At the tail end of last year at the COP28 UN climate conference, the first full assessment of the world’s freshwater fish species was released by the IUCN in their update to the Red List of Threatened Species. This showed what many might have feared - that 25 per cent of freshwater fish are at risk of extinction.

The report revealed the biggest threat to freshwater fish is pollution. But there is a compound effect of dams and water extraction, both of which can make it difficult for fish to travel up and downstream, as well as invasive species, disease and overfishing too. Climate change and the changing seasons are also causing problems for threatened freshwater fish, as winter storms can damage habitat, summer water levels are decreasing and sea levels are rising causing seawater to move further up rivers.

One species in particular danger is the majestic Atlantic salmon. With its shimmering silver scales, dark spots and distinctive hooked lower jaw that develops in mature males. One of the largest fish found in UK freshwaters, it has an average lifespan of 13 years and reaches 1.2 to 1.5 metres in length. You can see why it is named across the world as the ‘King of fish’!

While the fish spends most of its life at sea, in autumn mature Atlantic salmon return to their ancestral spawning grounds in the rivers where they hatched. From September to November key rivers in Scotland, Wales and north and south-west England are home to Britain's famous Atlantic salmon run.

These fish are much admired for their determination in swimming upstream against the deluge of white waters. They must leap huge waterfalls, weirs and other barriers upstream to reach their spawning gravels. Sometimes referred to as ‘the leaper’ they have been known to jump an incredible twelve feet into the air.

But now the King of Fish’s watery journey migrating between marine and freshwater habitats faces the greatest threat. As the blue veins of the planet are facing multiple pressures from climate change, toxic pollution, human disturbance and extreme weather events, the Atlantic salmon and other freshwater fish are in trouble.

The main UK population of Atlantic salmon have been reclassified as endangered – meaning they are threatened with extinction, while global Atlantic salmon populations have been reclassified as near threatened. And so the UK is set to lose this iconic species first and before anywhere else on the planet, unless urgent action is taken. 

Atlantic salmon are one of a handful of species, called keystone species, which are vital to the habitats in which they live. As a predator, as prey, and through their actions to alter river habitats to suit their needs, such as by creating areas in which to spawn, they have a huge influence on the health of a river system and its residents.  So we must enforce the law and regulations that protect habitats and rivers from toxic pollution; The nutrient pollution from sewage spills, agricultural run off, pesticides and chemicals need preventing at source before they reach our rivers.

Thanks to campaigning by The Wildlife Trusts and others, the UK Government was recently blocked from weakening water protections, where nutrients are already harming sensitive rivers and coasts.

However, there are other factors that threaten this incredible species, such as the impact of sea lice and interbreeding with escaped farmed salmon. While multiple in-stream structures such as weirs, prevent salmon, brown trout and other fish migrating back to their upstream spawning grounds. Many of our headwater streams are cut off, structures disrupt river flows, fish movement and their ability to breed and reproduce.

Help stop wild Atlantic Salmon, one of our most iconic and inspiring animals, from becoming extinct from our watery habitats across the UK. Get involved with local catchment partnerships, water quality monitoring, volunteer with local conservation bodies or make your voice heard on water quality issues.

Find out more about protecting our rivers