Description
Biodiversity and toxicity of benthic dinoflagellates in a subtropical reef ecosystem: the first comprehensive study in Hong KongVeronica T.T. Lam, Sam K.F. Yiu, Priscilla T.Y. Leung, Meng Yan,
Tak-Cheung Wai, Paul K.S Lam
Abstract:
Harmful algal blooms (HABs) is a global issue, marine benthic dinoflagellates are well known as one of the causative agents for the red tides and/or seafood poisoning associated with the HABs. This is the first comprehensive study on benthic dinoflagellates in Hong Kong, aimed to investigate the biodiversity and toxicity of benthic dinoflagellates inhabiting coral and rocky reefs. Samples collected from 28 sites by scuba divers were examined in laboratory; single dinoflagellate cells were isolated for algal culture. Over 200 dinoflagellate cultures have been established. A total of 19 benthic species (of 5 genera Amphidinium, Coolia, Fukuyoa, Ostreopsis and Prorocentrum) were confirmed by morphological and molecular analyses, including three putative new species namely Fukuyoa sp. HK Type 1, Prorocentrum sp. HK type 1 and 2. Over 70% of these species were found potentially toxic to biota, using Artemia larvae, sea urchin larvae and fish blood hemolysis bioassays. Based on Artemia bioassay, Prorocentrum cf. lima and Fukuyoa sp. HK Type 1 were classified as highly toxic species, which caused high mortality rate of Artemia at both high and low doses of algal extracts. Fukuyoa species were toxic to local sea urchin larvae. Amphidinium carterae cause high percentage of Artemia mortality and fish hemolysis. All these results showed that most of the local benthic dinoflagellates are toxic to marine invertebrate and fish, and potentially cause negative effect on the marine ecosystem once HABs occur. Further studies of their toxin profiles and toxicity are still under investigation.
| Period | 6 Jan 2019 → 11 Jan 2019 |
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| Event type | Conference |