Impact of environmental factors changes induced by marine heatwaves and heavy precipitation on antibiotic toxicity to Isochrysis galbana: Implications for climate change adaptation

Canace C Y Wat; Xiaying Xin; Racliffe W S Lai; Xuemei Mao; Kenneth M Y Leung

doi:10.1016/j.marpolbul.2024.116453

Impact of environmental factors changes induced by marine heatwaves and heavy precipitation on antibiotic toxicity to Isochrysis galbana: Implications for climate change adaptation

Mar Pollut Bull. 2024 May 11:203:116453. doi: 10.1016/j.marpolbul.2024.116453. Online ahead of print.

Authors

Canace C Y Wat¹, Xiaying Xin², Racliffe W S Lai³, Xuemei Mao⁴, Kenneth M Y Leung¹

Affiliations

¹ State Key Laboratory of Marine Pollution and Department of Chemistry, City University of Hong Kong, Kowloon 999077, Hong Kong, China.
² Beaty Water Research Centre, Department of Civil Engineering, Union Street, Queen's University, Kingston K7L 3Z6, Canada. Electronic address: x.xin@queensu.ca.
³ Department of Ocean Science and Technology, Faculty of Science and Technology, University of Macau, Macau.
⁴ Environmental Microbiome Engineering and Biotechnology Laboratory, Department of Civil Engineering, The University of Hong Kong, Pok Fu Lam, Hong Kong, China.

PMID: 38735174
DOI: 10.1016/j.marpolbul.2024.116453

Abstract

Isochrysis galbana, a crucial primary producer and food source in aquatic ecosystems, faces increasing challenges from climate change and emerging contaminants like antibiotics. This study investigates the combined effects of sudden temperature increase (representing marine heatwaves) and rapid salinity change (representing extreme precipitation events) on the toxicity of tetracycline (TC) and oxytetracycline (OTC) to I. galbana. Short-term experiments reveal heightened antibiotic toxicity at 31 °C or salinities of 18 PSU, surpassing algal tolerance limits. Long-term tests show decreased inhibition of algal growth on day 9, indicating algal adaptation to the environment. Analyses of photosynthesis II efficiency, pigment content, and macromolecular composition support this, suggesting adaptation mechanism activation. While algae acclimate to the environment during long-term antibiotic exposure, extreme weather conditions may compromise this adaptation. These findings have implications for managing antibiotics in aquatic environments under climate change.

Keywords: Antibiotics; Environmentally relevant concentrations; Heat wave; Heavy precipitation; Marine algae.