An experimental study on nitrogen, phosphorus and carbon budgets in intensive pond of shrimp Fenneropenaeus chinensis

Chemical budgets can be formulated to account for all sources of nutrient gains and losses in aquicolous ecosystem. Therefore, nutrient budget was used in this study to assess the material circulation in shrimp pond ecosystem. The results showed that the ratio of nutrient utilized by shrimp production ranked as follows: N (27.40%), P (20.69%) and C (17.32%); as for the nutrient losses, most phosphoruswas sediment to the pond bottom, occupying 52.04% in gross P losses; maximum nitrogen suspended or dissolved in water, occupying 61.06% in gross N losses; carbon was consumed mostly by pond respiration, occupying 40.86% in gross C losses. Thus, in closed pond ecosystem, shrimp production had so inefficient utilization to nutrition that N and P accumulated or subsided in shrimp pond, except that C released mostly by pond respiration.