salmon died but the sea trout lived through it.

[biglongdarren]

a few weeks ago the stream that supplies our local fish hatchery had a very heavy flood run down it,the flood was that big dirty and muddy that it killed nearly all the salmon in the tanks,but the sea trout living in the same tanks survived,
i never would have though that the sea trout would have been the tougher of the two.
Darren

 

[jenkinsbrynmair]

Maybe it's because sea trout are no different genetically to brown trout - used to heavy spate rivers and over the years hardy to pollution and so on. between the mid 19th and 20th centuries Our local river had on its banks An iron works,three sheet metal works, two tinplate works, a chemical works and in excess of thirty coal mines spewing their filth into it in the 1920's the river ran yellow, my grandfather would occasionally be late for school as he used to stop for a swim on his way and gave his excuse that his father was seriously ill (which he was) but the lie was proven because his skin was a lovely shade of yellow. However the point of the story is the brown trout survived all of that and we still have a healthy stock of brownies and the river is renowned for its sea trout. (we now have excellent salmon runs as well)

 

[victor meldrew]

Maybe it's because sea trout are no different genetically to brown trout - used to heavy spate rivers and over the years hardy to pollution and so on. between the mid 19th and 20th centuries Our local river had on its banks An iron works,three sheet metal works, two tinplate works, a chemical works and in excess of thirty coal mines spewing their filth into it in the 1920's the river ran yellow, my grandfather would occasionally be late for school as he used to stop for a swim on his way and gave his excuse that his father was seriously ill (which he was) but the lie was proven because his skin was a lovely shade of yellow. However the point of the story is the brown trout survived all of that and we still have a healthy stock of brownies and the river is renowned for its sea trout. (we now have excellent salmon runs as well)

I'll bet Dad was constipated absorbing all that iron through his skin!
VM

 

[drstitson]

when grandpa was an apprentice chemist on the Isle of Dogs many moons ago he and his mate would go down to the river with their packed lunches and while away lunchtimes by throwing fist size lumps of sodium etc into the water.

I often thought that they may have been singlehandedly responsible for the absence of salmon etc from the Thames until after his retirement!!!!

 

[jenkinsbrynmair]

I'll bet Dad was constipated absorbing all that iron through his skin!
VM

it was only in the last few years of his life that I realised Granddad had no top set of teeth he used to eat steak and crack nuts with just the bare gums (but then again his cure for a headache was to punch himself to get a nosebleed to relieve pressure!) So there must have been something beneficial in the water!!

 

[jenkinsbrynmair]

or he was just mad as a bag of snakes in a frying pan!!

 

[RoofTops]

I suspect the salmon came from farmed stock which is generally lower in genetic diversity than wild salmon and is more prone to disease. The sea trout may also have been from farmed stock, but I suspect they were closer to their wild cousins and may have actually been bred from captured wild fish.

I would also guess it was not the muddy water which killed them but escaped sewage or something like that. All wild salmon start in fresh water streams just like sea trout, so they get exposed to the same hazards and should in the wild be able to cope with natural disasters.

 

[biglongdarren]

no sewage involved,the water flowing through the hatchery comes from high up in the mountains,the hatchery itself is very high up into the mountains so the water is as pure as it can be really.

 

[biglongdarren]

i think most of the dead salmon gills were all silted up,while the sea trout were able to keep themselves clear.

 

[biglongdarren]

one of the fish they had for the hatchery last year...http://www.kilkeelanglingclub.btck.co.uk/Gallery/Fish

 

[jenkinsbrynmair]

i think most of the dead salmon gills were all silted up,while the sea trout were able to keep themselves clear.

I believe that salmon (especially alevins are more succeptible to suspended solids(siltation) but if you like I can consult with an expert - we have a big salmon and seatrout re-introduction scheme happening locally and Viv- the person in charge is an authority on rearing salmon

one of the fish they had for the hatchery last year...http://www.kilkeelanglingclub.btck.co.uk/Gallery/Fish

Nice sewin, especially for Irish rivers as the norm is for slightly smaller fish, hopeyou sent the scales to the celtic sea trout survey

 

[Tom Bick]

I can only add to this is despite the size of the salmon they are very unfit in that they are farmed in cages and not experienced with long spells of activity such as swimming against strong currents and perhaps not able to survive the flood.

Like most farmed animal they out grow their body in that they pile on bulk but the rest of the fish internal organs are under developed for the size of the fish and the stress of sudden activity can kill the fish.

In the wild river fish will seek out back water for a rest but not if you are caged.

 

[The Cumbrian]

Personally I am more inclined to go with jenkinsbrynmair explanation. This is a hatchery and as a result they hatchlings will be in tanks with a controlled flow of water through the tanks. At least all the hatcheries I have visited, (admittedly only 3 ) were using indoor tanks with controlled flow.

I accept all that has been said about farmed fish is very probably correct but I don't think it was the cause of death in this case.

 

[Tom Bick]

Perhaps you are right I just took it that they were adult fish and missed the bit about a hatchery.

 

[biglongdarren]

yea they were all adult fish tom, they are only in the hatchery to be stripped then released again after that,the yound fish are released into the rivers as fry.

 

[jenkinsbrynmair]

Obviously collected wild brood stock (same as our project) as with most gravid salmon, they lose condition and if they have been stripped need careful nursing to bring them back into condition, so that could have been a factor. HAve you had any dealing with Viv Bradshaw at Llynyfan hatchery? I'm sure he would be helpful with advice.

 

[gentle001]

salmon are generally more suspectable from pollution than sea trout

 

[Jimmy]

If you're interested in sea trout from rivers that drain into the Irish Sea the report here http://celticseatrout.com/ looks like it might keep you occupied over Christmas.
It's a massive report - 850 pages.

 

[user 6228]

river yellow ? thats chromium not iron...
teeth problems can result from chromium poisoning.
chromium is a common pollutant from metal working

 

[REDWOOD]

Pound for pound sea trout are stronger than salmon, if you hook a 4lb sea trout it would give you a better fight than a 7lb springer