Lost Salmon

[gavintc]

I am confused by this article. I was always under the impression that salmon were amazing fish in that they leave the river of birth, swim thousands of miles and then remarkably return to the same river. If that is the case how do you get salmon to 'reintroduce' themselves to a river unless they are lost or the premise about these amazing fish and their navigation systems is complete bunkum.

http://news.bbc.co.uk/1/hi/world/europe/8196801.stm

 

[Aperitif]

I use salmon on my bikes - they stop a treat!

 

[scots_lass]

Maybe some salmon just fancied a change of Seine!

 

[Arch]

I am confused by this article. I was always under the impression that salmon were amazing fish in that they leave the river of birth, swim thousands of miles and then remarkably return to the same river. If that is the case how do you get salmon to 'reintroduce' themselves to a river unless they are lost or the premise about these amazing fish and their navigation systems is complete bunkum.

http://news.bbc.co.uk/1/hi/world/europe/8196801.stm

I would imagine a few possibilities.

a) they introduced fry, but haven't said so
there will possibly always be some fish who stray - the equivalent of the mutant genes that drive evolution, and they will have 'found' the Seine and recolonised it. In the same way that migrant birds get blown here, only if enough arrive, they can breed.
c) there have been fish swimming about trying to return to the Seine, but being driven back by pollution. I don't know what the time scale is between leaving the river and returning to spawn, so I don't know if this is possible, given the time since they were last seen. Fish might have been not spawning year after year until the river was ok for them. I do know that not all salmon die after spawning, but I can't remember whether it's the Atlantic or Pacific that does - possibly they've been making do with other rivers.

 

[Arch]

I use salmon on my bikes - they stop a treat!

Don't you mean "trout"...

 

[tandemman]

The pacific ones die, the Atlantic ones live to return again, many times if uncaught, it's the reason for putting kelts back, apart from them being inedible

 

[Globalti]

There's only one place for a salmon:

 

[trustysteed]

maybe they just took the wrong roe-d?