Nearly a quarter of freshwater species, from fish to dragonflies, are at high risk of extinction worldwide, scientists warn.
Research shows that the rise of chemical and sewage pollution, excessive water extraction and invasive species all increase the likelihood that thousands of species of creatures will be wiped out.
The global assessment of freshwater animals was conducted based on the International Union for the Conservation of Nature (IUCN) Red List of Threatened Species.
It assessed the extinction risk of 23,496 freshwater fish species, dragonflies, damselflies, crabs, crayfish and shrimp.
The study published in the journal Nature found that 24 percent of freshwater animals – at least 4,294 of the species studied – were at high risk of extinction.
Pollution, mainly from agriculture and forestry, affected more than half of the people at risk.
Freshwater habitats are also damaged by land conversion for agriculture, water extraction and dams that also block fish migration, while overfishing and the introduction of invasive non-native species mainly lead to extinctions.
Rivers, lakes, streams and freshwater wetlands provide important habitat and are home to more than a tenth of all known species, including about a third of vertebrates and half of animals, even though they cover less than 1 percent of the Earth’s surface. conservationists warned.
It found that the largest number of threatened species are in four places, including Lake Victoria, Africa’s largest lake
Lake Titicaca in South America was found to be rich in some of the largest numbers of endangered species
The Western Ghats of India is another area that has been discovered to be home to large numbers of endangered species
More than a third of the world’s wetlands (35 percent) were lost between 1970 and 2015, a rate three times faster than that of the world’s forests, while 37% of major rivers flowing more than 1,000 kilometers are tall, no longer free-flowing along their full length, the study warned.
It found that the largest number of threatened species are in Lake Victoria, Africa’s largest lake, Lake Titicaca in South America, Sri Lanka’s wet zone and India’s Western Ghats.
The diversity of freshwater species provides essential services such as flood control, tackling climate change and processing nutrients, and supports the culture and livelihoods of billions of people around the world.
But until now, a comprehensive analysis of the risk of extinction faced by species that live mainly in freshwater has been lacking, using data on animals that live mainly on land to guide environmental action, according to the study co-authored by the IUCN.
IUCN Freshwater Biodiversity lead author Catherine Sayer, lead author of the paper, said: ‘Freshwater landscapes are home to 10 percent of all known species on Earth and are critical for safe drinking water, livelihoods, flood control and climate of billions of people. change mitigation, and must be protected for both nature and humans.”
The assessment found that crabs, crayfish and shrimps are at the highest risk of extinction of the groups studied, with 30 percent threatened, followed by 26 percent of freshwater fish species and 16 percent of dragonflies and damselflies.