Endangered freshwater life
The Earth can be called the Blue Planet – because more than 70 percent of the Earth’s surface is covered by water. But of all the water on Earth, only 3% is freshwater – and two of the three percent is frozen in glaciers and ice caps. This means that only 1% of the Earth’s water is liquid freshwater. Freshwater habitats are very important to protect, both for human drinking water supply, and for preserving the Earth’s biodiversity. Despite being such a small fraction of the Earth’s surface, freshwater is home to more than 10% of all known living species on Earth – and 50% of all fish! The threats to life in freshwater are many – climate change, environmental degradation, fishing, toxins and drainage are some examples.
Freshwater is home to some of the world’s most endangered species, and to a very large proportion of endemic species – species that only live in one place. In addition to fish, species of mammals, reptiles, amphibians, birds, insects, crustaceans, plants, and many other groups are also completely dependent on freshwater habitats – both for living and finding food.
A little over two-thirds of all freshwater on Earth is in the form of ice caps and glaciers. The largest portion of freshwater is locked in the massive ice sheet of Antarctica.
Despite the limited number of freshwater environments on Earth, they account for a significant and crucial part of biodiversity. In Lake Malawi in Africa, there are approximately 1000 different species of cichlids, and many of them are facing the threat of extinction.
Photo: dguenther-CC-BY-NC-SA
Gharials are crocodile relatives that inhabit rivers in India, Nepal, and Bangladesh. They are critically endangered (CR) according to the international Red List. Environmental degradation, habitat loss, and invasive species are some of the threats facing the gharials.
Photo: Charles-J.-Sharp-CC-BY-SA
The achoque is a species of salamander that exclusively inhabits a single small lake in Mexico. It is critically endangered (CR) due to human activities negatively impacting the lake and its surrounding environment.
Photo: Claude-Humbert-CC-BY-SA
The freshwater pearl mussel inhabits various water bodies in Sweden and is endangered (EN) according to the Red List. Destruction of water habitats, acidification, and invasive species are among the reasons contributing to the species' endangered status.
Photo: Joel-Berglund-CC-BY-SA
The cardinal shrimp inhabits a single lake on the island of Sulawesi in Indonesia. It is critically endangered (CR) according to the Red List, primarily due to environmental degradation and invasive species.
Photo: DirkBlankenhaus-CC-BY-SA
The Amazon river dolphin is a freshwater dolphin species that inhabits the Amazon River and its tributaries. The species is endangered (EN) according to the Red List, primarily due to hunting, fishing, and environmental degradation.
Photo: Nortondefeis-CC-BY-SA
Almost all species of harlequin toads in the Atelopus genus are endangered, including this species, which is critically endangered. Habitat loss, environmental degradation, and fungal diseases are significant threats to these toads.
Photo: Beto_Rueda-CC-BY
The Magdalena River turtle inhabits a single river basin in Colombia. It is critically endangered (CR) according to the Red List, primarily due to habitat loss, environmental degradation, and hunting.
Photo: Daniel-Hincapie-CC-BY
The Siamese Tigerfish inhabits freshwater areas in Thailand, Cambodia, and Vietnam. The species is critically endangered (CR) according to the Red List. Threats include habitat loss and capture for the aquarium trade.
Photo: Daiju-Azuma-CC-BY
The hairy-nosed otter inhabits freshwater areas in Southeast Asia. The species is endangered (EN) according to the Red List. The threats include illegal trade, hunting, and environmental degradation.
Photo: Rigelus-CC-BY-SA
The Titicaca water frog inhabits a single lake in the Andes of South America. It is classified as Endangered (EN) on the Red List, primarily due to environmental degradation, habitat loss, and illegal capture.
Photo: Petr-Hamernik-CC-BY-SA
Madagascar’s rich freshwater
About 88 million years ago, the island of Madagascar off the coast of Africa was connected to India. However, as the continents shifted, the island became isolated, and new species could emerge without interference from the mainland. The island is perhaps best known for its lemurs, chameleons and baobab trees – but the fact is that Madagascar also has an incredible diversity of freshwater species. The combination of the island’s isolation and a very large variety of natural habitats has led to the development of a variety of freshwater species that are unique to the island. However, as with freshwater species in other parts of the world, many of Madagascar’s endemic species are highly endangered.
So far, it is not possible to breed and release individuals of the endangered species back into the wild. This is because the natural environments are so degraded or altered – that the chance of survival is too small. Therefore, conservation programmes for the endangered species are needed in other places, such as universities, public aquariums or with private individuals.
The Mangarahara Cichlid, also known as the "Red Lady," is one of the world's most endangered species. Destruction of the fish's habitats in Madagascar has led to its classification as Critically Endangered (CR) on the Red List.
Photo: H.-Zell-CC-BY-SA
The Sakaramy killifish inhabits small river systems in northern Madagascar. Once thought to be extinct in the wild, it is now classified as Endangered (EN) on the Red List. The invasive guppy, which preys on Sakaramy killifish fry, along with habitat destruction, are the main reasons for the species' threat.
Photo: Jesper-Flygare-Malmö-Museum
The Loiselle cichlid is threatened by habitat destruction and the introduction of invasive species that have outcompeted it and other native species. Today, it is classified as endangered (EN) on the Red List.
Photo: Jesper-Flygare-Malmö-Museum
The zona thrives in shaded, clear-water rainforest streams. This fish is endemic to Madagascar and is classified as endangered (EN) on the Red List. Human activities have significantly impacted its habitat. Deforestation leads to soil erosion, resulting in the muddying of waterways.
Photo: Andrzej-Otrebski-CC-BY-SA
Just like many other cichlids in Madagascar, this species is critically endangered (CR) according to the Red List. The pinstripe menarambo was thought to be extinct in the wild, but it was rediscovered in a river in Madagascar. Overfishing and environmental issues are threatening its habitat, and introduced species are also taking over the cichlid's environment.
Photo: Johanna-Rylander-Malmö-Museum
It's not only fish species that depend on the rich freshwater environments in Madagascar. Many birds, such as the Madagascar grebe, are endemic (unique) to Madagascar. This bird is endangered (EN) according to the Red List due to environmental degradation, habitat loss, and invasive species.
Photo: Alextelford-CC-BY-SA
The Golden Mantella is a small frog that inhabits areas near wetlands and flowing water in a very limited part of Madagascar. The species is endangered (EN) according to the Red List, mainly due to the destruction of the frog's habitat and invasive species.
Photo: Frank-Vassen-CC-BY
Astacoides is a genus of crayfish that is endemic to Madagascar. The majority of species in this genus are vulnerable (VU) according to the Red List. The main reasons for their vulnerability are typically habitat loss, invasive species, and fishing.
Photo: Axel-Straus-CC-BY-SA
What can I do?
-Get involved in organisations that fight for the conservation of freshwater environments – such as the World Wide Fund for Nature (WWF) or the Swedish Society for Nature Conservation.
-Get involved in politics or remind your politicians of the importance of working for biodiversity.
-Reduce your consumption of gadgets, clothes and food that require a lot of water in production. Shop second-hand, locally produced and seasonal.