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#11
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Willi wrote:
I disagree. IMO, by carefully managing hatcheries the result can be more natural, but hatchery produced fish will always be different than naturally spawned wild fish. Hatcheries are a last resort for restoring native, wild fish populations. I agree with you, Willi, but with the caveat that I think hatcheries could be much more effective than they are now, but it would cost money. I suspect that a big problem (maybe THE problem) is that the fish that are raised and survive in hatcheries are those best adapted to hatchery conditions, which are very benign compared to wild conditions. They don't have to deal with predators, weather and water conditions, and diseases in the same way that wild fish do. In the end, you get a cohort of fish that hasn't been culled by natural conditions, so there is a "drift" of their genetics toward adaptation to man-made hatchery conditions. In principle, these problems could be addressed by more natural conditions in the hatchery, but the cost would be very high. |
#12
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#13
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Hi,
The Margaree is sort of holding its own. Lats season was not good for the early run (June and early July), but was very good for the late run, which holds the multi-sea-year fish and occurs in September/October. The good news we thought we were getting was that the hatchery is being upgraded and will hatch more salmon and place more egg boxes this year - which was the reason for the concern over the news that a State court had actually judged that hatchery fish would have to be included in river counts - that would destroy the Margaree. The other sad news about the Margaree is that it was found that at least one smallmouth bass was in Lake Ainslie (at the headwaters of the NE Margaree). This has seen DNR put an extended double bag limit of bass on that population, and a longer season in anattempt to limit the impact of these fish on the salmon. Hopefully they will stick around only in Ainslie and not get into the river proper. Only time will tell I suppose. The North is really coming back however, due to the re-building of the banks below the bridge so that the water runs wild like it used to before they tried to channel it. The river had a very good early run of both sea-trout and salmon last season. Bill http://www.tightlines.ca |
#14
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Bill wrote:
The part that got my attention was: "A federal judge in Eugene ruled three years ago that the Fisheries Service had to count hatchery fish when it evaluated the strength of salmon stocks. That caused Oregon Coastal Coho salmon to be removed from the threatened species list." ....snip....... The Atlantic Salmon is an endangered fish, if they ever forced the feds up here to count the released hatchery fish as part of the bio-mass, then it's game over for these fish....... Precisely. Development, mining, and logging interests that are trying to confuse the issue. There is great pressure from these lobbies to blur the distinction between hatchery fish and wild fish. In most places in the PNW, hatchery steelhead and salmon are physically marked somehow, usually by fin-clipping. Once you include hatchery fish in counts used to determine stock strengths, you then can go on to maintain that wild and hatchery fish are essentially the same (this argument is already being made by the development interests), and later to stop altogether distinguishing wild fish from hatchery fish in any way for management purposes (again, currently being urged, and in the case of some tribal hatchery operations, already being done). Relying on hatcheries alone has failed in Atlantic salmon restoration. Relying on hatchery output *alone* (or even primarily) to save wild steelhead and Pacific salmon in the PNW will also fail. Hatchery fish, produced only from truly wild brood stock and in numbers *as small a possible* to take angling pressure off wild fish, can perhaps play a valuable but *minor* stop-gap role, but only as a supplement to the much more important efforts to maintain and restore viable habitat (and eventually, I believe, to the breaching of a large number of dams). These critical habitat restoration efforts are what stick in the craw of the pro-development interests, which is why they are actively trying to muddy the waters. Some more background on the panel's findings, and why they were ignored by the National Marine Fisheries Service, for those who are interested: Eureka Alert: "Government appointed panel of scientists responds to NMFS 'Censorship' by publishing in Science"" http://tinyurl.com/2oykz Seattle Times: "Salmon panel goes public in dispute over hatchery fish" http://tinyurl.com/35l22 San Francisco Chronicle: "Salmon jeopardized by method used in run count" http://tinyurl.com/225f9 JR |
#15
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![]() rw wrote: Willi wrote: I disagree. IMO, by carefully managing hatcheries the result can be more natural, but hatchery produced fish will always be different than naturally spawned wild fish. Hatcheries are a last resort for restoring native, wild fish populations. I agree with you, Willi, but with the caveat that I think hatcheries could be much more effective than they are now, but it would cost money. I suspect that a big problem (maybe THE problem) is that the fish that are raised and survive in hatcheries are those best adapted to hatchery conditions, which are very benign compared to wild conditions. They don't have to deal with predators, weather and water conditions, and diseases in the same way that wild fish do. In the end, you get a cohort of fish that hasn't been culled by natural conditions, so there is a "drift" of their genetics toward adaptation to man-made hatchery conditions. In principle, these problems could be addressed by more natural conditions in the hatchery, but the cost would be very high. I don't get your point. If these "natural" conditions were reproduced in the hatcheries, the resulting mortality would be the same as in stream bred fish. If that's the case, why not just use the stream as the hatchery. Instead of spending money on the hatchery and the fish for stocking, use the money to improve the conditions for natural reproduction. I seeing stocking as having two main uses: 1. To provide a put and take fishery in places where natural reproduction isn't possible (However, in cases like that I question if the fish being stocked belong in those waters) 2. As a stop gap method to supplement or reintroduce a native fish population. If this needs to be an ongoing program, something is wrong with the fishes' environment and that needs to be addressed if the fishery is ever going to change from a man made one to a natural self sustaining one. Supplementing hatchery stock on top of a naturally reproducing population of the species of fish causes lots of problems. In many cases it the reduces the reproduction success of the stream bred fishes. Willi |
#16
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Willi wrote:
I don't get your point. Some hatcheries supplement declining species of anadromous fish. The Sawtooth Hatchery near Stanley, for example, breeds and stocks steelhead, chinook, and sockeye. The fish aren't declining because of poor spawning habitat. That's nearly pristine. The main cause of the decline is almost certainly a series of dams on the Lower Snake and the Columbia. (Although there's plenty of disagreement among politicians about that, there's little disagreement among fisheries biologists.) The ultimate solution is to remove some or all of the dams, and eventually that will happen, because they make no economic sense. In the meantime, the hatcheries are a stopgap measure. Your Point 2. My point is that if hatcheries must be used, even temporarily, they could possibly be used in a better way -- in a way that minimizes genetic problems. But it would cost more money. |
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