying capacity. It is recommended that the stocking density to be 582 ind./m2 if 2-year clams are considered as the target object, and the stocking density to be 789 ind./m2 if 3-year clams are considered as the target object. The results provide theoretical basis and necessary data for the development of the clam aquaculture in Jiaozhou Bay.