Freshwater ecosystems are among the most vital on Earth, but they’re also some of the most endangered.
Covering less than 1% of the planet’s surface, they support 10% of all known species and provide clean drinking water, food, flood control, and climate regulation.
However, new research published in the journal Nature reveals a shocking statistic: nearly 24% of freshwater species are at risk of extinction.
From fish and crabs to dragonflies and snails, thousands of freshwater species could disappear in the coming decades if urgent action isn’t taken.
Scientists examined the health of almost 24,000 freshwater species and found that nearly 1,000 are critically endangered, with around 200 possibly already extinct.
Alarmingly, these figures may underestimate the problem since researchers still lack enough data on many species.
“Freshwater biodiversity is too important to ignore,” says Catherine Sayer, the study’s lead author. “These ecosystems are crucial for both nature and people, and we need to act quickly to protect them.”
Freshwater environments, like rivers, lakes, and wetlands, face enormous pressure as human demands for water, food, and resources grow.
Wetlands, including bogs, mangroves, and saltmarshes, are among the hardest hit, with an area the size of India—about 3.4 million square kilometers—lost since 1700.
This loss doesn’t just harm wildlife but also weakens our ability to fight climate change and prevent flooding.
Rivers, too, are shrinking due to water extraction and dams. Some rivers, like the Colorado River, no longer flow to the sea. What’s left of these habitats is often polluted by sewage, industrial waste, and plastics. Agricultural runoff, including pesticides, is especially harmful to freshwater wildlife. Despite these challenges, freshwater ecosystems are less studied than oceans, leaving many species without the support they need.
Dr. Topiltzin Contreras MacBeath, a co-author of the study, emphasizes the importance of including freshwater species in conservation plans. “We need more investment in monitoring and protecting these ecosystems to ensure they stay healthy for both wildlife and people,” he says.
Which animals are most at risk?
The study focused on four groups of animals that rely heavily on freshwater habitats: decapods, odonates, mollusks, and fishes.
- Decapods: This group includes crabs, shrimp, and crayfish, with about 30% of species threatened. Pollution, particularly from pesticides, poses a serious risk by harming these animals, especially during molting.
- Odonates: Dragonflies and damselflies are particularly vulnerable to habitat loss, with over half of threatened species affected by wetland destruction for farming and logging.
- Mollusks: While this group wasn’t fully analyzed in the study, previous research shows about a third of mollusk species, like freshwater snails and mussels, are at risk of extinction.
- Fishes: Pollution and habitat destruction also harm freshwater fish, affecting their development and reproduction.
Protecting freshwater species will require global cooperation and better management of water resources. Governments, scientists, and communities must work together to reduce pollution, restore habitats, and create conservation strategies.
Freshwater ecosystems may be small, but their importance to life on Earth is enormous. By taking action now, we can give these species a chance to survive and thrive.
