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Gus

anglers show restraint

http://news.bbc.co.uk/2/hi/uk_news/scotland/6261029.stm

Good news if you're a Tay salmon.
KILLITnGRILLIT

I gave up 2 club memberships on the Tay years ago as I don`t think there are enough Salmon on the river and catch and release isn`t an option as far as I`m concerned.
The seals,goosanders and cormorants however are still fishing Mad
Gus

I'm curious to know your objections to C&R, KillitnGrillit. There have been many independent studies from all four major Atlantic Salmon countries, as well as from the russian Kola fisheries, and they all bear out the fact that properly practised C&R is massively beneficial to stocks.

I agree with the predator problem to some extent. I do find it hard to blame seals and cormorants etc for turning their attentions to salmon and trout however; Our poor management of whitefish stocks have driven most of these predators to diversify from their preferred prey.
tahir

Gus, what's the volume of salmon taken nowadays compared with say 10 and 20 years ago? (over Scotland as a whole)
Gus

Rod and line caught salmon numbers have remained fairly steady since records began, with a few exceptional highs and lows. Numbers dropped quite substantially after what were seen as the 'heydays' of 1950 - 1970, but in the past 10 years they have begun to increase again - no small coincidence that the numbers go up alongside the number catch and release policies being adopted by fisheries. The impact on salmon numbers as a whole from rod and line anglers is minimal, all the more so when catch and release rules are practiced in well managed fisheries.

Rod and line catches have increased slightly in the past decade from around 65,000 to over 70,000 based on 5yr averages. On pro-active C&R rivers such as the Dee and the Tweed, these increases have been proportionally much higher.
mick ball

for my mind the reason rod and line catches have gone up is because the netting licences are being baught up so letting more fish swim up river.
Gus

It's a contributary factor, no doubt. But fish mortality at sea is really the problem. We're eradicating the natural food supply of the salmon at an industrial rate, so even though removing nets might boost the numbers a bit, overall they are still in decline. Salmon farms are probably the single most damaging factor to wild salmon numbers as far as human activity is concerned.
tahir

Gus wrote:
Salmon farms are probably the single most damaging factor to wild salmon numbers as far as human activity is concerned.


Always worried me. How can you be so sure though?
Gus

The mortality rates to seaward travelling smolts (young salmon) can be horrendously high. A river should be viewed as a 'smolt factory', and even if it's running at its maximum capacity, a salmon farm in the estuary of that river could potentially wipe out 100% of the production run.

Salmon farming threatens the smolts of sea trout in exactly the same way.
tahir

Gus wrote:
a salmon farm in the estuary of that river could potentially wipe out 100% of the production run.


How?
Gus

Salmon farms attract artificially high concentrations of sea-lice, a natural parasite of atlantic salmon. The 'battery' style farm cages which are overcrowded with samon, attract billions of sea lice to the extent that the fish can become infested - not a good look when it comes to selling them. Sea lice look like skinny tadpoles with long tails clinging to the fish- unmistakeably parasitic and although harmless to humans, will put buyers off.

The cages are dosed with chemicals which under COSHH laws can only be used in concentrations which make the sea lice release their grip on their hosts (the caged salmon) from where they fall to the bed of the estuary. Smolts leaving the river then have to run this gauntlet. While a dozen sea lice on an adult salmon will cause it no harm at all, three sealice attached to a smolt weighing only a few ounces will bleed it dry and kill it. Because of their anadromous nature, salmon smolts all come from freshwater rivers and consequently must all pass under any sea cages in the mouth of the river. (as do sea trout smolts which sadly are even more vulnerable since sea trout rarely venture more than 3km from the mouth of the river they were spawned.)

Incidentally, anyone living on the west coast of scotland or ireland should be aware that the increase in toxic algal blooms which render the shellfishing in these areas unviable, has been linked to the increase in effluent from salmon farms causing overenrichment in the estuarine waters around the cages.
tahir

Thanks Gus. I've never been a fan of aquaculture, even less so now.
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