Re ECF Project: 2012-12

Project Title: Ecology and biodiversity of benthic dinoflagellates in Hong Kong

Applicant: Dr. WAI Tak-Cheung, State Key Laboratory in Marine Pollution, City University of Hong Kong

Total Approved Grant: $500,000

Duration: 1/6/2014 to 30/4/2016

Project Status/Remarks: Completed

This project aims to conduct baseline ecological studies and document the biodiversity, habitat and substrate associations of marine benthic dinoflagellates in Hong Kong. The findings are intended to provide useful baseline reference for further studies including isolation of benthic dinoflagellates for culture collection, genetic resources development, toxin detection, and relationships between benthic dinoflagellates and environmental changes, and also for long-term monitoring and risk assessment of bloom-forming and toxic benthic dinoflagellates in subtidal ecosystems.

Summary of the Findings/Outcomes:
A total of 28 sites were surveyed from June 2014 to December 2015 and species diversity and abundance of benthic dinoflagellates were monitored quantitatively or qualitatively. To study the spatial variations of diversity of the benthic dinoflagellates, sampling surveys were conducted 3 times in wet (June - October) and dry (December - April) seasons at 3 rocky and 4 coral sites by scuba diving. As the original planned sampling method was not applicable to all rocky and coral sites, which made spatial comparison not possible; a modified bilge pumping method was developed and used for sampling benthic dinoflagellates. Dinoflagellates were isolated individually from field samples for monoculture, and a culture collection/database was established at State Key Laboratory in Marine Pollution, City University of Hong Kong (SKLMP, CityU). The cultured dinoflagellates were then subjected to phylogenetic analysis for species identification. Based on morphological and phylogenetic analyses, a total of 24 species (with 14 benthic species) were identified. This study showed that Coolia spp. were the most dominant benthic dinoflagellates in coral and rocky habitats in both summer and winter, they were found to coexist with other toxin-producing benthic dinoflagellate genera (such as Ostreopsis, Prorocentrum, Amphidinium and globular Gambierdiscus -Fukuyoa) in local marine habitats. A benthic dinoflagellate culture collection and its molecular database were established at SKLMP, CityU. Presentations of findings were given in 3 international conferences.