Evaluation of threats faced by benthic invertebrates in Hong Kong wetland using micropaleontological and neontological approach

Anthropogenic impacts ranging from pollution, introduction of invasive species and human induced climate change have been synergistically impacting wetland ecosystems in complex ways. In Hong Kong, Gei wai is one of the major wetland management strategies used for decades which has both cultural significance, and environmental benefits. Used for rearing shrimps as a fishery, the gei wai’s create stable habitats with diverse characteristics suitable for the shrimp and many invertebrate and vertebrate species – creating the foundation for complex food chains benefiting higher feeding guilds, and enhancing overall biodiversity. Benthic invertebrates are the major taxa supporting the wetland ecosystem. Yet, the ecology in gei wai has been under-studied whether from the synergistic effects of multiple stressors, or from emerging individual threats. In addition, some of the benthic invertebrates such as Golden Apple Snails (Pomocea canaliculata) are found to be invasive alien species, posing threats to the wetland ecosystem as they are widespread, and abundant.

In our study, we have adopted neontological and paleoecological approaches to study the spatio-temporal patterns of ostracods (Crustacea) and foraminiferas (Protista) in the gei wais in Mai Po Nature Reserve, aiming to elucidate the controlling factors of benthic invertebrates’ species diversity. In our preliminary study, we have observed a lower species diversity of foraminifera in gei wai infested by Golden Apple Snails. We will present our preliminary results in this paper.

Keywords: wetland biodiversity, benthic invertebrates, gei wai, environmental change, micropaleontology