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The salmon run

Leaping salmon by Rob Jordan/2020VISION

Marvelling at a salmon leaping over an obstacle in a river is one thing but contemplating the journey that preceded the leap is quite another.

We're in the peak of the salmon run when most adult Atlantic salmon return from the sea to spawn in the upper reaches of rivers and if you head to Worcestershire's Severn or Teme you may be lucky enough to watch the last leg of this journey. Having tried this before, I've discovered that patience comes in very handy but if you think about the extraordinary life of these fish, you’ll realise that catching sight of a leaping salmon is worth waiting for. 

The fish that are currently swimming (or 'running') up the Severn were born here two to five years ago. Many headed out to sea just last year and they’ve been feeding voraciously on sand eels and herring ever since. Most salmon return in autumn to the river in which they were born – they head upstream until the female finds a suitable fast-flowing, clean section of river with a gravelly bed.  She uses her tail to create a depression and then lays her eggs; the accompanying male fertilises them and they cover up the eggs.  The vast majority of salmon then die but a few females will head back to sea and return again to spawn next year.

As with most things, it’s not quite that simple.  For us, it’s about names.  For salmon, it’s about access.

Salmon by Linda Pitkin/2020VISION

Atlantic salmon by Linda Pitkin/2020VISION

Salmon aren’t only known as salmon.  When they’re very small they’re known, as with many fish, as ‘fry’.  As they grow, they’re known as ‘parr’; at this stage they develop blotches and bands along their flanks.  After about two years, the spots disappear as a silvery sheen takes over and the back of the fish turns greeny-brown – the salmon now become known as ‘smolt’ and it’s at this stage that they head to sea.  Once they’re ready to return to the river, they’re known as a ‘grilse’ and once they’ve spawned they’re known as ‘kelts’. 

It doesn't end there! Some salmon return to our River Severn in the spring. These are larger fishes that have spent two to four years out at sea and are known as 'springers'.

Whilst we’re battling with names, the fish are battling with barriers.  We’ve added weirs, locks and other barriers to help our navigation but these haven't helped the fish’s migratory routes.  Our colleagues at the Unlocking the Severn project, however, are improving fish passage up the Severn by installing fish passes and undertaking work on some of the weirs. They even have a viewing gallery at the fish pass in Worcester - you can book tours to see what's on its way up the river.

If you're not able to get to Worcester's fish pass, keep an eye on where salmon are leaping by following the hashtag #spawningwatch on Twitter.

You can discover more about salmon in this short video from my colleague Ion...

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