Peter Moyle: Fresh water makes up one-hundredth of one percent of the water on the planet. That’s just a tiny little amount, and we humans of course depend on that water – and so do the fish.
Peter Moyle is an expert on freshwater fish – the fish that live in lakes and streams around the world. Moyle, who works at University of California – Davis, said many freshwater fish species are in trouble. He discovered this when he analyzed fish population data from the International Union for the Conservation of Nature.
Peter Moyle: The estimate that we’re coming up with for the percentage of the world’s freshwater fish fauna that’s in serious trouble is between 30-50%. Somewhere between four thousand and seven thousand species are expected to go extinct in the reasonable future, if present trends continue.
Moyle estimates that’s 50 to 100 years from now. He told EarthSky that the freshwater fish decline reflects the poor health of the planet’s fresh water systems.
Peter Moyle: We have pollution, we have massive changes to the rivers caused by dams, we introduce non-native species, we alter our lakes and rivers to accommodate cities and farms. It basically means we’re stressing the fresh waters of the world to their limits.
Moyle said that all countries all around the world are being affected.
Peter Moyle: What you find is the countries with the highest percentage of endangered species are the highly industrialized countries like the United States, or they tend to be countries that are in dry areas, or desert countries, but this is not confined to just one or two countries.
Moyle said the stressed fish population reflects the stresses we’re putting on our freshwater systems. Moyle urged immediate action, and added that in California, where he works, 73% of the freshwater fish are currently in severe decline, with a smaller percentage already listed as endangered.
Peter Moyle: We’ve already got 23% of them listed right now by federal or state authorities, so it’s not just me saying this. It’s very real.
Beth Lebwohl researches, writes and helps produce science content in audio and video formats for EarthSky. She is one of the authors on EarthSky.org, a script-writer for our podcasts, and helps host our English science podcasts in 90-second, 8-minute and 22-minute formats. Beth came to EarthSky in 2006 from the American Museum of Natural History's Department of Astrophysics, where she was surrounded by some of the greatest telescope-building, equation-wielding, code-writing physicists of our time. And they made her think . . . this science thing . . . it's pretty cool.