The impact of suspended oyster farming on macrobenthic community in a eutrophic, semi-enclosed bay: Implications for recovery potential

Abstract

The impact of suspended oyster farming on macrobenthic communities, and their recovery following oyster farm removal, are reported for Xiangshan Bay, China. Sampling was conducted in 2009, 2010, and 2015 to assess: 1) spatial pattern in macrobenthic community structure at progressively increasing distances from farm; 2) spatial and seasonal variability in macrobenthic community structure beneath two farms and a reference site; and 3) potential recovery of macrobenthic community 3 years after cessation of oyster farming. A site located at the edge of a farm had peaks in macrobenthos species richness, abundance, biomass, Shannon–Wiener diversity (H′), and Margalef richness (d). Macrobenthic communities beneath two farms differed significantly from those at a reference site. Significant differences in macrobenthic community structure between farms are attributed to differing hydrological and sedimentary characteristics. Macrobenthos species richness, abundance, H′, and d increased significantly 3 years after oyster farming ceased. The post-fallowing presence of Ampelisca sp., and increased abundances of Heteromastus filiformis and Scapharca kagoshimensis contributed most to differences in macrobenthic communities before and after farming ceased. We suggest that an assessment of the ecological carrying capacity of shellfish aquaculture in Xiangshan Bay is necessary to ensure sustainable, regional aquaculture development.