Estimating the carrying capacity of a coastal bay for oyster culture: II. the carrying capacity of Geoje-Hansan Bay

摘要

A 3D hydrodynamic-ecological coupled model was applied to estimate carrying capacity in Geoje-Hansan Bay where is one of the most important oyster culturing grounds in Korea. We considered the carrying capacity as the difference between food supplyto the oysters and food demand, considering monthly difference of the actual growth. The food supply to the system was determined from the results of the model simulation (tidal exchange and chlorophyll a) over the culturing period from September to Mayof the following year. The food demand was estimated from the food concentration (chlorophyll a) multiple the filtration rate of oysters that is considered monthly different growth rate of oysters and food concentration. The values of carrying capacity for the system varied from 6.1 ton/ha (minimum carrying capacity) in February to 14.91 ton/ha (maximum carrying capacity) in April of marketable size oysters (>4 g wet-tissue weight) depending on temporal variations in the food supply. The oyster production calculated from present facilities was 9 ton/ha in wet-tissue weight in Geoje-Hansan Bay. This value corresponded to 60 percent of maximum carrying capacity of the system. The optimal carrying capacity without negatively affecting on oyster productionwas 5.5 ton/ha when calculated from annual statistic data and 6.1 ton/ha when determined by this study. These results suggest that it must be reduced 32 percent-39 percent of oyster facilities in the system.