This policy brief, compiled by 16 international agencies, considers what policymakers can do to help fisheries and aquaculture cope with climate change.

Fish and shellfish provide essential nutrition to three billion people worldwide and livelihoods to more than 500 million in developing countries.

But climate change is modifying key environmental factors — including air and sea surface temperatures, rainfall, sea level and ocean acidity — that will change the distribution and numbers of marine and freshwater species and impact fisheries and aquaculture.

In the developing world these systems are already at risk. For example, saltwater intrusion into the Mekong delta in South-East Asia threatens the viability of catfish aquaculture in the region — an industry worth US$1 billion a year that provides livelihoods to more than 150,000 people.

Climate change will likely impact aquatic ecosystems such as mangroves that offer coastal communities protection from natural hazards, and coral reefs that provide wild fish and feed for aquaculture.

Investments are urgently needed to mitigate these threats and adapt to their impacts, says the policy brief. Adaptation measures include adhering to the UN Food and Agriculture Organization (FAO) Code of Conduct for Responsible Fisheries, eliminating subsidies that promote overfishing, raising awareness among local communities, and focusing on herbivorous species to provide nutritious food with a low carbon footprint.

Climate change offers new opportunities for aquaculture as more species are cultured. Shellfish farming can help clean coastal waters, while culturing aquatic plants can remove wastes from polluted waters.

Environmentally friendly biofuel production from seaweed should be encouraged and carbon sequestration options must be explored.

And investment in aquatic science is fundamental, says the policy brief. It argues that our knowledge of aquatic ecosystems and the ocean carbon cycle must be improved if we are to build sustainable and resilient fisheries and aquaculture.

Link to full policy brief from The WorldFish Center