WASHINGTON — Recent research published on Wednesday reveals that nearly 25% of animal species inhabiting freshwater environments such as rivers, lakes, and ponds are at risk of extinction.
According to co-author Patricia Charvet, a biologist from Brazil’s Federal University of Ceará, significant waterways like the Amazon may appear robust, yet freshwater ecosystems are notably delicate.
These freshwater habitats, which encompass rivers, lakes, ponds, streams, bogs, and wetlands, occupy less than 1% of the Earth’s surface yet host around 10% of its animal species.
Catherine Sayer, a zoologist with the International Union for Conservation of Nature in England, pointed out that researchers assessed approximately 23,500 species, including dragonflies, fish, and crabs, all reliant on freshwater ecosystems.
The findings indicate that 24% of these species are currently vulnerable, endangered, or critically endangered, facing multiple threats including pollution, dam construction, water diversion, agricultural practices, invasive species, climate change, and other environmental disruptions.
Sayer noted that most species encounter several combined threats concerning their survival, rather than just a singular risk.
This assessment, detailed in the journal Nature, marks the first comprehensive analysis of extinction risks faced by freshwater species globally. Previous research primarily concentrated on terrestrial animals such as mammals, birds, and reptiles.
Stuart Pimm, an ecologist from Duke University who did not take part in the study, praised the work as “a long-awaited and hugely important paper.”
He highlighted that nearly every major river in North America and Europe has been significantly altered by damming, which subsequently jeopardizes freshwater species.
In the context of South America, the Amazon River system confronts significant threats stemming from deforestation, wildfires, and illegal gold mining activities, according to Charvet.
The use of illegal fires to clear forested areas leads to the introduction of ash into water bodies, while unregulated gold mining results in mercury contamination of aquatic environments.
Charvet emphasized that rivers and wetlands effectively act as collectors for everything that occurs in their vicinity.
She warned that severe environmental incidents, such as acid or oil spills, could jeopardize entire species, underscoring that these creatures have no alternative habitats to escape to.
