Nearly a quarter of the world's freshwater species are at risk of extinction, according to new research. A detailed extinction assessment of more than 23,000 species of freshwater fauna by the International Union for Conservation of Nature identified major threats from pollution,

A lack of understanding can no longer be used as an excuse for inaction. As the authors of the new study point out, freshwaters support more than 10% of all known species, including about a third of vertebrates and half of fishes, while covering less than 1% of the surface of the Earth.

Freshwater habitats cover less than 1% of the planet's surface but support 10% of its animal species, a zoologist and study co-author says.

Nearly a quarter of animals living in rivers, lakes and other freshwater sources are threatened with extinction, according to new research published Wednesday. “Huge rivers like the Amazon can appear mighty,

Nearly a quarter of species living in freshwater ecosystems like rivers and lakes are threatened with extinction, according to research published Wednesday, AP News reports.

Freshwater environments cover about 1% of Earth’s surface while accounting for more than 10% of known species. Like many marine and terrestrial ecosystems, however, they are in distress. A new study looking at some of the denizens of freshwater habitats offers a stark illustration of this biodiversity predicament.