Freshwater Biodiversity

Freshwater ecosystems cover less than 1% of Earth's surface, yet are home to at least 10% of Earth's species.

Freshwater habitats are incredibly diverse, with more than 400 large-scale ecoregions and thousands of rivers, lakes, and wetlands.

Freshwaters are also hotspots for biodiversity. They are home to at least 140,000 specialist freshwater species!

Due to their isolation and the specific challenges of living in a freshwater environment, levels of endemism are also extremely high. Over half of freshwater fish species are found in just one single ecoregion.

@WWF

Specialist freshwater species account for around one-third of all vertebrate species and 51% of all fish species

That accounts for almost 18,000 freshwater fish species!

Freshwater habitats also have a rich fauna of invertebrates

And over 80% of the world’s turtle and tortoise are freshwater species.

WHAT IS A FRESHWATER SPECIES?

Freshwater specialist species complete all or part of their life cycle in fresh or brackish water ecosystems and have physiological and behavioural adaptions to the freshwater environment.

Freshwater associated species have a strong association with freshwater ecosystems, for example, for food or habitat.

Freshwater Biodiversity at risk

Globally, wetlands have declined three times faster than forests, and freshwater vertebrate populations have declined by 84% since 1970 according to our Living Planet Report 2020; twice the rate of decline of biodiversity in terrestrial or marine biomes.

One third of all freshwater species are at threat of extinction including: 61% of freshwater turtles; 40% of amphibians; 30% freshwater fishes; and 43% of freshwater mammals. One quarter of Critically Endangered species are freshwater species.

The main causes of biodiversity loss are flow alteration, pollution, habitat degradation and loss, overexploitation of species, and invasive non-native species.

What's our impact on freshwater species