A

The project of cultivation of oyster has been designed to evaluate the growth rate, the mortality, the reproductive effort, production and biochemical composition of the oyster function of the density and the depth. This plan was intended:- to build model of growth rate,- to demonstrate the action of the different parameters on growth rate (temperature, food effect...),- to evaluate the density effect to see if the available food could be a limiting factor,- to estimate the effect of the depth joined to the impact of the high turbidity near the bot tom,- to detect the mortality related to the prevalence of diseases. The project began in July 1989 by dredging 20 000 small oysters at the mouth of the Patuxent River near Cove Point. Three experimental stations were selected in the Patuxent River to set up the structures, Benedict Bridge in the upper and the brackish water zone, Green Holly Pond at the mouth of the river and Chesapeake Biological Laboratory's Piero MATERIALS AND METHODS The data for biochemical composition were sampled from July 1989 until February 1990 at these three stations. Intervals for sampling were 15 days during the reproductive period and 30 days after october. The analysis have been achieved in the surface basket and on the bottom one, at only one density, the medium one (360 per m2). The design of the experiments was summarized in figure 1. A sample of 5 oysters for each sex had been analysed individually. The oysters which were returned to the laboratory were kept for 24 hours in ambiant filtered river water to empty their digestive tracts. The biome tric data collected on each oyster included length, total weight and fresh meat weight. The reproductive status was determined by examining a gonadal smear with a compound microscope. Meats were freeze-dried for 48 hours. The flesh was weighed and dried at 60°C for 72 hours, it was then pulverized in a mortar and analysed for its proximate biochemical components