Study On The Carrying Capacity In Sanpan Bay Of Dongtou Islands, Zhejiang Province

The carrying capacity is an interlaced field of multidisciplinary, andreflects certain characteristics of the ecosystem. As a quantitative indicator forthe macroeconomic regulation of aquaculture, the carrying capacity can providescientific information for the government to develop aquaculture policies.In this study, we used a diffusion simulation model to estimate the carryingcapacity of Sanpan Bay using inorganic nitrogen as a pollution control factor.We also investigated the hydrodynamic characteristics, environmental qualitystatus and biological loading capacity of breeding fish in Sanpan Bay ofDongtou Islands, Zhejiang Province. Results showed that the water exchangecapability was so powerful that the water in Sanpang Bay could be exchangedby seawater from the exterior bay in a tidal period. However, eutrophication inthis area was serious. The increment of inorganic nitrogen in this area from cageculture was about82%. The inorganic nitrogen from cage culture mainly camefrom remaining bait, stool, and ammonia excretion. The inorganic nitrogendeteriorated the sediment and water quality and therefore posed a risk on theaquaculture in this area. On the basis of the present layout of the aquaculture inthis area and to meet the standards that the increment of inorganic nitrogen incage culture areas should be less than0.049mg/L and the inorganic nitrogenconcentration in the culture areas should not exceed0.400mg/L, the carryingcapacity in Sanpan Bay was estimated to be about2100. However, the carryingcapacity could be increased to about6200if using artificial synthetic food.