The effect of temperature on physiology, toxicity and toxin content of the benthic dinoflagellate Coolia malayensis from a seasonal tropical region

Xin Li; Meng Yan; Jiarui Gu; Veronica T T Lam; Tak-Cheung Wai; David M Baker; Philip D Thompson; Sam K F Yiu; Paul K S Lam; Priscilla T Y Leung

doi:10.1016/j.watres.2020.116264

The effect of temperature on physiology, toxicity and toxin content of the benthic dinoflagellate Coolia malayensis from a seasonal tropical region

Water Res. 2020 Oct 15:185:116264. doi: 10.1016/j.watres.2020.116264. Epub 2020 Aug 3.

Authors

Affiliations

¹ State Key Laboratory of Marine Pollution, City University of Hong Kong, Hong Kong, China; Department of Chemistry, City University of Hong Kong, Hong Kong, China.
² State Key Laboratory of Marine Pollution, City University of Hong Kong, Hong Kong, China; Research Centre for the Oceans and Human Health, City University of Hong Kong Shenzhen Research Institute, Shenzhen, China; Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai, China. Electronic address: mengyan@cityu.edu.hk.
³ State Key Laboratory of Marine Pollution, City University of Hong Kong, Hong Kong, China.
⁴ State Key Laboratory of Marine Pollution, City University of Hong Kong, Hong Kong, China; Research Centre for the Oceans and Human Health, City University of Hong Kong Shenzhen Research Institute, Shenzhen, China.
⁵ The Swire Institute of Marine Science and School of Biological Sciences, the University of Hong Kong, Hong Kong, China.
⁶ State Key Laboratory of Marine Pollution, City University of Hong Kong, Hong Kong, China; Department of Chemistry, City University of Hong Kong, Hong Kong, China; Research Centre for the Oceans and Human Health, City University of Hong Kong Shenzhen Research Institute, Shenzhen, China; Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai, China.
⁷ State Key Laboratory of Marine Pollution, City University of Hong Kong, Hong Kong, China; Research Centre for the Oceans and Human Health, City University of Hong Kong Shenzhen Research Institute, Shenzhen, China; Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai, China.

PMID: 32791455
DOI: 10.1016/j.watres.2020.116264

Abstract

Coolia malayensis is one of the commonly found benthic dinoflagellates in Hong Kong which can produce biotoxins and threaten the early life stages of marine invertebrates. Seawater temperature has been recognized as one of the primary environmental factors that affect the formation of harmful algal blooms. The present study evaluated the responses of C. malayensis, including growth, toxicity and toxin content (putative analogues of okadaic acid and azaspiracids), after exposure to a range of seven different temperatures (i.e., 16°C, 18°C, 20°C, 22°C, 24°C, 26°C, and 28°C). The highest algal density and specific growth rate were recorded at 24°C. Significantly higher F_v/F_m (maximum quantum yield of PSII) and total phaeo-pigment values were observed in the exponential growth phase at 28°C. The toxicity of the algal extract, which was assessed by the lethality rate of Artemia larvae, increased with temperature. The highest toxin content was detected at the second highest temperature treatment, i.e., 26°C. Overall, temperature had significant effects on the physiological activities and toxicity of C. malayensis. This study has raised attention to the potentially increasing risks posed by toxic benthic dinoflagellates during heat waves in coastal waters.

Keywords: Algal toxin; Climate change; LC-MS/MS; Ocean warming; Photosynthesis; South China Sea.

MeSH terms

Animals
Dinoflagellida*
Harmful Algal Bloom
Hong Kong
Seasons
Temperature