Fisheries Farming Laboratory, Fisheries Experimental Station, Wakayama Research Center of Agriculture, Forestry and Fisheries, Tanabe, Wakayama 646- 0058, Japan
This study is compared the sediment quality of fish farming areas with those of non fish farming ones, to clarify the environmental characteristics of the sediment in fish farming areas. For chemical oxygen demand, total organic carbon, total nitrogen and C/N, no difference was observed between fish farming areas and non fish farming areas. In contrast, total phosphorus concentrations in fish farming areas were higher than those of non fish farming areas. C/P and N/P were lower than those of non fish farming areas. These results caused by the accumulation of Ca-bound phosphorus to the sediment. Concentrations of Ca-bound phosphorus, which originates from fish feed and feces, reached more than 1 mg g-1 in the sediment of fish farming areas. These findings reveal that determination of phosphorus compounds in the sediment enables us to show the area affected by the organic loads of fish farming.