资源环境科技发展态势分析平台

The global freshwater fish catch continues to increase, hitting a new record of 12 million tonnes in 2018 according to this year’s FAO report on The State of World Fisheries and Aquaculture – underlining how important freshwater fish are to the food security and livelihoods of hundreds of millions of people across the world.

Worldwide catches in inland waters have increased steadily year on year and now account for 12.5% of the overall global fish catch – up from just 8% in the late 1990s. The marine catch was estimated at 84 million tonnes.

However, many of the data collection systems for freshwater fish are unreliable, or in some cases non-existent. Significant amounts of fish are consumed locally and not recorded in official statistics. Indeed, the 2012 Hidden Harvest report on small-scale fisheries estimated that the freshwater fish catch was underreported by about 70 percent. Some scientists believe the true figure is even higher.

According to The State of World Fisheries and Aquaculture, China remains the top producer with just under 2 million tonnes in 2018, followed by India, Bangladesh, Myanmar, Cambodia and Indonesia. These top six producers accounted for 57 percent of the total global freshwater catch in 2018.

Africa accounts for a further 25 percent of the global catch and boasts 11 of the world’s top 25 producing countries, including Uganda, Tanzania, Democratic Republic of Congo, Malawi, Kenya and Mozambique. Freshwater fish represent an important source of food security in many African countries, particularly in the case of landlocked and low-income countries.

The combined catches for Europe and the Americas account for 9% of total inland captures, while in Oceania catches are negligible.

The report also identifies the most productive river basins, which include Mekong (15% of total global catch), Nile & Lake Victoria (9%), Irrawaddy (7.8%), Yangtze (6.8%), Amazon (4.3%) and Ganges (3.51%).

Inland rivers, lakes and floodplains support even more fishers, processors and traders than do marine sectors, often as a crucial component of a complex and seasonally variable livelihood. In addition, small-scale fisheries are often culturally important. But small-scale fisheries – both marine and freshwater – are too frequently marginalized in social, economic and political processes and not given due attention in policy.

Meanwhile, FAO is cooperating with the United States Geological Survey to develop a global threat map for freshwater fisheries. This work uses a nested modelling approach to combine global geographical information datasets of 20 identified pressures that influence freshwater fisheries. At the basin scale, the highest threat scores facing inland fisheries, arise from a combination of loss of hydrologic connectivity, water abstraction, high population density, land-use change and pollution.

The majority of the world’s freshwater fishery catch comes from river basins that score 4–5 (47 percent) or 6–7 (38 percent) on the threat index. A further 10 percent comes from the basins with the highest threat scores.

"Linking the threat maps to fishery data at a subnational level will enable more detailed national analysis and planning, especially pointing to areas where there is a need for greater understanding of primary threats and their relationship to fisheries production and fish biodiversity. This would enable national fishery agencies to identify important inland fisheries (or aquatic biodiversity) that are at risk and prioritize appropriate fishery monitoring and management interventions," said the FAO report.