The effect of food composition on Pacific oyster Crassostrea gigas (Thunberg) growth in Korea: a modeling study

Abstract

A population dynamics model, originally derived for the Eastern oyster Crassostrea virginica and later modified for the Pacific oyster C. gigas in Japan, is applied to investigate the effect of food composition on the growth rate of C. gigas, which is in aquaculture in Kamakman Bay, Korea. Annual environmental cycles of temperature, salinity and particle concentration as well as various measures of food are used in the model. The model reproduces the general features of observed oyster growth in the different regions of the bay. Simulations show that chlorophyll- a is an inadequate measure of food for oysters. Using labile lipid+protein+carbohydrate as a food source results in higher growth rates than observed, suggesting that a surplus of potential food is available in the water column, but that much of it is not utilized by oysters and that little of it is present as chlorophyll containing cells. Assuming that most of the food is available as small particles, which are filtered at low retention efficiency by oysters, results in simulated growth rates that are similar to observed field growth rates. The oyster model used in this research is shown to be generally applicable to the Pacific oyster, C. gigas.