Lakes That Are Home to Endangered Species

Lakes don’t get much attention in the global conversation about wildlife conservation. And it’s not difficult to see why: lakes are all around us, and they just don’t seem all that exotic. Most people don’t have to trek across the globe to encounter lake biodiversity. They don’t have the flashy, charismatic species of the tropical rainforest or the coral reef. And their importance to the global environment is pretty easy to miss.

When it comes down to it, lakes aren’t what many people think of when they imagine saving wildlife. But 10% of all known species on Earth reside in or rely upon freshwater lakes. They make up just 1% of Earth’s surface, but lakes contain almost as many known fish species as all of the world’s oceans combined. A third of all vertebrates call lakes home. And a growing number of those species are experiencing rapid declines as human activities like pollution, habitat degradation, and damming threaten fragile, one-of-a-kind lake ecosystems.

Lakes don’t command the attention of some of Earth’s other endangered ecosystems. But that’s not for lack of merit. These six lakes - one on every continent except Antarctica - are all home to endangered species you may not have heard of.

Africa: Lake Malawi

Africa’s tropical lakes are some of the most biodiverse habitats on Earth, and the third-largest, Lake Malawi, is especially hot. It’s located in a rift valley zone between Malawi, Mozambique, and Tanzania, and its species richness is unmatched even in a region known for its biodiversity. In fact, it’s home to the greatest number of fish species of any lake — over 800, according to estimates — and many of them are found nowhere else. What’s more, a recent survey found 9% of the 458 confirmed and assessed species in the lake are in imminent danger of extinction.

It’s no surprise that millions of people who live in the surrounding region rely on Lake Malawi’s fish stocks for food. Thus, overfishing is a major cause of Lake Malawi’s declining fish stocks. One notable example: the four species of Chambo are some of the most iconic fish in Lake Malawi, a national symbol, and three of them are critically endangered, a victim of their own popularity as a food fish. As Malawi’s population grows, the need for increased food supplies will likely continue to strain the lake’s fish stocks if alternatives aren’t found.

Also endangered are the kampango catfish, a large species found nowhere else, and hundreds of species of small tropical fish called cichlids. Small, brightly-colored, and relatively easy to keep, cichlids are extremely popular in the aquarium hobby industry; thus, they, too, are often victims of their own popularity. Other threats to Lake Malawi’s biodiversity include agricultural runoff, erosion, and falling water levels due to decreased rainfall. Restoring degraded ecosystems around the lake, finding sustainable food solutions, and keeping tabs on the aquarium trade will all be critical for the well-being of Lake Malawi’s many endangered fish species.

Asia: Lake Poyang

There are a handful of lakes in China known for their endemic species, and many of those are endangered. But it’s Lake Poyang, the country’s largest freshwater lake, that often gets top billing in discussions of China’s endangered lake species. And that’s all thanks to one charismatic species found almost nowhere else.

Of course, one species alone isn’t the whole reason Lake Poyang is included on this list. In the winter months, it’s also a hub for rare migratory birds, and around 90% of all critically endangered Siberian Cranes and over 80% of Oriental white storks stop by the lake during their seasonal migrations.

But the real story here is that of the Yangtze finless porpoise. With an estimated population of just under 1300 individuals in 2023, it’s one of the world’s most endangered cetaceans, and Lake Poyang is home to one of the world’s last stable populations. Because it drains into the Yangtze, China’s longest river, Lake Poyang faces significant ecological threats due to human activity. Shipping traffic, pollution, sand mining, and the building of the Three Gorges Dam have all adversely impacted the lake and its native species.

Australia: Coorong and Lower Lakes

Part of a complex of lakes that makes up Australia’s most ecologically important wetland, the Murray-Darling Basin, Coorong and Lower Lakes host several of the continent’s most threatened species. Like many of the world’s most ecologically significant lakes, this region is a migratory bird hotspot, particularly known for the endangered Fairy Tern and the Orange-Bellied Parrot, one of the very few species of parrots that are known to migrate. But the animals that call the lake itself home are under threat, too.

Amphibians are frequently among the most threatened lake-dwellers. In Australia, it’s the endangered Southern Bell Frog that’s paid the price of declining water levels in the Coorong and Lower Lakes. Invasive species that prey on the frogs have also greatly impacted their numbers. A small fish called the Murray hardyhead is similarly impacted by the introduction of invasive species, and natural disasters or environmental fluctuations like drought can be extremely destructive to its numbers.

Plants, too, can be impacted by the same environmental stressors that harm endangered species in the Murray-Darling Basin. The metallic sun-orchid is one of the emblematic species of the lakes, growing on the banks of the Coorong and Lower Lakes. Still, grazing animals and invasive weeds have made it difficult for the orchid to maintain its population.

Europe: Caspian Sea

While not entirely located in Europe, the Caspian Sea straddles the European border, and it’s home to one of the most charismatic endangered species in any worldwide lake. Fish, amphibians, and even plants endemic to a single lake are often under threat — but it’s pretty rare to find a lake-endemic mammal species. The Caspian Sea has one of its own.

As the world’s largest saltwater or brackish (mixed fresh and saltwater) lake, the Caspian Sea is able to support species that freshwater lakes can’t. And with its small, furry body and large eyes, the Caspian seal is easily the most winsome of those species. It’s the only marine mammal residing in the Caspian Sea, cut off from its marine cousins by the landlocked lake it calls home. It’s found nowhere else — and its numbers have fallen by 90% from the 20th-century population of a million individuals.

It’s not entirely clear how Caspian seals came to be endemic to the Caspian Sea, or even what marine seals they’re most closely related to. What’s clearer is why the species has seen such a huge decline in its numbers. For most of the 20th century, the seal was classified as a “harvested species” by four of the five countries that border the lake. This encouraged large-scale hunting of Caspian seals for their fur and blubber.

Although the Caspian seal is now only hunted in small numbers from the Russian side of the lake, other threats to the species are present. Pollution, Canine Distemper Virus, the shrinkage of the Caspian Sea, and fishermen's intentional or accidental killing of seals all hinder efforts to help the Caspian seal’s numbers rebound.

North America: Great Lakes

The five Great Lakes located on the border between the United States and Canada aren’t exactly remote: roughly 10% of the U.S. population and 30% of the Canadian population live on their shores. But that doesn’t mean that the region isn’t home to a wide range of endangered species — in fact, it’s one of the major reasons that it is.

Though there are many species in decline in the Great Lakes, one of particular note is the imposing Lake Sturgeon. They can measure up to seven feet long, and like many depleted fish species, it was once extremely abundant. But by the turn of the 20th century, the demand for the fish’s flesh for smoking and roe for caviar made sure that it wouldn’t remain so, and the fish were too rare to support fisheries over a hundred years ago. Sadly, this venerable Great Lakes resident has not rebounded significantly since then.

But overfishing is not the only factor negatively impacting Great Lakes species. Currently, the region is dealing with a huge influx of invasive species, including intruders like the zebra mussel and lamprey, which have made national news for the destruction they cause to local animal populations. The urbanization of the Great Lakes area has additionally brought on problems with pollution and habitat degradation.

South America: Lake Titicaca

Lake Titicaca is a lake of superlatives: the highest navigable lake on Earth, the second-largest in South America, and one of the largest lakes in the world with no outlet — so it’s no surprise that it’s also home to some exceedingly rare species. And the poster child for Lake Titicaca’s conservation is a rather unlikely one: the world’s largest fully aquatic frog.

The Titicaca water frog isn’t the most photogenic ambassador. Its loose skin has earned it the immensely unfortunate nickname of ‘Titicaca scrotum frog.” But as one of the largest frogs to spend its entire lifespan underwater, it’s ecologically unique, and you won’t find it in any other lake. A plethora of threats to Lake Titicaca have put the frog in danger.

In a lake with no outlet, pollution has nowhere to go, and contamination of the water supply is hugely detrimental to a frog that lives entirely underwater. Introduced fish species prey on the frog, and the frogs are captured for sale as everything from pets to food and traditional aphrodisiacs. On top of that, mass die-offs of unknown cause have precipitously dropped the frog’s numbers since the early 2000s.

Because the Titicaca water frog is such an iconic emblem of the ecosystem it calls home, it’s become a canary in a coal mine for the health of the lake overall. Efforts to save the Titicaca water frog entail nothing less than the restoration of the whole ecosystem. Conservation efforts can’t focus on frog breeding or population recovery: they must holistically treat the health of Lake Titicaca itself.

Unique Species In These Scenic Lakes

On every continent and in countless countries, lakes are home to some of the most threatened and unsung species you’ll find anywhere. And what they lack in flashiness, they almost always make up for in ecological significance. Lakes provide vital freshwater and food resources; host species found nowhere else; and perform water-purification processes vital to the health of surrounding ecosystems. And the endangered species that call these lakes home are eloquent ambassadors for the importance of preserving them in the face of numerous human threats.