Ecology and Conservation of Large-Bodied Freshwater Catfish: A Global Perspective
Zeb S. Hogan
Abstract.—The order Siluriformes includes some of the largest freshwater fish on Earth, including 5 of the world’s 10 largest obligate freshwater fish species. Large-bodied catfish occur predominantly in large lakes and rivers in North America, South America, Europe, Africa, and Asia. Throughout their range, catfish are an important component of commercial, subsistence, and recreational fisheries. They can also have an important role in the ecosystem as top predators or as indicators of overfishing. Despite their importance, relatively little attention has been given to the conservation status of large-bodied catfish. While certain species are considered endangered, other species have not been assessed, and no global study has been conducted to examine the threats they face or their conservation status. Multiple and combined threats from habitat degradation, dams, water withdrawals, pollution, and overexploitation have led to the decline of many catfish populations. In addition to these threats, large-bodied catfish face an additional set of conservation challenges, including shifting baselines, inadequate knowledge (including lack of taxonomic clarity), and a dearth of protected areas and species conservation plans for freshwater species. Despite these challenges, self-sustaining populations of large-bodied catfish still exist, most notably in free-flowing rivers like the Amazon and the lower Mekong. Efforts to protect the ecological integrity of the Amazon and Mekong and other rivers where large-bodied catfish occur will benefit thousands of species of freshwater fish and millions of people who rely on fish for their livelihoods and food security.