Macrobenthic communities in Hong Kong waters: Comparison between 2001 and 2012 and potential link to pollution control

Highlights: • Macrobenthos can be used as indicators of environmental quality. • We compared macrobenthos collected in 2001 and 2012 across Hong Kong waters. • Cluster analysis revealed four station groups of macrobenthos in both surveys. • Temporal changes in benthic communities were noted in two areas of pollution control. • Communities in eastern Victoria Harbour and outer Deep Bay showed signs of recovery. - Abstract: Macrobenthic communities in 2001 and 2012 were compared across the marine environment of Hong Kong based on sediment grab samples collected from 28 stations. CLUSTER analysis showed in both surveys that the stations could be divided into four groups at 20% faunal similarity. However, there were notable changes in the macrobenthic community structure between 2001 and 2012 in three focal areas of pollution control (i.e., Victoria Harbour, Deep Bay and Tolo Harbour). The potential link between macrobenthos and pollution abatement measures, and the contributions of environmental conditions to the differential responsiveness of macrobenthos were explored. Notably, a reduction in nutrient input to the eastern part of Victoria Harbour might have led to recovery of benthic communities therein.