Say Whaaa? Hatchery fish appear to harm wild stock.

[Jake Watrous]

Something you may have long suspected or believed, but may have lacked proof of, now seems to have even more evidence on its side--Hatchery salmon appear to harm wild stocks of salmon.

More evidence that releasing hatchery-reared native fish is harmful

The impacts of rearing and stocking non-native fish into watersheds where they don’t belong are well understood: undue competition for limited resources, hybridization, predation — the list goes on. In the American West, we’ve seen how introduced brook trout outcompete native cutthroat trout and...

www.hatchmag.com

 

[Rob Allen]

yeah, we have kinda known that for a while now. it's absolutely mind boggling that anyone is still studying it...

why does Montana have great trout fishing in their rivers? because they stopped planting them and that was back in the 50s or 60s..

 

[Jake Watrous]

yeah, we have kinda known that for a while now. it's absolutely mind boggling that anyone is still studying it...

why does Montana have great trout fishing in their rivers? because they stopped planting them and that was back in the 50s or 60s..

Anecdotal, to be sure, but I feel similarly about the Sol Duc’s numbers of steelhead vs other OP rivers.

Edit 4/13/23 5:44 pm: It appears the above statement is incorrect.

 

[HauntedByWaters]

yeah, we have kinda known that for a while now. it's absolutely mind boggling that anyone is still studying it...

why does Montana have great trout fishing in their rivers? because they stopped planting them and that was back in the 50s or 60s..

There are a lot of other reasons, mainly that they aren’t commercially harvested.

 

[Rob Allen]

There are a lot of other reasons, mainly that they aren’t commercially harvested.

Because trout don't taste good

 

[Stonedfish]

Some streams haven’t had hatchery steelhead planted in them for a number of years, but continue to struggle with recovering fish numbers.
I think it is a lot more complicated when it comes to anadromous fish than just pointing the finger at hatchery fish.
SF

 

[Jake Watrous]

Some streams haven’t had hatchery steelhead planted in them for a number of years, but continue to struggle with recovering fish numbers.
I think it is a lot more complicated when it comes to anadromous fish than just pointing the finger at hatchery fish.
SF

For sure. Death by 1000 cuts. For example, studies indicate a 50% fish mortality for salmonids passing under the bridges between Lake Washington and the Ballard Locks. Road runoff being claimed as the major source of that problem.

 

[Salmo_g]

The article reads like the study is a broad and high level overview of a condition that results from many contributory causes. In a nutshell, it's a straight forward conclusion that hatchery fish seldom, if ever, do any favors for wild fish. But the problems attributed to hatchery fish range from greatly exaggerated to being the proximate cause of wild fish extirpation, and every abundance level in between.

Smolt (and adult?) loss between the Lake Washington brigde and the Ballard Locks may be caused in part from road runoff, but I'd have to see some convincing evidence that it is the major problem, given all the problems causing fish loss there.

 

[PhilR]

I haven't had a chance to read through the paper, but it looks like they build a conceptual model and then studied that model on some streams in Japan where they have long term data on hatchery releases, returns, etc. I don't know enough to know if the results are generalizable, but my first reaction was "duh". My second reaction was, "wait, then why haven't the fish on my river come back with reduced hatchery plants?"

https://www.pnas.org/doi/10.1073/pnas.2218044120

Significance​

The intentional release of captive-bred individuals is a common practice for conservation and natural resource management. However, we know little about its potential consequences for the whole ecological community. Here, we show that the intentional release undermines community stability with limited demographic benefit to the enhanced species. Theory and data agree that intentional release destabilizes community dynamics by facilitating competitive exclusion while suppressing the natural recruitment of the enhanced species. The effect size of the intentional release was striking in its magnitude, doubling temporal fluctuations of enhanced communities compared to those with no intentional release. Our findings point to major limitations of intentional release as a primary tool for conservation and sustainability.

Abstract​

The massive release of captive-bred native species (“intentional release”) is a pervasive method to enhance wild populations of commercial and recreational species. However, such external inputs may disrupt the sensitive species interactions that allow competing species to coexist, potentially compromising long-term community stability. Here, we use theory and long-term data of stream fish communities to show that intentional release destabilizes community dynamics with limited demographic benefit to the enhanced species. Our theory predicted that intentional release intensifies interspecific competition, facilitating the competitive exclusion of unenhanced species that otherwise stably coexist. In parallel, the excessive input of captive-bred individuals suppressed the natural recruitment of the enhanced species via intensified within-species competition. Consequently, the ecological community with the intentional release is predicted to show reduced community density with unstable temporal dynamics. Consistent with this prediction, stream fish communities showed greater temporal fluctuations and fewer taxonomic richness in rivers with the intensive release of hatchery salmon—a major fishery resource worldwide. Our findings alarm that the current overreliance on intentional release may accelerate global biodiversity loss with undesired consequences for the provisioning of ecosystem services.

 

[Jake Watrous]

The article reads like the study is a broad and high level overview of a condition that results from many contributory causes. In a nutshell, it's a straight forward conclusion that hatchery fish seldom, if ever, do any favors for wild fish. But the problems attributed to hatchery fish range from greatly exaggerated to being the proximate cause of wild fish extirpation, and every abundance level in between.

Smolt (and adult?) loss between the Lake Washington brigde and the Ballard Locks may be caused in part from road runoff, but I'd have to see some convincing evidence that it is the major problem, given all the problems causing fish loss there.

Main cause for returning coho mortality:

6PPD: The Secret Killer of Puget Sound Salmon — The Nature Conservancy in Washington

Saving salmon and solving stormwater is a complicated business, but green infrastructure tools like rain gardens provide a first step to reducing the influx of toxins into local waterways.

www.washingtonnature.org

 

[brownheron]

Anecdotal, to be sure, but I feel similarly about the Sol Duc’s numbers of steelhead vs other OP rivers.

Counter-factual anecdote - pretty healthy salmon plant in the Sol Duc and those runs are doing well too.

 

[Jake Watrous]

Counter-factual anecdote - pretty healthy salmon plant in the Sol Duc and those runs are doing well too.

It appears I stand corrected.

Thank you for the correction.

 

[Bob N]

yeah, we have kinda known that for a while now. it's absolutely mind boggling that anyone is still studying it...

why does Montana have great trout fishing in their rivers? because they stopped planting them and that was back in the 50s or 60s..

Sorry Rob, the studies to determine if allowing natural reproduction on the Madison, the original study site, occurred in the mid 70’s. The final conclusion was in the late 70’s with the determination it was viable occurring in about 1979. After that Montana went for eliminating planting hatchery trout in streams across the state.

 

[brownheron]

It appears I stand corrected.

Thank you for the correction.

Hi Jake. Didn't mean it as a correction, more of an "it's complicated" that Salmo did a better job of saying as usual.

Salmon aren't steelhead and some life histories seem to be doing a lot better than others. At least on the Quil. system, my semi-uneducated view is that harvest (terminal and ocean) is the biggest barrier to recovery. The marginal benefits to hatchery reduction feel like just that, marginal compared to some of the other potential (and harder to implement) solutions.

I hate not being able to fish this month. And, when I last floated on 3/30, there were steelhead redds _everywhere_ that you would expect them. So I take some solace that the gravel seems to be well sown. Fingers crossed on what happens from here.

 

[O' Clarkii Stomias]

There is a strain of 1 salt, large, wild spawning summer runs that may of us enjoy catching in the fall that is the direct result of hatchery manipulation. They are a composite strain of several drainages that now spawn successfully on their own.

 

[Jake Watrous]

Hi Jake. Didn't mean it as a correction, more of an "it's complicated" that Salmo did a better job of saying as usual.

No worries. If I’m ever wrong, or there’s something I may not be fully seeing or considering, I appreciate getting new/better information. As they say, there is no knowledge that is not power.

 

[Grandpa Jim]

Hi Jake. Didn't mean it as a correction, more of an "it's complicated" that Salmo did a better job of saying as usual.

Salmon aren't steelhead and some life histories seem to be doing a lot better than others. At least on the Quil. system, my semi-uneducated view is that harvest (terminal and ocean) is the biggest barrier to recovery. The marginal benefits to hatchery reduction feel like just that, marginal compared to some of the other potential (and harder to implement) solutions.

I hate not being able to fish this month. And, when I last floated on 3/30, there were steelhead redds _everywhere_ that you would expect them. So I take some solace that the gravel seems to be well sown. Fingers crossed on what happens from here.

Great to hear your observation about #'s of steelhead redds on the Quil. system! February 6th this year was my last day out there this season. My impression from the three trips I made out to the OP in Jan & Feb was that it was shaping up to be a good run.
April has been my favorite time to fish the OP for steelhead. Wading more pleasant and fewer people. I would put away all my gear rods and only take my switch and spey. I would stay away from the upper watersheds and just swing runs on the lower rivers. Late April 2019 was my last steelhead on a wet fly...

 

[Rio Grande King]

Sorry Rob, the studies to determine if allowing natural reproduction on the Madison, the original study site, occurred in the mid 70’s. The final conclusion was in the late 70’s with the determination it was viable occurring in about 1979. After that Montana went for eliminating planting hatchery trout in streams across the state.

1974 Montana stopped stocking rivers. Credit mainly to Dick Vincent's work-Stocking

 

[O' Clarkii Stomias]

After just deleting a novel/rant on this subject, I will say that catch and release had more to do with the success of the Madison rather than the elimination of hatchery stocking of the river.

 

[Rob Allen]

As fishing pressure increased, massive stocking was seen as the panacea to keeping Madison anglers happy. That changed when research by Montana Fish, Wildlife & Parks (FWP) biologist Dick Vincent demonstrated that stocking actually reduced trout numbers in Madison control sections. Vincent’s science was the foundation of Montana’s groundbreaking 1974 decision to end stocking in the river, a move that eventually spread across the state and the country. As Vincent told FWP’s Montana Outdoors, “When we quit stocking the Madison, populations of wild trout, both rainbow and brown, just started to explode.” The Madison helped spark America’s wild trout revolution.