Escalating endangerment for North American freshwater fish: nearly 40 percent now at risk

US Geological Survey: Nearly 40 percent of fish species in North American streams, rivers and lakes are now in jeopardy, according to the most detailed evaluation of the conservation status of freshwater fishes in the last 20 years. The 700 fishes now listed represent a staggering 92 percent increase over the 364 listed as "imperiled" in the previous 1989 study published by the American Fisheries Society. Researchers classified each of the 700 fishes listed as either vulnerable (230), threatened (190), or endangered (280). In addition, 61 fishes are presumed extinct.

The new report, published in Fisheries, was conducted by a U.S. Geological Survey-led team of scientists from the United States, Canada and Mexico, who examined the status of continental freshwater and diadromous (those that migrate between rivers and oceans) fish. "Freshwater fish have continued to decline since the late 1970s, with the primary causes being habitat loss, dwindling range and introduction of non-native species," said Mark Myers, director of the USGS. "In addition, climate change may further affect these fish."

The groups of fish most at risk are the highly valuable salmon and trout of the Pacific Coast and western mountain regions; minnows, suckers and catfishes throughout the continent; darters in the Southeastern United States; and pupfish, livebearers, and goodeids, a large, native fish family in Mexico and the Southwestern United States…..

A threatened sicklefin redhorse from the Tennessee River. Photo courtesy of Steve Fraley, North Carolina Wildlife Resources Commission -- from the US Geological Survey web page