Nearly 40 percent of fish species in North America are imperiled, according to a new survey by fish experts, the U. S. Geological Survey, and the American Fisheries Society, up 92 percent from the last survey done in 1989.
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No single cause explains the ongoing fish losses, Taylor and others agree. Habitat loss, invasive species, diseases, dams, and water contaminants all contribute.

“Fish are kind of canaries in the coal mine,” said Howard Jelks of the USGS and lead author of the report, published in Fisheries. “If you change the water to something that’s not able to support these fish, it’s also not going to be as high quality for recreating, for eating the fish out of these streams, for drawing water that’s ultimately used for drinking, or for other things.”