Relationships between chemical characteristics of the sediment and dominant species of macrobenthos communities in spring in aquaculture farm along the coast of Wakayama Prefecture, Japan

Relationships between chemical characteristics of the sediment and macrobenthos communities in spring were examined to establish a method for evaluating the environment of aquaculture farms, and the results were compared with summer data previously reported. Proper standard values for the environment of aquaculture farms are proposed. Dominant appearances of three species (Scoletoma longifolia, Capitella sp., Theora lubrica) in spring virtually fit the standard values (6.2, l0.3, 16.4 mg/g) of total organic carbon (TOC), suggesting the possibility of evaluating the environment of aquaculture farms. Furthermore, the evaluation of TOC in sediment and the biomass of S. longifolia in spring, together with acid volatile sulfide (AVS) of the sediment in summer, is a valid method of comprehending the environmental conditions of aquaculture farms. Hence, as a regular survey by aquaculturist, measuring AVS of the sediment in summer could be sufficient. But in case of those aquaculture farms designated as critical areas in terms of standard values of AVS in summer, a detailed survey should be conducted to measure TOC in the sediment and the biomass of S. longifolia in spring. This would make it possible to precisely evaluate the environmental conditions of aquaculture farms.