Shallow marine ecological degradation in Hong Kong: a palaeoecological approach using ostracods

Abstract

Hong Kong is one of the largest and most rapidly developing cities in Asia. It is known that the marine ecosystems of Hong Kong have been seriously influenced by a variety of anthropogenic factors, including eutrophication, bottom trawling, coastal reclamation, pollution, etc. However, little is known about long-term history of such human-induced marine ecological degradation in Hong Kong. Here we use microfossil ostracod as a model system and compare among top-1-cm (representing live or recently dead assemblages) and whole (representing averaged state of assemblage for the past several decades) assemblages in grab samples and Holocene background assemblages in a long sediment core. Preliminary ostracod results showed that discrepancy between top-1-cm and whole assemblages is larger in urban sites and smaller in rural sites. Furthermore, species diversity of Holocene background assemblage was much higher than diversities in grab samples. Faunal composition of Holocene sample was also distinct from faunal assemblages of grab samples. These results clearly indicate serious ecological degradation during the past several decades, potentially reflecting recent humaninduced eutrophication. Full results will be shown in the presentation.