Fish are a a major source of protein and micronutrients for a large part of the world’s population.
Inland fisheries in rivers, lakes, and wetlands are an important source of this protein because almost the entire catch gets consumed directly by people – there is practically no bycatch or “trash” fish in inland fisheries.
The principal factor threatening inland fisheries is the loss of fish habitat and environmental degradation:
- Threats and issues in North America:
- highly fragmented rivers (caused by dams, canals, and other projects)
- non-point source pollution
- increasing importance of recreational fisheries
- major fisheries depedent on stock enhancement
- increasing attention to river and habitat restoration
- Threats and issues in Central and South America:
- water pollution from mining industry discharges and exanding urban centers
- localized overfishing
- increasing turbidity and sedimentation from agricultural runoff and deforestation
- localized threats from dam construction
- Threats and issues in Europe:
- highly fragemented rivers (caused by dams, canals, and other projects)
- water pollution
- increased importance of recreational fisheries
- some fisheries dependent on stock enhancement
- increasing attention to river and habitat restoration
- Threats and issues in Africa:
- increasing habitat degradation
- loalized water pollution and overfishing
- loalized problems with species introductions
- Threats and issues in Asia:
- habitat degradation
- interference of water flow by construction works
- overfishing and destructive fishing practices
- high dependency on stock enhancement
- Threats and issues in Oceania:
- water pollution fromj pesticide and herbicide runoff
- high sediment loads and rising salinity in inland waters
- increasing importance of recreational fisheries
The following summarizes key findings of the PAGE study regarding the condition of freshwater systems, as well as the quality and availability of data.
Conditions and trends
- In 1997, inland fisheries landings accounted for 7.7 million metric tons, or almost 12 percent of total capture available for human consumption, a level estimated to be at or above maximum sustainable yields. Taking into account the inland capture, fisheries are estimated to be underreported by two or three times, the contribution to direct human consumption is likely to be at least twice as high.
- Freshwater aquaculture currently has a higher production than capture fisheries, contributing 17.7 million metric tons of fish and seafood in 1997. In 1997, marine and inland aquaculture production provided 30 percent of the fish for human consumption; 60 percent of this production comprised of freshwater finfish or fish that migrate between fresh and saltwater.
- At the global level, inland fisheries landings have been increasing since 1984. Most of this increase has occurred in Asia, Africa, and more moderately in Latin America. In North America, Europe, and the former Soviet Union, landings have declined, whereas in Oceania they have remained stable.
- Despite this increase in landings, maintained in many regions by fishery enhancements, such as stocking and fish introductions, the greatest overall threat for the long-term sustainability of inland fishery resources is the loss of fishery habitat and the degradation of the terrestrial and aquatic environment.
- Historical trends in commercial fisheries data for well-studied rivers show dramatic declines over the 20th century, mainly from habitat degradation, invasive species, and overharvesting.
Information status and needs
- Data on inland fisheries landings are poor, especially in developing countries. The FAO database on inland fisheries landings is the most complete data set at the global level; however, it has important limitations. Some of the main problems are that much of the catch is not reported at the species level and much of the fish consumed locally is never reported, making fishery assessment difficult.
- There is no systematic data collection on the contribution of stocking, fish introductions, and other enhancement programs to inland fisheries. This information, as well as information on recreational fisheries, which are becoming increasingly important in many countries, should be incorporated into data collection efforts.
- Reporting on fishery resources at the watershed level instead of the national level, as it has been done to date, would improve our understanding of the condition of the system and the linkages between upstream activities and their downstream effects. This information could then be applied to watershed and fishery resources management plans.
- Historical trends in fisheries statistics are available only for a few well-studied rivers, and because of the multispecies composition of the catch in most inland water bodies, particularly in developing countries, assessments on the condition of the resources are hard to carry out.
Quality and availability of data
PAGE measures and indicators
Data sources and comments
Historical change in fish catch and species composition for selected rivers, lakes, and inland seas Data are from various sources for the following bodies of water: Danube, Rhine, Missouri, Great Lakes, Illinois, Pearl (Xi Jiang), Lake Victoria, Colorado in the United States, and the Aral Sea. All studies looked at either changes in species composition or changes in commercial landings of important inland fisheries.
Recent trends in catch statistics from inland waters Inland capture fisheries data are from the Food and Agriculture Organization of the United Nations (FAO) for the period 1984-97. Inland capture fisheries include freshwater and diadromous fish caught in inland waters, and freshwater molluscs and crustaceans.
