Responses of aquaculture fish to climate change-induced extreme temperatures: A review

Abstract

Climate change-induced extreme temperature events are becoming more intense and frequent. For fish, temperature is the master abiotic factor that controls and limits fish development and physiology at all stages of aquaculture. Major physiological constraints at the individual level underpin changes in fish growth, hemato-physiology, metabolism, immune and molecular stress responses to extreme temperature events. Extreme temperature impacts on fish vary among and within the diverse species depending on stress magnitude and associated factors. This review synthesizes the impacts of climate change-induced extreme temperature events on neuroendocrine, oxidative, metabolic, osmotic, molecular, hemato-biochemical, and immune responses in fish related to aquaculture. Besides, overall aspects of extreme temperature impacts on fish growth and reproduction are also discussed. Possible mitigation measures to maintain the fish's physiological fitness during extreme temperature events are also addressed. However, studies on the interactive effects of extreme temperature events with other associated environmental stressors are needed across a broader range of species to gain a better understanding of fish response and aquaculture performance during extreme temperature events. Moreover, for fish, studies on alternative species, development of stress-tolerant strains, and the possibilities of nutritional mitigation measures as a potential option to combat extreme temperature stress are promising and should be pursued in future studies.