Blueprint launched to save 1,000 of the world’s most threatened fishes

A new project to kickstart conservation for some of the world’s rarest fishes is making a splash.

Despite covering just 1% of the Earth’s surface, freshwater habitats host over half of all fish species. Unfortunately, decades of habitat destruction, pollution, water extraction and dam construction mean this precious biodiversity is under threat, with over 80 species going extinct over the past century.

The 1,000 Fishes Blueprint, launched by the Shoal partnership, aims to push back against this concerning trend. It’s hoping to work with everyone, from governments to local people, to put a variety of species on the road to recovery by 2035.

Shoal’s Executive Director, Mike Baltzer, said that the blueprint “shows the level of ambition and determination we need to turn back the tide on the freshwater biodiversity crisis.”

“We need to halt extinctions and recover populations of the world’s most threatened freshwater fish,” Michael says. “It is collaborative to its core and puts local communities at the forefront of impactful conservation action. It is urgent that we now push on and mobilise the conservation actions outlined by the blueprint – our planet’s freshwaters depend on them.”

Freshwater under threat

As much as 70% of the planet’s surface is covered in water, but only a fraction of it is freshwater.

Nonetheless, the world’s lakes, rivers and streams support all manner of life on our planet. And yet, despite its importance, the animals which live in it tend to be overlooked as Dr Rupert Collins, the Natural History Museum’s Senior Curator of Fishes, explains.

“Freshwater biodiversity is so important for us and our planet, with many species of fish living in just one small part of a river or lake and nowhere else on Earth,” Rupert says. “However, compared to charismatic mammals or sea life, its conservation is extremely overlooked.”

“This is particularly problematic, as any impacts on one part of a freshwater ecosystem can spread throughout it. Pollution on land, for instance, tends to stay relatively localised, but pollution in a river will have knock-on effects for everything living further downstream.”

The main threat affecting freshwater fish is habitat destruction, which impacts almost 70% of all species. It’s a particular issue in tropical regions, where the removal of rainforests, wetlands and peat swamps for agriculture is driving the loss of rare species.

Pollution follows as a close second, with the rivers of the world choked with sewage, rubbish and chemicals.

“In every country in the world, people treat rivers as waste disposal,” Rupert says. “They throw their rubbish and effluents in them, and it’s carried away. But while it’s no longer a problem for them, it’s a real issue for the river. It can have so many negative effects, reducing oxygen, generating algal blooms and creating microplastics.”

Together with other threats such as water extraction, dam construction and invasive species, these issues are causing freshwater diversity to decline twice as fast as on land or in the sea.

A blueprint for recovery

This is where Shoal’s blueprint comes in. It wants 1,000 species of fish from over 2,300 priority species to receive urgent conservation action by 2035. Though this seem like a lot to do in just 11 years, the blueprint believes its goals are achievable.

Take the Devils Hole pupfish, for instance. Found in just one flooded cavern in Nevada, USA, the fish lives in what is thought to be the smallest habitat of any vertebrate species on Earth. Rising levels of groundwater extraction in the southern USA threatened its survival, with its wild population dropping to just 35 in 2013.

But following efforts to reduce water demand in the region the fish’s population has been growing, reaching 191 in April 2024. A full-size replica of the top portion of Devils Hole was also constructed, and now hosts a small captive population as a backup.

In fact, over a quarter of the fishes in the blueprint are already receiving enough conservation attention to turn their declines around. The challenge now is to focus on the remaining 712 which are not yet receiving the attention they need to survive.

One such species is Typhleotris pauliani, a Critically Endangered cavefish found in southwest Madagascar. Like many of the island’s species, it is a distinct branch on the tree of life with its closest living relative found thousands of miles away in Australia.

Unfortunately, its subterranean lifestyle means very little is known about it, so much so that its population hasn’t even been estimated for the IUCN Red List. But without urgent conservation action there are concerns that disturbances from tourism and the guano industry could push the fish towards extinction.

Shoal’s blueprint aims to avoid the extinction of at-risk fishes like T. pauliani by putting together specific action plans for each species, uniting governments, local initiatives, and industry partners for conservation.

Extinct species resurfacing

As well as bringing back species from the brink, the blueprint wants to go one step further – bringing back fishes presumed dead. While resurrection isn’t on the cards, recent discoveries have shown that it’s always worth checking whether a species really is extinct.

“The rediscovery of extremely rare – and sometimes extinct – fish is more common than you might think,” Rupert says. “Recently, the leopard barbel and the Diyarbakir loach were rediscovered in Turkey, decades after they were thought to have vanished.”

“Sometimes, it’s simply a matter of looking in the wrong place, or having trouble finding the fish in dark, murky waters. New technologies, such as environmental DNA (eDNA) can help with this.”

If any of the very rare or extinct fish are rediscovered, then it will be vital to start protecting them as quickly as possible. The rapid action taken to protect the Mangarahara cichlid after its 2013 rediscovery, for example, was credited with ensuring the species’ future survival.

It’s hoped that over the next 11 years there’ll be plenty more success stories for the world’s freshwater fishes. If all goes according to plan, then the world’s rivers, lakes and streams will be much cleaner, healthier and fishier than they are today.