The Impact of Climate Change on Global Aquaculture: A Focus on Heat Stress

Abstract

Aquaculture is one of the fastest-growing sectors of global food production, contributing significantly to nutrition, livelihoods, and economic development, particularly in low- and middle-income countries. However, climate change poses a growing threat to the stability and sustainability of aquaculture systems, primarily due to rising water temperatures and the increasing frequency of extreme weather events. This review examines the diverse impacts of heat stress on aquaculture species and operations globally. It synthesises current knowledge of the physiological, immunological, behavioural, ecological, and socio-economic consequences. Particular emphasis is placed on metabolic disruptions, oxidative damage, immune suppression, changes in microbiota, and reduced growth and reproductive capacity under both acute and chronic thermal exposure. The regional vulnerability of aquaculture systems is discussed, highlighting disparities in adaptive capacity and resilience. The review further outlines adaptation and mitigation strategies, including thermal tolerance breeding, recirculating aquaculture systems (RAS), precision farming, and climate-smart management practices. It identifies critical research gaps regarding long-term adaptation, early-life exposure effects, and multi-stressor interactions under climate change scenarios. Strengthening science-policy integration and supporting small-scale producers through innovation and investment are key recommendations to enhance climate resilience in aquaculture. Keywords: Climate change, aquaculture, heat stress, thermal tolerance, fish physiology, immune function, adaptation strategies, food security.