Nez Perce study on effects of Hatchery salmon

Salty

2012-10-10 16:36:01

New study shows that Nez Perce hatchery produces salmon as productive as wild fish

Submitted by Rocky Barker on Wed, 10/03/2012 - 10:02am, updated on Wed, 10/03/2012 - 10:51am

For years biologists have clashed over the role that hatcheries should play in restoring salmon.

Tribal biologists have followed the lead of Indian fisherman pushing supplementation of wild stocks of salmon with hatchery stocks. Previous research and genetic experiments have suggested releasing hatchery stock into the wild weakens the genetics of the wild stocks and reduces the overall productivity of the surviving fish.

So you had the tribal view that "a fish is a fish," versus the view that the genetic purity of the native fish evolved in its watershed made it superior. Over the last 20 years the two sides have come together a bit, still, the divide remains.

But a new study published this week in the journal Molecular Ecology shows that Nez Perce Tribe’s Johnson Creek Artificial Propagation Enhancement got the same reproductive success from hatchery-reared salmon that spawned with wild salmon as salmon left to spawn in the wild.

“The Johnson Creek research clearly demonstrates how supplementation programs can boost populations and minimize impacts to wild fish populations,” said Dave Johnson, Nez Perce Tribe Fisheries Program Manager.

The study used DNA from all returning adults collected over a 13-year period to track parents and their offspring, much as Idaho Fish and Game does in its sockeye program. It also showed biologists how successful hatchery fish were at mating in the wild when compared to wild fish.

The study showed fish taken in to the hatchery produced an average of nearly five times the number of returning adults compared to the fish that were left in the wild to spawn. Hatchery fish that spawned naturally with a wild fish had equivalent reproductive success as two wild fish, suggesting that chinook salmon reared for a single generation in the specially-designed hatchery did not reduce the fitness of wild fish.

It also showed that productivity of two hatchery fish spawning naturally was not significantly lower than for two wild fish.

The study focused on the Johnson Creek chinook salmon, who spawn in a tributary of the South Fork of the Salmon River nea Yellow Pine. It lies almost 700 miles upstream from the Pacific Ocean.

“Our results question the generalization that all hatchery fish negatively impact the fitness of wild populations,” said Maureen Hess, geneticist with the Columbia River Inter-Tribal Fish Commission and lead author on the study.

The Nez Perce Tribe began the Johnson Creek project in 1998 after salmon returns had dropped to as low as five in 1995. Today returns exceed 350 adults consistently and have reached more than 1,000 several times.

I joined Silas Whitman, now chairman of the Nez Perce Tribal Executive Committee, during a spring release of smolts in the 1990s when he was in charge of fisheries. Salmon were still in the emergency room then and he was pushing for expanding hatchery supplementation dismissing geneticist critics.

Today the tribes can point to successful programs throughout the Columbia Basin where their enhanced hatcheries and careful genetic techniques have produced success.

“The Johnson Creek study is just one example out of several supplementation programs that play a significant role in recovering Columbia Basin salmon runs," Whitman said.

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Read more here: http://voices.idahostatesman.com/2012/10/03/rockybarker/new_study_shows_nez_perce_hatchery_produces_salmon_productive_wi#storylink=cpy

SilverT

2012-10-13 05:16:08

Thanks for that Salty,

I sent a copy straight to WDFW. It seems man tends to make decisions much like the pendulum on a clock, swinging one way & then wildly overcorrecting. Washington has done that with their hatchery program.

I wish Washington would abandon the pretense that the wild runs in Washington State are each a pure strain of salmon, untainted by decades of hatchery reared salmon mixing with them in spawning grounds. Salmon occasionally stray and spawn in another stream, thereby mixing genes. That is the way it has always been.

I also wish the State would acknowledge that "marked" coho are getting smaller every year compared to their unmarked and perhaps tribally raised counterparts (this year they consistently averaged between 1-2 lbs less) and take steps to correct the trend. Smaller marked fish have been a trend for years, but this year showed the highest contrast in size. I would blame this on nature's success, but the difference is so consistent and the marked fish so grossly undersized compared to their unmarked, average sized counterparts, that I cannot help but consider that the State has completely isolated their broodstock. I'm assuming they breed only the returning, very small sized strain.

Hopefully we will see the pendulum nearer to the middle some day and see hatcheries used frequently and more wisely than ever. I want "wild" runs to be sustainable and restored to their original glory. The current policies are not getting us there because they are based on this purist mentality that hatchery fish are all bad, so-called wild fish are good, and mixing any of them together is taboo. Great for the budget, great for the Department, bad for the fish, bad for the fishers.

We have had the marked program for years and the so-called pure strains are still dwindling in places. It isn't working well or we would see the great return of the "wild" fish Washington State has so focused on preserving. As it is, we just maintain the status quo. The so-called wild fish need a boost. We now have a coast-wide agreement and better habitat laws that could protect the gains we might make through wise-use of a better hatchery program. The State has to defend their handling of what they or the Feds define as an endangered species of salmon. I'm not a scientist, but I really question the so-called purity of every salmon run in the State of Washington. And to that end, I question the validity of such an expensive, time consuming, unethical program as the fin-clip program.

Thanks again for the post & link.

Lane

Salty

2012-10-13 16:19:12

Lane,

Good comments, I agree. I actually do have a science degree and a hatchery degree and I see a lot of sense in your thinking. It is clear to me that protection of wild stocks must be our number one priority. But it also appears to me that adapting our programs to the real world of massive and long term hatchery infusions into the system for a variety of reasons, enhancement, rehabilitation, mitigation, research etc. needs to be accomplished. Personally I am not very worried about some mixing of genes in the wild spawning environment. What I am concerned about is crowding, disease, and overharvest impacts on wild salmon if hatchery programs are not managed well. Undoubtedly there will be future studies with different conclusions than the one posted here.

While salmon hatcheries have not proven to be the success we hoped in large parts of the NW and certainly have not mitigated habitat loss due to dams, irrigation, development, etc. they have helped sustain many of our salmon runs and fisheries to the point that we are dependent on their continuation as we try to restore natural habitat and runs where ever possible.

It is interesting that in Alaska, the home of the wild salmon runs, with the best wild salmon priority legislation in the world (I nominated Senator Dick Eliason to the salmon hall of fame for his work on that legislation) nearly half the value of our salmon now comes from hatchery incubated salmon.

SilverT

2012-10-14 18:30:35

Salty,

Nice that you have that background. That probably helps quite a bit when you're addressing issues with the game department. Washington has a long ways to go regarding habitat protection. From a layman's perspective, our main problem appears to be siltation of the stream beds. Logging operations have required buffers, but they are simply not enough to prevent siltation with the heavy rains we get here.

It amazes me how Washington State clear-cuts entire valleys and leave about 50-200 feet of vegetation around the stream, pretending that the thin strip of vegetation will somehow clear all the fines out of the storm-water runoff. For every commercial development project where clearing is required, an erosion control plan, construction entrance to clear mud off tires, filter fabric fencing to strain silts from the water, storm-water settling ponds and revegetation plans are required and enforced. This is on flat land, where little erosion occurs. In the steep valleys and mountainous regions, the State of Washington not only neglects these in their logging operations, the year after they clear-cut an area, they helicopter spray poison to kill the vegetation that competes with the new trees they plant. Steep slopes, completely decimated vegetation and no erosion control measures combine to create an insane amount of erosion and subsequent siltation of streams. As you are aware, that siltation kills the "wild" salmon eggs by smothering them.

Commercial developers pay through the nose for erosion control measures that largely work, but the State of Washington and the major private tree farmers in Washington get away with storm-water runoff violations that if exposed, might significantly change their operations. The violations are largely ignored, because they are out of sight, up in the forest, as apposed to the big-box development on the 3-lane arterial. It's no mystery to me why the rivers are chocolate brown in the heavy rains. They've done a really good job of keeping this quiet.

You mentioned disease and it reminded me that about 50% of the marked hatchery coho also had what appeared to be Myxobolus squamalis (little bumps all over their sides). The pamphlet I read on it said that they catch the disease in fresh water, so there's another task for Washington State to address at the few hatcheries we still maintain.

Thanks again,

Lane