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 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.