The oceans are vital for production of food from fisheries and aquaculture, but their ability to provide this service is sensitive to climate change and associated ocean acidification. A briefing from the University of Cambridge based on the IPCC Fifth Assessment Report explores the challenges and opportunities climate change poses to fisheries and aquaculture. Read some of the key findings below.
Climate change and acidification are altering ocean ecosystems in profound ways, with consequent impacts on fisheries and aquaculture. Drivers include rising water temperature, rising levels of carbon dioxide (CO2) uptake from the atmosphere and hypoxia (inadequate oxygen).
Projected impacts on fisheries and aquaculture are negative on a global scale; severely so in many regions. Major impacts include displacement of stocks and, for aquaculture, mortality of shellfish from acidic water. However, in some regions, fish stocks are projected to increase.
Impacts of climate change and ocean acidification are generally exacerbated by other factors such as overfishing, habitat loss and pollution. This is contributing to an increase in the number of ‘dead zones’ in the ocean, as well as to an increase in harmful algal blooms.
Coral reef ecosystems are declining rapidly, with the risk of potential collapse of some coastal fisheries. Incidences of coral bleaching are likely to increase. Aquaculture may be affected through reduced catches of feed-fish and increasing severity of tropical storms and flooding.
Fishers can adapt to some climate impacts. Measures available include reducing non-climate stressors such as pollution; changing fishing pressure, gear or target species; increasing aquaculture; and moving to dynamic management policies. However, the scope for adaptation to some factors (such as ocean acidification) is very limited. Political conflicts over fishing may increase as stocks migrate.