Returning Salmon

[Gillies]

Following Graham X’s thread about the dead Salmon he found on the beach, I was wondering about the latter stages in life of the Atlantic salmon, just how they return to the sea after spawning, and the biological stages than go on within it.

 

Can anyone shed any light on the subject for me?

 

Is it true that when the Salmon enters the fresh water that its stomach slowly begins to dissolve? So leaving it not been able to feed in the fresh water … hence it having to live of it’s own body fat? I spoke to someone who once sat dropping worms into a small river in mid-summer and watched the Salmon take them into their mouth and then spit them back out, from what he could see the Salmon would take it down deep to the back of its throat and then squeeze the juices out of the worms, then spit its body back out.

 

If this is true and the stomach does dissolve, do kelt fish that survive spawning and return to sea develop new stomachs?

 

Is it just female fish that if it’s lucky can return to the sea alive?

 

When I fish for Brown Trout in early April time up here on the Isle of Lewis on a large loch called Langavat, it is full of Kelts waiting “I think” to return to sea down the Grimesta system … their bodies seem to be changing from the dark reds, browns of the Autumn/Winter fish back to the Silver of a fresh fish … although they have no depth to their bodies at all … and still have the mushy gills. It may sound daft, but they look like a cross between a Salmon and an Eel they are so streamlined and thin.

 

Any information on the latter stages off an Atlantic Salmons life when it enters the fresh water would be great.

 

Gillies

[Adz]

The stomach doesn't dissolve, but it does atrophy (shrink considerably) - whether this is to prevent them from eating or because they don't eat I don't know. Certainly there are significant biological and biochemical changes in the salmon to allow it to survive in both fresh and saline environments - possibly this is where the feeding changes appear?

 

It's not only female fish that can return, cock fish can too, but from what I've heard it's significantly less likely to encounter a returning cock fish than a hen. This could be because cock fish service more than one redd whereas females spawn only the once before resting/returning.

 

Apparently, from information I've seen at a glance for the Spey, only some 2% of salmon returning, that were caught, were repeat spawners - although a much greater proportion had spend multiple winters at sea but were making their first spawning run.

 

Kelts are much more vulnerable to predation than fresh running fish too, so this is most likely where the majority of mortality occurs.

 

Please note, I'm not an authority, just a layman, so some of the above may well be incorrect - but it should give you an idea.

 

Cheers,