Water-sediment regulation affects community structures of macrobenthic mollusks in the Yellow River estuary and adjacent waters

Abstract

The Yellow River Water-Sediment Regulation Scheme (WSRS), discharging large volumes of water and sediment through a channel in the Yellow River into the sea during summer, can profoundly impact the community structure in the Yellow River estuary and adjacent waters. For elucidating the effects of WSRS on the biodiversity and community compositions of epibenthic mollusks, in the present study, we investigated the species richness and abundance of epibiotic macrobenthic mollusks during the period of WSRS. A dramatic decrease in the abundance of mollusks during WSRS was observed, and the mollusk community showed a spatial structure with significant variation in species composition and diversity across sites. Bottom water temperature (TE), dissolved oxygen levels (DO), chlorophyll-a concentration (CA), and suspended solids (SS) were found to be significantly correlated with community structures. Salinity (SA) and clay (NS) content exhibited positive and negative correlations, respectively, with biodiversity. These results shed light on the impact of human activity (i.e., WSRS) on the macrobenthos community around the estuary and suggested that the estuary macrobenthos collected using Agassiz trawls serve as reliable indicators of assessing the impacts of WSRS in the estuary and adjacent waters.