Decadal change in sublittoral macrofaunal biodiversity in the Bohai Sea, China

The region of the Bohai Sea is among the most densely populated of any marginal sea worldwide, and the sea is of great commercial importance as one of the major fishing areas in China. In this study, sublittoral macrofaunal community data collected during the 2000s was integrated with historical data from the 1980s to 1990s to detect any change in biodiversity status over the past three decades. Biodiversity was assessed through species diversity, taxonomic relatedness and other measures of community structure. Different geographic locations had different scenarios of decadal biodiversity change. We observed a sustained increase in species diversity in Bohai Bay and a cyclic trajectory in Laizhou Bay. In the central part of the Bohai Sea, there was little change in species diversity, whereas taxonomic distinctness tended to increase. A test for departure from the expected value of taxonomic distinctness (Δ+, Λ+) suggested that approximately one-fifth of the sampling stations were subjected to environmental stress and perturbation.