Reported inland capture fisheries production increased steadily from 1984, to peak in 1990, and thereafter stabilised at about 6.5 million mt. However, catches from informal activities, particularly subsistence fisheries, are seriously under-reported. Actual catches may be at least twice the reported figure. There are, therefore, dangers with assessments based solely on reported catches. The production is almost entirely fin-fish, with negligible amounts of crustaceans or molluscs, except in localised areas.
Freshwater fish is mainly consumed in its entirety, with practically no discards and minimal wastage. Produce is rarely exported, but consumed domestically, usually by local communities, but it can be transported over large distances. Whilst the reported inland catch represents a modest 7% of capture fishery production, in a significant number of countries there are no marine fisheries at all and current and potential production arises entirely from freshwaters.
Inland capture fisheries are complex in nature involving a wide variety of activities undertaken by people from the widest spectrum of socio-economic backgrounds. Main fishing areas are rivers in major basins, often associated with extensive areas of floodplain in the tropics, lakes, reservoirs and an array of smaller rivers, irrigation and drainage canals and a variety of seasonal or permanent small water bodies.
In general, African freshwater resources are dominated by major rivers and floodplains and the Great Lakes. In South America, lakes are less important but the region has the largest of the world's river basins. Asia has a number of impressive river systems but artificial impoundments, especially large reservoirs, are more prominent than in Africa or South America. In Europe, North America and other developed regions freshwater resources are varied but many rivers have regulated flows and fisheries management systems are becoming increasingly governed by recreational considerations.
Catching methods, on the whole, are dominated by labour intensive gears used on an individual basis, or by small groups; high efficiency commercial gears are rare. This, coupled with the high level of artisanal and informal activity, leads to a high degree of participation, including a significant number of women and children in some regions. It is this level of participation, particularly amongst low income and/or resource poor groups, that is the most important aspect of inland fisheries in relation to food security. The significance of freshwater catches to food security far exceeds what production figures alone might suggest. The overriding tendency for local consumption of the product, with negligible discards and limited wastage, is testament to the value of the product amongst local communities. In some regions inland waters produce a relatively high value product and the relevance of the catch to food security stems from its commodity value.
In many other regions, however, freshwater fish represent an essential, and often irreplaceable source of high quality, and cheap, animal protein crucial to the balance of diets in marginally food secure communities.
Notwithstanding the importance of informal aspects of inland fisheries, there are also a significant number of important commercial/artisanal fisheries in many regions. Fisheries in some of the larger open water regions, for example, resemble marine industrial fisheries and the problems and management requirements are similar. A significant number of fisheries in other areas are equally as important as these in generating income and employment.
Environmental impacts arising from other sectors are the major constraint to sustaining, or increasing, production. These effects can be reduced by improved integrated resource management, incorporating a basin-wide approach to multiple use considerations for freshwater resources. At most risk from these impacts are those communities in areas of high population density presently living on relatively unregulated floodplains, or near major lakes where catchment degradation is escalating. Where opportunities for participation in the development activities that fuel these environmental changes are limited, localised food insecurity will become a fact.
Regional differences exist as to how environmental changes are likely to arise. In the developed world, and in increasingly affluent industrialising economies, rehabilitation of freshwaters is driven by recreational demands in particular. In Eastern Europe (including the former States of the Soviet Union) and much of Asia, without improved mitigation, the effects of predicted rapid economic development will likely severely impact freshwaters, especially through industrial effluents entering rivers. In Africa, the main impacts are likely to arise through population pressures including increased land degradation, through agricultural intensification, especially near the Great Lakes. By comparison, environmental changes in rivers in South America, where lakes are less important, may be less dramatic than in Asia. Localised impacts arising from rapid industrialisation, including mining, can be anticipated. Agricultural intensification is leading to changes in vegetation cover which may inevitably result in shifts in the ecology of much of South America's flowing waters.
Decisions relating to the allocation of water resources need to incorporate multiple use considerations for aquatic resources. For this to occur on a fair and equitable basis, and on sound economic grounds, governments need to gather more information on the current value and utilisation of freshwater habitats. Fishers should, generally, have improved legal access rights to resources. Where projects will have major impacts on freshwater resources, governments need to make clear and unambiguous decisions on whether or not they wish to keep the resources in question.
Often, such issues must be considered in pragmatic terms. In many cases, political decision making processes need national infrastructures able to provide, sectorally impartial, technical advice regarding the various development options available. Most major fisheries have reached, or exceeded, their maximum sustainable yields, unless enhanced. Whilst there are possibilities for increased production from some areas, through improved gears and management, these may be offset by decreases in production from others brought about by over-exploitation, habitat destruction and/or water pollution.
Hence, absolute world production may be sustained to the year 2010, but this scenario masks important localised anomalies that are likely to occur.
Considerable potential exists for increasing catches on a local scale by rehabilitating freshwater habitats and, hence, the fisheries they support. This has already led to improved fisheries in many countries, including developing or industrialising nations, and is being considered as a serious option in many others.
The greatest potential for increasing catches from inland waters is by applying and/or improving culture enhancement techniques. These stocking activities offer particular promise for small water bodies and reservoirs. Stocking is already contributing to a major proportion of the catch from inland waters in many regions, particularly in Asia. The divisions between capture fisheries and culture enhancement activities will rapidly fade and, in many regions, have already gone.
Estimates of biological potential for stocking suggest that, for most areas, this will not be the major constraint, whereas, socio- economic potential, and constraints, vary considerably between regions. Estimates of realistic increases in production that can be achieved through intensified stocking activities are in excess of 5 million mt per annum from existing water-bodies. New reservoirs will present further opportunities for increased production. Where stocking activities are intensified and/or combined with the enhancement of primary production (through, for example, nutrient enrichment of water) increases in production may be well in excess of this.
Improving production through culture-enhanced fisheries has several other attractions including: existing water resources are used; low resource input systems are involved; using species low in the food chain can help maximise the biological efficiency of production; increased participation; beneficiaries are often low income, resource poor, communities; no pollution; and, limited management inputs into the rearing process. Increases in production do not require any major technological changes; management requirements are well known, and not technically complex. Most importantly, the management requirements for increased production through stocking are unlikely to result in conflicts of interest since the process involves enhancing existing activities. Therefore, the prospects for achieving this increased production are excellent.
Issues relating to the ownership of, or access rights to, the stock will constrain private sector involvement in increasing production through stocking. Many of the areas with major potential for stocking are open access (in itself not undesirable). In many cases, the institutional or government sector will be required to take the major initiative. This differs from more intensive aquaculture related activities which might be driven more by the private sector.
Hence, institutional or government funding might be directed at stocking activities in preference to more intensive aquaculture. In the longer-term, private sector management, including community-based approaches, should be encouraged, where necessary and appropriate, by resolving resource use or access rights and issues on a fair and equitable basis. Examples of how this can be achieved already exist.