A quarter of freshwater fish at risk of extinction, assessment reveals

A new assessment discovered that 25 percent of freshwater fish are at risk for extinction due to climate change and pollution.

The latest update to the International Union for Conservation of Nature’s (IUCN) Red List of Threatened Species was published Monday and included the first-ever global assessment of freshwater fish. It found that 3,086 out of 14,898 assessed species — 25 percent — are at risk of extinction.

The assessment found that 17 percent of threatened freshwater fish species are affected by climate change, which includes shifting seasons, decreasing water levels and rising sea levels. The rising sea levels can lead to more seawater moving up rivers and therefore affecting the freshwater species.

It also found that pollution affects 57 percent of freshwater fish that are at risk for extinction.  Dams and water extraction impacts 45 precent of threatened freshwater fish, overfishing threatens 25 percent and invasive species and disease put 33 percent at risk, according to the assessment.

The latest update also warned that the Atlantic salmon is facing increasing threats to their habitats. It said that new evidence suggested that the global population of the species dropped 23 percent between 2006 and 2020.

Now, the threat level of the Atlantic salmon has been moved from “Least Concern” to “Near Threatened.” It pointed to climate change, dams and invasive species as the reasons for the declining population.

Kathy Hughes, co-chair of the IUCN SSC Freshwater Fish Specialist Group, said that freshwater ecosystems must be “well managed” to “maintain food security, livelihoods and economies in a climate resilient world.”

“Freshwater fishes make up more than half of the world’s known fish species, an incomprehensible diversity given that freshwater ecosystems comprise only 1 percent of aquatic habitat,” Hughes said in a statement. “These diverse species are integral to the ecosystem, and vital to its resilience. This is essential to the billions of people who rely upon freshwater ecosystems, and the millions of people who rely on their fisheries.”