Benthic habitat health assessment using macrofauna communities of a sub-tropical semi-enclosed bay under excess nutrients

This research was conducted to assess the ecosystem health of Daya Bay benthic habitat, investigate the effects of anthropogenic nutrients, and evaluate the application of ecological indicators for benthic health assessment. Environmental indicators and macrobenthic communities, were investigated during summer and winter 2015. Results indicated a strong seasonality in biotope of intertidal and subtidal zones. Lower macrobenthic diversity were calculated from subtidal inner bay, reflecting the effects of anthropogenic nutrients. However, intertidal sites in that part were indicated to be in a relatively healthier ecological status. Seasonal effects of excess nutrients on benthic habitat were reflected in ecological indicators. It is concluded that the excess nutrients at spatiotemporal scales, influences on the health of benthic habitat. Eventually, it is recommended by this research that, with considering the natural/anthropogenic circumstances, the taxonomic and phylogenetic ecological indicators would be helpful tools to evaluate the benthic health of a typical sub-tropical semi-enclosed bay. - Highlights: • Strong seasonality of environmental variables was observed in Daya Bay. • Obvious impacts caused by excess nutrients (mostly mariculture) and nuclear power plants were indicated. • Subtidal and intertidal sites adjacent to the pollution sources displayed worse ecological status than the other parts. • Multiple sets of ecological indicators would be helpful to make a more precise benthic health assessment of a semi-enclosed bay.