Brown trout or sea trout?

Cap'n Fishy

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Yes & none of that bunch had been to sea.
OK, so my question is still...

Why would a fish stay for an extended period in an infertile river until it had struggled to reach the large size of 12 inches, before smolting?

Col
 

cgaines10

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OK, so my question is still...

Why would a fish stay for an extended period in an infertile river until it had struggled to reach the large size of 12 inches, before smolting?

Col
What's to say it struggled to get to 12"? there wasn't only a single fish at that size, there was many in the 10-12" category. We just see it as the norm, maybe it's worth looking into deeper.
 

Cap'n Fishy

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What's to say it struggled to get to 12"?
Well, all life is a struggle, for one thing! 😜

You are saying the river is poor in insect life. You would think, just applying logic, that the more nutrient/fly-life-poor rivers would send their juvenile trout to sea more quickly - when there are still plenty of them at the base of the pyramid of numbers. No? The longer the clock ticks, the more a generation of juveniles is thinned-out by predators. If it is a rich environment, the juveniles might be fast-growing, and it might pay them to put on enough weight to avoid marine predators by being able to delay smolting for a year. However, if life is a struggle, due to poor nutrients/fly life, are the numbers not going to be thinned out too much by waiting until they have attained 12 inches? Would it not be better to smolt when they are numerous and small, rather than few and big?

I dunno? I am just asking questions - but questions that seem reasonable to ask, given what you have said about 12-inch smolts in a nutrient-poor river.

Col
 

cgaines10

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Well, all life is a struggle, for one thing! 😜

You are saying the river is poor in insect life. You would think, just applying logic, that the more nutrient/fly-life-poor rivers would send their juvenile trout to sea more quickly - when there are still plenty of them at the base of the pyramid of numbers. No? The longer the clock ticks, the more a generation of juveniles is thinned-out by predators. If it is a rich environment, the juveniles might be fast-growing, and it might pay them to put on enough weight to avoid marine predators by being able to delay smolting for a year. However, if life is a struggle, due to poor nutrients/fly life, are the numbers not going to be thinned out too much by waiting until they have attained 12 inches? Would it not be better to smolt when they are numerous and small, rather than few and big?

I dunno? I am just asking questions - but questions that seem reasonable to ask, given what you have said about 12-inch smolts in a nutrient-poor river.

Col
I would say it's poor compared to other rivers I know & fish, however I wouldn't say its devoid of fly life. I suppose it's easy for us to try and apply logic, but a migratory fishes life cycle is very complex with a huge amount of issues at each step of the way. I can see where you're coming from though, but I don't know whether it's true or not to whether that is the reason they grow on. I would imagine that other rivers have a similar output to us?

Also there isn't a just a few and big, it's really a mixed bag with huge numbers of smolting typically each year at each size range.

I suppose a question for me would me with regards to the finnock you get in Scotland, how many have actually been to sea? or are they just going through the change and descending through the system.
 

Cap'n Fishy

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I suppose a question for me would me with regards to the finnock you get in Scotland, how many have actually been to sea? or are they just going through the change and descending through the system.
When the finnock come in fresh from the sea, they have sea lice on them. That is half the problem with the fish farms - the amount of sea lice on finnock just grinds them down and kills them.

This is not my photo, but I have witnessed it...



Col
 

cgaines10

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When the finnock come in fresh from the sea, they have sea lice on them. That is half the problem with the fish farms - the amount of sea lice on finnock just grinds them down and kills them.

This is not my photo, but I have witnessed it...



Col
Jesus that's horrendous. I've never seen anything like it on our systems thank god.
 

Cap'n Fishy

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Jesus that's horrendous. I've never seen anything like it on our systems thank god.
Here is a healthy finnock from Loch Hope (north coast - no fish farms close by)...



In a loch where a half pound brownie is a good one, there is not much doubt that wee porker has been in the sea! 😜
 

bobmiddlepoint

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I suppose a question for me would me with regards to the finnock you get in Scotland, how many have actually been to sea? or are they just going through the change and descending through the system.
The answer to that is all of them. Fish that are just going through the change and descending through the system are smolts not finnock!

FWIW every smolt I've ever seen has looked very different to the few overwintered finnock I've seen. For one thing smolts in the spring are well fed little fish and are pretty much in perfect condition with not scale out of place. Finnock that have overwintered in freshwater and are encountered in spring at the same time as smolts are skinny somewhat scruffy things often with missing scales. As Col says finnock encountered in summer have the obvious clue of sea lice. Also finnock smell different to trout or smolts, they somehow smell of the sea.


Andy
 

cgaines10

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The answer to that is all of them. Fish that are just going through the change and descending through the system are smolts not finnock!

FWIW every smolt I've ever seen has looked very different to the few overwintered finnock I've seen. For one thing smolts in the spring are well fed little fish and are pretty much in perfect condition with not scale out of place. Finnock that have overwintered in freshwater and are encountered in spring at the same time as smolts are skinny somewhat scruffy things often with missing scales. As Col says finnock encountered in summer have the obvious clue of sea lice. Also finnock smell different to trout or smolts, they somehow smell of the sea.


Andy
Yes, I know that. I was asking how you decipher that, as I have no reference as we don't seem to get these small finnock that you guys do in Scotland.

Thanks for the info.
 

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