Salmon, Snakes and Ladders

We are restoring the River Ecclesbourne to allow salmon (and other species) to return to their natural spawning grounds, through dam removal and community engagement. Please read about our successes and further ambition to see how you can help and get involved.

The River Ecclesbourne, a major tributary of the Derbyshire Derwent, in England, starts life above the town of Wirksworth, flowing for 16 km in parallel with the Wirksworth road to Duffield, entering the River Derwent just outside the town.

In total, the River Ecclesbourne catchment drains an area of 60 km2. Including the main stem and tributaries the Ecclesbourne has 28 km of rivers and streams.

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In August 2017 the Environment Agency caught four salmon parr from a 100-m stretch of the River at Duffield; this was the first time salmon had been recorded in the river for hundreds of years. Then the following month, the first adult salmon was caught from the river. The fish was captured by Peter Cripps of Derby, fly fishing the river at Duffield. The return of the ‘king of the river’ was such a revelation and triumph, it received local and national press coverage.

The return of salmon is directly linked to fish passes built through weirs on the main River Derwent in 2013, which allowed salmon to return to the Derwent and in turn, the River Ecclesbourne. In fact, the highest number of salmon redds (spawning ‘nests’ on the riverbed) in the River Derwent are directly below the confluence with the Ecclesbourne; the drone footage below shows 100+ salmon redds (the light patches of gravel).

Salmon are anadromous, meaning they migrate from the sea to spawn in freshwater. Salmon can spend between 1-4 years feeding at sea, reaching 9-14 kg in weight and lengths of 100-110 cm (the equivalent to a 4-6 year old child).

Some salmon only spend one winter at sea and these are known as grilse. These fish, once at sea, typically don't venture beyond the Faroe Islands or Norwegian sea.

Other adult salmon spend between 2 and 4 years at sea, these are known as multi-sea-winter salmon; these fish can travel as far as Canada and Greenland.

 Learn more. 

Adult salmon don't feed once they enter rivers, instead they can live on their fat stores and body tissue for up to a year, before heading to the same clean, gravel-bedded headwaters where they originally hatched. Adult salmon tend to remain dormant for much of their time in rivers, waiting for the right season and flow conditions to make their journey to the spawning grounds.

Once an adult salmon has returned to freshwater, it will join others and spawn between November and December. Salmon choose well flushed, open gravels in cool and clean rivers, where they create nests in the gravel (redds) and lay their eggs. Once hatched, juvenile salmon (known as parr) will live in the rivers for 1-2 years before making their journey out to sea. We know from scale ageing (like counting rings of a tree) that salmon parr in the Derwent are fast growing and migrate at 1 year old, having already reached a length of over 10cm.

The map below demonstrates the extraordinary journey the salmon in the River Ecclesbourne, in Duffield, are making (over 2000 km!).

A combination of behavioural and genetic factors trigger their urge to migrate back to the rivers. Though the scent of their natal river is powerful, it is thought as many as 1 in 10 salmon stray into a different river from the one where they were born. This straying behaviour ensures the spread of diversity and resilience amongst different populations; you could also call some of these "stray salmon" recolonisers... which where today’s Ecclesbourne salmon have come from.

Larger ‘spring’ salmon (weighing 5 - 10kg or more) tend to be those that have spent multiple winters at sea, often using their extra strength to forge their way upstream in more tempestuous flows and over large barriers before river levels lower as the summer progresses. Later in the year, the run is dominated by smaller, single sea-winter fish (less than 4kg). These smaller grilse, being later running, may not make it as far up a river.

Since 2018, the Environment Agency has been recording the locations of salmon redds in the River Ecclesbourne to get a better understanding of the population. The distribution of salmon redds in the Ecclesbourne is mapped below.

It is evident that Snake Lane weir is having a massive negative impact on Atlantic salmon by preventing them from progressing further upstream. Within the 500 m of the River Ecclesbourne already accessible to salmon, the number of redds has averaged 8-12 per year since 2018. If we extrapolate the number of redds for the entire River Ecclesbourne, we would expect the river to support over 200 redds. The map shows that there are only two barriers to salmon (and other fish species) along the River Ecclesbourne.

It’s not just salmon that are impacted by these barriers. Each autumn brown trout attempt, and fail, to pass Snake Lane Weir during their spawning migration. This opportunistic video, shows the size and impassibility of the barrier in comparison to the brown trout.

Downstream of Snake Lane, fish surveys over the last 20 years have caught 16 species, whilst above Snake Lane weir only 8 have been recorded - including two species that were introduced for angling (grayling and rainbow trout).

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The Ecclesbourne Restoration Project isn't just about reconnecting salmon to their former spawning grounds or creating climate resilient nature ... it is also about people, communities and the future. We are reconnecting and engaging people with their river. Each day, the residents of Duffield, including children from both the Primary and High Schools, walk past Snake Lane unaware they are passing salmon which have travelled over 2000 km to their home town. That is why we are working with schools in the Ecclesbourne catchment delivering assemblies, talks, tackling Invasive Non-native Species and other activities to engage and educate.

We want people to touch, feel and treasure their river. We want to establish citizen science projects, create pieces of artwork to engage and encourage more people to explore - have adventures along the river and enjoy the Ecclesbourne Way ... travelling the same route as the salmon.

But mostly we want people to take on the ownership of their river, becoming protectors and champions to safeguard it for future generations.

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We have secured the funding for the construction of the Salmon Ladder at Snake Lane Weir and the construction of the bypass channel at Postern Mill, but donations are welcome for community and engagement projects. If you are able to help then please contact us.

Likewise, if you would like to get involved in any of the community projects please contact us.

Please enjoy our short film produced by Wildlife Photographer & Presenter -  Jack Perks .