The freshwater habitats, fishes, and fisheries of the Orinoco River basin

The Orinoco River of Venezuela and Colombia is one of the great rivers of the world, ranking third by discharge after the Amazon and the Congo. In the Orinoco basin, riverine and floodplain habitats, including riparian forests, play key roles in the conservation of biodiversity and support commercial, sport, and subsistence fisheries. The basin three major floodplains regulate the amplitude and duration of floods, maintain fertile agricultural terrain, provide habitat for numerous terrestrial and aquatic species, and support the fishery. The fish fauna, which includes some 1, 000 species, encompasses a great deal of ecological diversity in terms of geographic distributions, habitat affinities, functional morphology, and reproductive and feeding strategies. The Orinoco fishery is still multispecific, with around 80 different species found in the fish markets at different times of year Current estimates indicate that annual sustainable yield is 40,000-45, 000 metric tons. Fish culture in the region is underdeveloped despite decades of research and promotion. There is no serious commercial trade for ornamental fishes. Large regions of the Orinoco basin are still in a relatively pristine state, but aquatic resources are increasingly threatened by habitat destruction, overharvesting, pollution, and hydrological perturbation. Scientific understanding of diversity hotspots, critical habitats, and conservation status of fishes in the basin is currently insufficient to satisfy management needs. Compliance to fishery regulations is low and fishing is drastically modifying the relative abundance, population structure, and distribution of fish stocks. However many sectors of the Orinoco basin are unexploited or only lightly exploited, and fish stocks can recover quickly if given the opportunity. Stricter enforcement of current fishery regulations would reduce the likelihood of stock collapses and other possibly irreversible, changes in the fishery.