Climate Change Impact on Usable Fish BiomassClimate Change Impact on Usable Fish Biomass According to a report by the Food and Agriculture Organization of the United Nations (FAO), climate change poses significant risks to marine ecosystems and fisheries worldwide. Projections from the Fisheries and Marine Ecosystem Model Intercomparison Project (FishMIP) indicate a potential decline in usable fish biomass by 10 to 30% or more by the end of the century if emissions continue unabated. Regional Impacts Many regions are expected to face biomass declines of over 10% by mid-century, particularly under high-emissions scenarios. Countries heavily reliant on aquatic food or major producers of marine fisheries are likely to be disproportionately affected. Emissions Scenarios Under the high-emissions scenario, which projects global warming of 3-4 degrees Celsius, fish stock declines could reach 30% or more in 48 countries by the end of the century. In contrast, the low-emissions scenario, predicting warming of 1.5-2°C, results in smaller declines or no change in 178 countries. Major Fishing Nations Seven nations with significant fish catches, including China, India, and Indonesia, are projected to experience biomass losses under both emissions scenarios. Asian Impact Most Asian countries and territories are expected to see substantial biomass declines by mid-century regardless of the scenario. Americas Countries and regions in North and South America exhibit diverse impacts. While some areas anticipate increases, others, such as Central and South American nations like Guatemala and Colombia, face steep declines. Europe and Africa Europe, while a major fisheries and aquaculture producer, has mixed projections. Some northern and eastern Mediterranean regions may experience gains, but overall, biomass is expected to decrease. In Africa, most countries will likely see declines, with exceptions in the north and southeast. Oceania Oceania, vulnerable to multiple climate hazards, is projected to experience severe biomass losses. Report Recommendations To mitigate these risks, the report emphasizes improving the accuracy of climate impact models and enhancing the capacity of researchers to meet future policy needs.
According to a report from the Food and Agriculture Organization of the United Nations (FAO), usable fish biomass will decline by 10 to 30 percent or more by the end of the century if emissions are not stopped.
The report, Climate change risks to marine ecosystems and fisheries: projections to 2100 from the Fisheries and Marine Ecosystem Model Intercomparison Projectpresents projections from the Fisheries and Marine Ecosystem Model Intercomparison Project (FishMIP), an international network of researchers working to understand the long-term impacts of climate change on marine ecosystems and fisheries around the world.
Many regions of the world will see declines of more than 10 percent by mid-century, particularly under the high-emissions scenario.
Under the high-emissions scenario, which projects global warming of 3-4 degrees Celsius (°C), fish stock declines will increase to 30 percent or more in 48 countries and territories by the end of the century.
Some of the largest projected declines in biomass occur in countries that are highly dependent on aquatic food protein supplies (Solomon Islands, Federated States of Micronesia, Nauru, Portugal, Palau) or that are the largest producers of marine fisheries products globally (China, Peru).
However, under the low-emissions scenario – which predicts global warming of 1.5-2°C – changes level off between no change and a decline of 10 percent or less in 178 countries and territories by the end of the century.
Seven countries with the largest fish catches, which together accounted for 48 percent of global marine catches in 2022, are likely to experience losses in exploitable fish biomass by the end of the century under both emissions scenarios. These countries are China, India, Indonesia, Peru, Russia, Vietnam and the United States.
Most Asian countries and territories (60 percent) show significant declines in exploitable fish biomass by mid-century regardless of scenario.
Countries and regions in North and South America show large differences in expected changes in exploitable fish biomass.
There has been a sharp decline in exploitable fish biomass for other countries and areas in Central and South America, such as Guatemala, El Salvador, Uruguay, Costa Rica, Nicaragua, Panama and Colombia.
Europe, the world’s third largest producer of fisheries and aquaculture products after Asia and the Americas, shows a mixed picture under both high and low emission scenarios.
While some increases are expected for very high latitudes (Russia) and in the eastern Mediterranean (Greece, Italy and Malta), especially in the high emissions scenario, aggregate trends show a decrease for most countries and areas in both scenarios.
In Africa, most countries and regions are expected to experience a decline in usable fish biomass, with the exception of countries in the northern part of the continent and around some islands in the southeast and southwest (Morocco and Mauritius).
One of the most striking losses of usable fish biomass globally is in Oceania, a region also facing numerous other climate hazards and risks.
The report was published on 10 July 2024 at FAO headquarters in Rome, during the thirty-sixth session of the Commission on Fisheries (COFI36).
It was recommended to improve the accuracy of climate impact ensemble models for marine ecosystems and fisheries. This included building capacity by providing tools and training to increase the ability to meet future policy needs.
