Atlantic Salmon, Sea Trout and European Eels

(The following information has been taken from the website of the Ribble Rivers Trust)

Atlantic Salmon

One of the best places to see leaping Salmon is at Stainforth Force, a few miles upstream from Settle

The Atlantic Salmon is one of the largest fish to be found in the Ribble Catchment. They can weigh from 3lbs up to around 40lbs. The Salmon enter the river at various times of the year and “run” up the river to the small becks and streams to lay their Eggs (Spawn).

In the winter they gather in pairs in areas of good clean water and gravel. The female fish digs a hollow (also known as a 'redd'!) in the gravel using her tail. She lays her eggs in the hollow and the male then sheds his milt to fertilise them.

The eggs hatch as Alevins in the spring and remain in the gravel until they have absorbed their yolk sack. At this point, they leave the cover of gravel and start to feed in open water when they become known as Fry. The Fry become Parr once they have spent their first winter in the river.

In the spring after a second winter (or after up to 4 winters), the Parr migrate to the ocean (sometimes as far away as Canada) where they feed heavily on the rich food.

After one winter some will return to the river as Grilse whilst others remain in the ocean for up to 4 winters before returning as Salmon to start the cycle again.

The Salmon almost always return to the stream where they hatched as an Alevin.

Salmon can be seen leaping waterfalls and weirs and sometimes leaping out of the water in a pool for no obvious reason!

After spawning in the winter the Salmon are called Kelts (around 80% of Kelts die!). The carcasses of the dead Kelts provide important food for invertebrates (and other animals along the river banks), which in turn provide food for the Salmon Fry.

Sea Trout

Sea Trout are very similar to Salmon, and you may have to look closely to tell the difference. They can grow up to 21lbs but this is very rare.

As with Salmon, the Sea Trout lay their Eggs in gravel, but generally smaller gravel than the Salmon and also in smaller becks.

The Eggs hatch, becoming Alevins and Parr and head to the sea in the spring.

Some Sea Trout will return before the first winter, whereas others will remain in the ocean for longer periods.

The Sea Trout don’t travel as far in the ocean as Salmon, sometimes remaining within a few miles of the estuary of the river of their origin.

Sea Trout tend to run the rivers at night and are more elusive than the Salmon during the day. However, at night you can see them trying to wriggle through very shallow water often with their backs out of the water.

Many fewer Sea Trout die after spawning and it is not uncommon for them to spawn several times.

European Eel

In 2014, an Eel Ladder was installed at Settle weir to make it easier for elvers to negotiate the weir.
The Eel Ladder can be seen on the opposite bank to Settle Hydro.

The European Eel is a long slender snake-like fish with two pectoral fins and a joined dorsal and tail fin. It has a dark grey-blue upper body and a lighter grey white underbelly. It feeds mainly on other fish, hunting at night.

It has a migratory journey as part of its reproductive cycle which is almost in reverse to that of the Salmon.

The juvenile Eels or Elver enter our rivers and streams and travel upstream, sometimes over land and out of water (Eels are capable of breathing through their skin and as such can withstand low oxygen conditions).

In Freshwater, they grow quickly and often can reach 90cm in length.

They reach sexual maturity between 5 and 10 years old, at which point they migrate downstream to the ocean, where they head to the Sargasso Sea to breed.

The juveniles use the Gulf Stream to travel back to Europe where they enter our river and streams.

Ribble Rivers Trust

River Ribble Fact Sheet

Atlantic Salmon Trust