Spatio-temporal variation of subtidal macrobenthic fauna and the ecological assessment of Longkou Artificial Island construction in Bohai Sea, China

Abstract

To evaluate the status and changes of macrobenthic communities related to the construction of the Longkou Artificial Island (LAI) in the Bohai Sea, China, four annual surveys were conducted from 2010 to 2013. Significant changes on environmental variations and macrobenthic communities were observed in 2013 after the LAI construction a couple of years later. The changing environment was primarily presented by lower values of pH, dissolved oxygen (DO), organic material (OM) percentage, and higher salinity, suspended particulate matter (SPM) concentration and oil concentration. The main dominant species shifted from Polychaeta taxa in 2010 to Mollusca taxa in 2013 due to the changes of environmental variables. An apparent miniaturization tendency in body size of macrobenthic species was presented from 2010 to 2013. The biodiversity indices increased yearly from 2010 to 2013. However, inter-site homogenization was observed in both the community structure and health status. Multivariate AZTI Marine Biotic Index (M-AMBI) analysis showed that the health status of stations changed depending on its original status and distance to the LAI. However, no significant differences were found in the spatial distribution of either environmental variables or abundance, biomass and biodiversity of macrobenthic communities. All the results will provide a basis for the long-term ecological assessment of reclamation.