Extreme cold or warm events can potentially exacerbate chemical toxicity to the marine medaka fish Oryzias melastigma

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review

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Author(s)

  • Adela J. Li
  • Guang-Jie Zhou
  • Racliffe W.S. Lai
  • Priscilla T.Y. Leung
  • Chen C. Wu
  • Eddy Y. Zeng
  • Gilbert C.S. Lui

Detail(s)

Original languageEnglish
Article number106226
Journal / PublicationAquatic Toxicology
Volume249
Online published15 Jun 2022
Publication statusPublished - Aug 2022

Abstract

Marine ecosystems are currently subjected to dual stresses of chemical pollution and climate change. Through a series of laboratory experiments, this study investigated the impact of exposure to chemical contaminant such as DDT or copper (Cu), in combination with cold or warm temperature extremes on the marine medaka fish Oryzias melastigma. The results showed that extreme seawater temperatures (i.e., 15 and 32 °C in sub-tropical Hong Kong) exacerbated adverse chemical impacts on the growth performance of O. melastigma, in particular at the high thermal extreme. This was likely associated with an interruption of oxygen consumption and aerobic scope. Most importantly, the results of acclimation experiments, as reflected by thermal tolerance polygons, showed that chemical exposure substantially narrowed the thermal tolerance of the medaka, making them more vulnerable to temperature changes and extreme thermal events. Under dual stresses of thermal extremes and chemical exposure, the medaka switched their metabolic pathway to anaerobic respiration that might deplete their energy reserve for chemical detoxification. Although stress proteins such as heat shock proteins (HSP90) were up-regulated for cellular protection in the fish, such a defensive mechanism was repressed with intensifying dual stresses at high temperature and high chemical concentration. Bioconcentration of DDT or Cu generally increased with increasing temperature and its exposure concentration. Overall, these complex chemical-temperature interactions concomitantly exerted a concerted adverse impact to O. melastigma. The temperature-dependent toxicity of DDT or Cu shown in this study clearly demonstrated the potential challenge brought by the risk of chemical pollution under the impact of global climate change.

Research Area(s)

  • Insecticide, Marine medaka, Metal, Thermal extremes, Toxic mechanism

Citation Format(s)

Extreme cold or warm events can potentially exacerbate chemical toxicity to the marine medaka fish Oryzias melastigma. / Li, Adela J.; Zhou, Guang-Jie; Lai, Racliffe W.S. et al.
In: Aquatic Toxicology, Vol. 249, 106226, 08.2022.

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review