Exploring the hidden fish community and fishery value of estuarine mangroves in western Hong Kong waters through environmental DNA metabarcoding

Estuarine mangroves are a crucial habitat and nursery ground for diverse fish species, playing an important role in supporting the fish stock for local fisheries. To facilitate effective estuarine ecological management and sustainable resource use, a comprehensive understanding of baseline information is essential. However, conventional surveys including fishing gears and underwater visual census are hindered by the shallow and turbid waters of western Hong Kong’s mangroves.

In this project, we propose the use of environmental DNA (eDNA) metabarcoding as a complementary method to uncover the hidden biodiversity and distribution of fish and decapod assemblages in mangrove areas of Hong Kong’s western waters. We will conduct eDNA and conventional surveys simultaneously; compare the efficacy of the two approaches in detecting the common and cryptic species and their diversity; and trace the distribution and seasonality of commercial fishes and decapods in estuarine mangroves. Overall, this study will provide essential baseline information to better understand the current status of fish shocks and support sustainable use of fishery resources in western Hong Kong waters.