Study On Carrying Capacity Of Cultured Tidal Shellfish In Rushan Bay

Tidal flat is the ecosystem which is affected alternately by ocean and land, and the exploitation of tidal flat has given great impetus for the development of economy and society in China. Some inappropriate ways of aquaculture, however, have resulted in the worseness of environment, which would restrict and endanger the development of aquaculture. The study of carrying capacity may resolve the problem of ecosystem by overstocking, so the study on carrying capacity of cultured tidal shellfish is very necessary.For a valid evaluation for carrying capacity of an ecosystem for shellfish growth and production, it is necessary to include processes relating to the ingestion rate of the shellfish, and processes involved with the supply of food to the shellfish populations. A dynamic model for carrying capacity of cultured tidal flat shellfish in Rushan Bay was established according to the principles of food balance and the main processes involved in evaluation for carrying capacity through historical data, field surveys, in situ simulated experiments and simulated natural condition experiments. In the model, 4 state variables (phytoplankton, zooplankton, shellfish, seston) were included. The results showed that this model could simulate the seasonal variations of phytoplankton biomass properly. Not only the logical structure but model parameters were feasible. Then the model was uses to estimate carrying capacity of cultured tidal flat shellfish in Rushan Bay of different culture seasons. The main conclusions are as follows:1. Chlorophyll a concentrations of phytoplankton in the East Valley of Rushan Bay are pronounced spatial and seasonal variations. The highest average chlorophyll a concentration occurred in August and the lowest in October. Primary production in the East Valley of Rushan Bay is pronounced spatial and seasonal variations, too. The highest average primary production occurred in October and the lowest in June. The industry of aquaculture has great influence to the phytoplankton biomass and primary...