Illustrative picture of endangered freshwater animals
Credit: © Sarah Streyle - Conservation International.
By AFP - Agence France Presse
A quarter of freshwater species are facing extinction: Study
A quarter of freshwater animals, including fish, insects, and crustaceans, are at high risk of extinction due to threats such as pollution, dams, and agriculture, according to a new study published on Wednesday.
Freshwater - including rivers, aquifers, lakes, and wetlands - covers less than one percent of the Earth's surface, but is home to more than 10 percent of known species, including half of all fish and a third of all vertebrates.
This diversity sustains the livelihoods of billions of people and is a bulwark against climate change, but the study, published in the peer-reviewed academic journal Nature, says it is under “substantial stress.”
A new assessment covering more than 23,000 freshwater species found that 24% of the total were threatened with extinction, with variations between the groups studied.
Around 30% of decapods—such as shrimp, crabs, and crayfish—were at risk, compared to 26% of fish, 23% of tetrapods, including frogs and reptiles, and 16% of odonates, such as dragonflies.
Since 1500, around 89 freshwater species have become extinct and it is suspected that another 178 will suffer the same fate.
The authors write that these figures are likely underestimated because too little is known about certain species.
There is “an urgent need to act quickly to address the threats to prevent further declines and species losses,” they wrote.
Pollution, dams and water extraction, changes in land use and agriculture, invasive species and diseases, climate change, and extreme weather conditions were the main threats to freshwater species.
The decline of freshwater sources occurs “generally out of sight and out of mind, despite the importance” of these critical habitats and climate regulators.
Around 35% of wetlands, such as marshes, swamps, and ponds, were lost between 1970 and 2015, a rate three times faster than that of forests, according to the study.
The decline of freshwater sources occurs “generally out of sight and out of mind, despite the importance” of these critical, climate-regulating habitats.
Around 35% of wetlands, such as marshes, swamps, and ponds, were lost between 1970 and 2015, a rate three times faster than that of forests, according to the study.
Around a third of rivers over 1,000 kilometers long (620 miles) are no longer flowing freely for their entire length, it added.
“Until recently, the freshwater domain has not received the same priority as the terrestrial and marine domains in global environmental governance,” the authors wrote.
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