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.

Seasonal differences in thermal stress susceptibility of diploid and triploid brook trout, Salvelinus fontinalis (Teleostei, Pisces)

“…Similar to decreased rates of fish maintaining equilibrium, decreased growth rates are an indication that temperature is outside the optimal range (Pfalzgraff et al ., 2021; Volkoff & Rønnestad, 2020). Elevated temperature influences growth rates through an increase in metabolic turnover rate (Islam et al ., 2021) and in the stress hormone cortisol (Chadwick & McCormick, 2017; Islam et al ., 2021). Elevated cortisol levels reduce appetite and feed conversion efficiency and digestibility of proteins and lipids (Pfalzgraff et al ., 2021).…”

Aquaponics as a Promising Strategy to Mitigate Impacts of Climate Change on Rainbow Trout Culture

“…Farmed rainbow trout requires certain environmental factors (temperature, pH, and dissolved oxygen) for its normal growth and welfare [ 38 , 39 ]. With the intensity of climate change, in recent years, these environmental factors have gradually shifted, affecting the welfare and health of rainbow trout [ 40 , 41 ]. For this reason, researchers chose to use the rainbow trout as an experimental model against climate change based on its capability to tolerate a wide range of environments and handling procedures [ 40 , 41 ].…”

“…Specifically, when the temperature rises, the oxygen content of the water generally decreases, while the oxygen consumption of the fish increases. Climate change leads to a reduction in the minimum oxygen consumption (5mg/l) and a decrease in the pH value of water (pH 3) [ 41 , 53 , 54 ]. This implies that the fish cannot feed effectively and, therefore, extremely high temperatures of the water will block the growth rate of the fish and cause health problems [ 54 ].…”

Horizon Scan on the Benefits of Ocean Seasonal Forecasting in a Future of Increasing Marine Heatwaves for Aotearoa New Zealand

“…MHWs have also caused the collapse and/or closure of wild fisheries in recent years (e.g., Caputi et al, 2019). Caged fish farm production may be reduced if fish are stressed by unfavorable conditions (Islam et al, 2021;IPCC, 2022) and unusually warm waters have been implicated in shellfish crop failure (Keeling et al, 2014;Broekhuizen et al, 2021;King et al, 2021). While there may also be some positive impacts, in all these cases there are a range of complexities and uncertainties requiring more data and process understanding (Smith et al, 2021;Tait et al, 2021).…”