Exploitable fish biomass will decline by 10 to 30 per cent or more by century end if emissions are not stopped, a report released by the Food and Agriculture Organization of the United Nations (FAO) has predicted.
The report, Climate change risks to marine ecosystems and fisheries: Projections to 2100 from the Fisheries and Marine Ecosystem Model Intercomparison Project, presents projections from the Fisheries and Marine Ecosystem Model Intercomparison Project (FishMIP), an international network of researchers working towards understanding the long-term impacts of climate change on marine ecosystems and fisheries around the world.
There will be a decline of more than 10 per cent, particularly under the high-emissions scenario, by mid-century for many regions of the world.
Fish stock decline will worsen to 30 per cent or greater in 48 countries and territories by century-end under the high-emissions scenario, which projects global warming of 3-4 degree Celsius (°C).
Some of the largest projected biomass declines are for countries that substantially rely on protein supply from aquatic foods (Solomon Islands, Federated States of Micronesia, Nauru, Portugal, Palau) or are top producers in terms of global marine fisheries production (China, Peru).
However, under the low-emissions scenario — which projects global warming of 1.5-2°C — changes stabilise between no change and a decrease of 10 per cent or less across 178 countries and territories by the end of the century.
Seven countries with the largest fish catches, which between them accounted for 48 per cent of global marine captures in 2022, will likely experience losses in exploitable fish biomass by century-end across both emissions scenarios. These countries are China, India, Indonesia, Peru, Russia, Vietnam and the United States.
Most Asian countries and territories (60 per cent) show significant declines in exploitable fish biomass under both scenarios by mid-century.
Countries and territories of North and South America show wide variation in projected changes in exploitable fish biomass.
There are strong declines in exploitable fish biomass for other countries and territories in Central and South America, such as Guatemala, El Salvador, Uruguay, Costa Rica, Nicaragua, Panama and Colombia.
Europe, the world’s third largest fisheries and aquaculture producer after Asia and the Americas, shows a mixed picture under the high and low emissions scenarios.
While some increases are projected for very high latitudes (Russia) and in the Eastern Mediterranean Sea (Greece, Italy and Malta), particularly under the high emissions scenario, aggregated trends reveal declines for most countries and territories under both scenarios.
In Africa, most countries and territories are expected to experience declines in exploitable fish biomass, except those in the northern part of the continent and around some south-eastern and south-western islands (Morocco and Mauritius).
Some of the most pronounced losses in exploitable fish biomass globally are evident for Oceania, a region that faces numerous other climate hazards and risks.
The report was released on July 10, 2024, at FAO headquarters in Rome, during the Thirty-sixth session of the Committee on Fisheries (COFI36).
It recommended improving the accuracy of climate impact ensemble modelling for marine ecosystems and fisheries, including building capacity through provision of tools and training to enhance capabilities for meeting future policy needs.