A model for planning culturing sites based on responsible farming concept of nitrogen-phosphorus balance

By studying nitrogen and phosphate nutrients, we proposed a model for planning composite fish-algae culturing sites based on a responsible farming concept. The model only considers artificial breeding activities, regarding feed as the only nutrient input while fish and algae as nutrient output, but not regarding of the absorption and transfer caused by exchange of sea water, nutrient absorption by natural algae, uneaten food ingested by natural animals, feces biodegradation, etc.. The result demonstrates that responsible farming can be realized by composite fish-algae culture. However, the ratio of farming scales shows great disparity between fish and algae. The ratio of algae (Sargassum fusiforme) and fish (Pseudosciaena crocea) is 95:1, and their biomass ratio is 30:1. It is recommended to combine shellfish farming with algae to increase nutrient transfer.