Study Analyzes Effects Of Supplementation on......

Posted by: OncyT

Study Analyzes Effects Of Supplementation on...... - 05/26/15 01:03 PM

Natural-origin Salmon Abundance:

Analyzing large-scale conservation interventions"

Summary: A recent study that compared 12 wild chinook salmon populations that had been the focus of hatchery supplementation programs and 10 populations of salmon that had never been the focus of supplementation programs found none to small benefits in natural salmon abundance.

The study analyzed information from a 25-year period and determined that densities of natural-origin spawning adult salmon in the Snake River Basin that had been the focus of supplementation programs had increased just 0 percent to 8.4 percent relative to the 10 salmon populations that had not been the focus of supplementation.

There could be several explanations for this, according to the study.

First, other studies have denoted the poor reproductive success of hatchery salmon and they could depress the abundance of wild adults, as well.

Second, the theoretical basis of supplementation assumes that target populations are well below carrying capacity, the study says, and the lackluster performance of supplementation shown in this study could be because populations are closer to carrying capacity than thought.
Posted by: Salmo g.

Re: Study Analyzes Effects Of Supplementation on...... - 05/27/15 08:30 AM

As time goes on, I'm increasingly convinced that the brutal reality of our fisheries situation is that we have compromised fish population carrying capacity far more than we thought we have. Among the stream rearing obligates of chinook, coho, and steelhead, harvest has pretty much been taken out of the equation south of latitude 49. Across the board, what's left but habitat productivity and capacity?
Posted by: milt roe

Re: Study Analyzes Effects Of Supplementation on...... - 05/27/15 09:56 AM

Marine environment and associated low smolt to adult survival.
Posted by: cncfish

Re: Study Analyzes Effects Of Supplementation on...... - 05/27/15 10:07 AM

has anybody studied the effects of supplemental feedings in stream?

can adding trout chow to the environment increase the overall population? will the larger population then sustain itself due to the larger nutrient base?
Posted by: FleaFlickr02

Re: Study Analyzes Effects Of Supplementation on...... - 05/27/15 10:27 AM

To play devil's advocate:

Someone once defined insanity as doing the same thing, over and over again, and expecting different results....

We model our salmon fisheries to kill every salmon, wild or hatchery, above established escapement goals. While we don't always do as well predicting how many fish will be available, we do a pretty fair job of harvesting down to the last paper fish. I think it's safe to say that in the modern era, escapements well above the floor are viewed as management failures. Evidently, our managers aren't failing very often in that regard.

It seems like more and more science is pointing the finger at habitat as the primary limiting factor in salmon abundance. It would be pretty arrogant (and misguided) for someone like me to say the science is fatally flawed, so I'll stop short of that, but I think it may be incomplete.

I recall from high school chemistry that any good experiment contains a control sample. If the hypothesis states that harvest is not a leading factor, shouldn't the observations include what happens when harvest (and I don't mean just in-river sport harvest) is removed from the equation? I realize why that experiment has not been conducted, and for the same reason, it's not likely that it will ever happen. I guess my point is that politically-tainted science, while it may yield results that help fisheries managers sleep at night, probably fails (often by design) to reveal the whole truth.
Posted by: FleaFlickr02

Re: Study Analyzes Effects Of Supplementation on...... - 05/27/15 10:40 AM

One more thing... Whatever the verdict on harvest, I think we all agree the ocean is a huge part of what determines overall abundance. It seems pretty clear that when we enjoy above average returns, we have the ocean to thank for it. Unfortunately, there is next to nothing we can do to control that. However, if ocean conditions are the reliable predictor of relative abundance we have come to understand they are, shouldn't we adapt our fisheries models to reduce impacts during years of low ocean survival? Well, as it stands, we don't do that. Instead, we continue to fish right down to or below escapement. Then we have to ask why hatchery supplementation isn't increasing wild abundance?
Posted by: OncyT

Re: Study Analyzes Effects Of Supplementation on...... - 05/27/15 12:55 PM

Salmo can correct me if I am wrong, but here is my take on the experiment you propose. There are several control populations in this experiment already. Those are the ones not supplemented. The test populations were supplemented and the general result is very little change. As far as harvest effects (again, Salmo, check me out), these are Snake River Spring/Summer Chinook that for all practical purposes have zero ocean harvest, so the in-river harvest is all you have. Between 1979 and 2013, the total in-river harvest rate ranged between ~4% and 17%, and in fact in some years fish were left on the table. Given these figures, it's really hard to argue that changing harvest would have any effect since harvest is already very low and since putting additional fish on the spawning grounds (through supplementation) had little effect. Obviously this doesn't address any potential reduction in productivity from hatchery fish, but just about everything that I've read suggests that even hatchery fish will produce well if there is a lot of unused habitat.

Harvest estimates from: Snake River Harvest Module, June 2014, prepared by the National Marine Fisheries Service, West Coast Region, Portland, OR.
Posted by: FleaFlickr02

Re: Study Analyzes Effects Of Supplementation on...... - 05/27/15 03:55 PM

OncyT:

I understand the argument that a non-supplemented population should be the control for the experiment being discussed in the article, and I suppose I agree.

I think you might be putting a little too much faith in that there are "zero" ocean fishery impacts on those fish, and even if that's true, there are in-river fisheries that do take a toll. Granted, there are no directed ocean fisheries for springers, but when we remember that a springer is really just a Chinook that migrates upstream at a different time of year, and that it spends the majority of its adult life at sea, comingled with other salmon, we realize that a lot of what gets labeled "small" Chinook in the summer and fall fisheries may actually be next year's springers. Again, not arguing that harvest is the key with those fish. God knows, if you want to see the full extent of habitat challenges firsthand, following some Snake Chinook around will show you the whole gamut. (Keep in mind that stream nutrient levels are among those challenges, and the big reason they're lower than what they were historically is that only about 10% of the potential carcasses are being added, year after year.) That there are any of those fish still swimming is testament to how resilient salmon are.

I'm not trying to dismiss the study, its findings, or its authors. I'm neither qualified nor inclined to do so. My point was (and has been) that as long as our harvest model is set up to maximize harvest, minimum survival is exactly what we should expect.
Posted by: OncyT

Re: Study Analyzes Effects Of Supplementation on...... - 05/27/15 04:03 PM

The assumption that there is little to no ocean harvest is based on coded-wire tag information over many years, as are the in-river harvest rates, so it is not a faith-based argument. Again, in this particular case, where harvest rates are very low (4% to 17%), not many people are going to buy that the harvest model for these populations is to maximize harvest as you suggest.
Posted by: OLD FB

Re: Study Analyzes Effects Of Supplementation on...... - 05/27/15 04:42 PM

Originally Posted By: FleaFlickr02
One more thing... Whatever the verdict on harvest, I think we all agree the ocean is a huge part of what determines overall abundance. It seems pretty clear that when we enjoy above average returns, we have the ocean to thank for it. Unfortunately, there is next to nothing we can do to control that. However, if ocean conditions are the reliable predictor of relative abundance we have come to understand they are, shouldn't we adapt our fisheries models to reduce impacts during years of low ocean survival? Well, as it stands, we don't do that. Instead, we continue to fish right down to or below escapement. Then we have to ask why hatchery supplementation isn't increasing wild abundance?


Thank you FleaFlickr02 your posts were right on the mark!
Posted by: TanTastic84

Re: Study Analyzes Effects Of Supplementation on...... - 05/27/15 10:29 PM

I personally think nature has a LENGTHY history of doing a decent job of repairing things on it's own. It's pretty obvious the main culprit in any and all animal species decline has been the direct result of human intervention. No matter how much we blame one thing or the other whether that be the environment, predation (natural and human consumption) or habitat destruction all signs point to us humans.

One thing we also love to do is try to correct our past mistakes. We set up quota systems that don't make sense or rules governing when, where and who can fish and for what but all you get are reports of rampant violations and continuously declining numbers of fish. The major hurdle is our inability to see past dollar signs both in economical and political forms so no matter what we try to do, our best efforts to build up species numbers usually has the opposite effect. It seems to me that if we really cared about what's happening with our oceans and our species then perhaps we should stop doing EVERYTHING to the species. Specifically, harvesting by everyone.....

Now, I know everyone here is going to bash me for saying it but if we really cared about our future generations getting opportunities to harvest salmon then maybe we should have some sort of system in place to let the salmon do their thing unmolested by man. Maybe have a system where we humans can only harvest (commercial, tribal and recreational) once every other year or every two years. Something that allows nature to do what it does best....fix itself. But that'll never happen because we who "care about our oceans" cant see past the here and now.

Anyway, it's late. I don't like to think too much before bed. It'll give me wrinkles.
Posted by: cncfish

Re: Study Analyzes Effects Of Supplementation on...... - 05/28/15 05:32 AM

FleaFlickr02,
I agree with your statement that the oceans are a problem and lack of nutrients in the watersheds are a problem. ( and harvest is also a problem)

I think we can all see that without some form of nutrient enhancement in both those places the system will collapse. you can't take the trees, and the fish and the deer, and the mushrooms and the berries from the land and not replace the nutrients that they will provide when dead. the question is where is the line between pollution and fertilizer? and then we have to figure out where that line is for the ocean also...

my concern is I do not see anyone working on those questions yet.
Posted by: Salmo g.

Re: Study Analyzes Effects Of Supplementation on...... - 05/28/15 01:39 PM

Milt Roe,

I should have included marine smolt to adult survival as part of the habitat productivity and capacity element. Although dramatically different, the ocean is an extension of salmonid habitat.

Cncfish,

Yes, supplemental feeding in streams has been tried in limited applications - controlled flow side channels. The concept has limited applicability and is not generally feasible. I don't know of any data indicating that the subsequent adult population is increased, and I doubt that any incremental increase would be subsequently sustained by the small incremental increase in the nutrient base, if any.

FF2,

In harvest management, escapement above the goal is a harvest management failure, as is escapement below the goal. Unfortunately the level of precision some folks want from harvest management is impossible, so I think harvest management can truly only be said to be failing when escapements consistently fail to meet the goal due to over-harvest. Some runs, like PS steelhead, are not harvested to any significant degree (< 4%), and still fail to make escapement. I'd have a hard time blaming that lack of fish on over-harvest.

OncyT,

I think there are about to be some more examples where supplementation failed to increase populations. The reason is the very topic of this thread, carrying capacity is less than thought. We can supplement a spawning population all we want, but that won't increase the intrinsic carrying capacity of a given habitat unit. This is gonna' screw up a whole lotta' recovery goals that were probably more "faith based" than ecology based.

Cncfish,

Nutrient enhancement can only serve to increase fish population abundance if nutrients are the limiting factor. While more nutrients would likely help; i.e., we see native char and some trout experience a beneficial response to large pink and chum salmon escapements, there are still major ecosystem elements in PNW river systems that are severely compromised. That results in reduced productivity and carrying capacity that cannot be offset by increased nutrients alone.

Sg
Posted by: FleaFlickr02

Re: Study Analyzes Effects Of Supplementation on...... - 05/28/15 03:48 PM

Sg:

I must agree that the state of steelhead would seem to put a gaping hole in my reasoning that chronic overharvest is the ultimate limiter. I'd like to be able to argue that Puget Sound, with the most compromised habitat in the state, is an exceptional case, but sadly, other steelhead populations seem to be doing very little better. Indeed, the wild steelhead numbers we see today may be very nearly as good as their environment will allow. I do wonder if perhaps steelhead, who spend more of their lives in-river than most salmon, are more adversely affected by the relative lack of stream nutrients (which would link them to the limitations facing salmon)... but that's really not much more than a WAG.

The case for salmon, who are subject to significant harvest, is obviously quite different. It may very well be that we're at carrying capacity for the remaining habitat. I question that, however, simply because I figure the tens of thousands of salmon harvested from the ocean every year must be coming from somewhere, and while I'm no fish biologist, I understand that somewhere to be the same rivers we're arguing can't support them. I realize that just because the rivers (with hatchery supplementation) produced those salmon doesn't mean that they can sustain the full adult population returning to spawn (or that if they did all spawn, any more smolts would survive than under the established escapement goals), but I find it frustrating that, as long as we continue to harvest to the status quo, we'll never know what would happen, and we'll never know what the true limitations (or cabilities) of the habitat are. It's all too typical of how humans deal with issues like this. If it comes down to someone's livelihood (or, more accurately, someone's cash cow) or the resource they exploit, it's resource be "dammed." Every time.
Posted by: Carcassman

Re: Study Analyzes Effects Of Supplementation on...... - 05/28/15 06:37 PM

The studies on the Keogh (steelhead) showed that fertilization with either fertilizers of carcasses increased smolt production. At the low marine survivals that were being seen at the time this actually resulted in the runs more than replacing themselves.

The Ford Arm studies in AK with coho showed that productivity chnaged with increasing pink escapement. At 0 escapement, the 60% HR management took 1,000 coho. At 2 kg/sq metre the same 60% HR took 5-8,000.

The fact that the supplementation may not have shown increased production only says that current productivity is being met by the management scheme in place.

Productive Capacity is not a single number. We know that coho can, if populations are high enough and instream productivity is high enough, will produce fry that smolt, fingerlings that smolt, fall smolts, and spring smolts. Lower productivity, lower escapements, and you get spring smolts which, as has been shown many times, will support some level of sustainable fishing.
Posted by: milt roe

Re: Study Analyzes Effects Of Supplementation on...... - 05/28/15 07:21 PM

Now we are getting somewhere, I have nearly given up on this board because the same old patronizing BS gets tossed out by the same high posters every time recovery comes up for conversation. Lets talk about science and data. Keogh is a great example.
Posted by: Keta

Re: Study Analyzes Effects Of Supplementation on...... - 05/28/15 11:19 PM

the Skagit and the Snohomish have drastically decreased their carrying capacity for chum salmon the last several years. Must have been a big change in the river . I wonder what that was,
Posted by: Carcassman

Re: Study Analyzes Effects Of Supplementation on...... - 05/29/15 06:39 AM

How did they decrease their carrying capacity? What measures?
Posted by: cncfish

Re: Study Analyzes Effects Of Supplementation on...... - 05/29/15 08:57 AM

Salmo g.

I agree that river structure is also a limiting factor. puget sound rivers no longer look like Oly Pen rivers or Alaska rivers. I believe they should look similar. much more large woody debris, much wider flood plains more meandering, It goes back to the death of a thousand cuts argument.

I am frustrated that here we have yet another study as to whether or not hatcheries work. when we should be studying the other 999 cuts to see if we can help some of those. I know I don't have the answer. but throwing money at getting rid of hatcheries, or supporting them is a distraction. the solution is going to take a lot of band aids, not one big crutch.
Posted by: Keta

Re: Study Analyzes Effects Of Supplementation on...... - 05/29/15 10:09 AM

Originally Posted By: Carcassman
How did they decrease their carrying capacity? What measures?

I was being a bit cynical. The measure is those rivers were open to sport fishing chums and had a lot of fish. Now they are closed and have few fish. They were netted into oblivion,roe prices went way up.
Posted by: Salmo g.

Re: Study Analyzes Effects Of Supplementation on...... - 05/29/15 10:16 AM

Milt,

I'm not sure what the patronizing BS is that you're referring to, but I'd like to see recovery related discussions that refer to science and data. I'm concerned that some of the recovery goals may be fueled more by emotion than ecosystem productivity.

Keta,

Are you referring to the huge increase in pink salmon abundance in PS? I don't know if it's causal, but pink salmon fry hit the estuary before chum and chinook fry do, and I think they forage on many of the same food sources. The increase in pinks does correlate with the recent decline in natural production of chum and chinook, so pinks could be part of the cause.

Cncfish,

I think we know that hatcheries work. Hatcheries work to create abundant supplies of hatchery fish. Hatcheries can only improve naturally reproducing populations if they are managed for that purpose, and the overwhelming majority are not. And even when they are managed to improve wild populations, they can only do so if natural habitat is currently under-utilized.

Sg
Posted by: Keta

Re: Study Analyzes Effects Of Supplementation on...... - 05/29/15 11:31 AM

SG, I understand how complicated salmon interactions are and have observed a lower return of chum related to the pink cycle. I also know the chum salmon in those rivers were doing quit well even with large pink runs in the mix. I also know the chum were hammered hard when the Asian roe market demand raised the price of roe way up. I know you fish the Skagit and I'm sure you have noticed the drastic lower abundance of chum. It was only a few years ago the Skagit was full of chum, now so few it's closed to sport fishing? I'm having a hard time putting that much blame for that big of change in that short of time on humpies. I do remember when the Baker Dam operation dried up a bunch of chum reds and that didn't help so I'm not blaming it all on netters and that incident wouldn't have been so bad if the chums weren't already fished down to minimum escapement. All I can do is connect the dot,of which there are many, but I can't get past my observation of a more extensive targeting of chum for their roe. I just wonder about how the lack of nutrients from the chum salmon effect the overall carrying capacity of these rivers. I apologize for the lack of data. I tried to find catch records on WDFW but data is not up to date.
Posted by: eyeFISH

Re: Study Analyzes Effects Of Supplementation on...... - 05/29/15 11:47 AM

Originally Posted By: Salmo g.


I think we know that hatcheries work. Hatcheries work to create abundant supplies of hatchery fish. Hatcheries can only improve naturally reproducing populations if they are managed for that purpose, and the overwhelming majority are not. And even when they are managed to improve wild populations, they can only do so if natural habitat is currently under-utilized.

Sg


+1,000,000,000,000,000,000,000,000,000,000,000,000

This should be the lead post for any hatchery debate... you know, before it turns into a train wreck of emotional BS
Posted by: JustBecause

Re: Study Analyzes Effects Of Supplementation on...... - 05/29/15 11:48 AM

Keta,

Go to this link for the Puget Sound commercial regs, download the regs. Toward the front there are a series of harvest tables split out by area and species. They cover about the last decade of fisheries.

http://wdfw.wa.gov/fishing/commercial/salmon/
Posted by: Carcassman

Re: Study Analyzes Effects Of Supplementation on...... - 05/29/15 11:54 AM

That the NI commercial or all commercial?
Posted by: cncfish

Re: Study Analyzes Effects Of Supplementation on...... - 05/29/15 12:14 PM

I just want to see the big headline debate to switch from something we know to something like "study links septic run off to periwinkle population"
or "drop in sticklebacks linked to excessive merganser predation"

because maybe, just maybe hatcheries or lack of them are not the problem.
Posted by: eyeFISH

Re: Study Analyzes Effects Of Supplementation on...... - 05/29/15 12:24 PM

Originally Posted By: cncfish


because maybe, just maybe hatcheries or lack of them are not the problem.


The article says NOTHING about whether or not hatcheries are "the problem"

It simply states they are a USELESS tool for boosting natural production from the gravel....nothing more, nothing less.
Posted by: eyeFISH

Re: Study Analyzes Effects Of Supplementation on...... - 05/29/15 12:30 PM

Originally Posted By: cncfish
I just want to see the big headline debate to switch from something we know to something like "study links septic run off to periwinkle population"
or "drop in sticklebacks linked to excessive merganser predation"


I believe the paper has merit, and the effort to study it was worthwhile. Obviously, the conclusions of the paper were not the obvious "no brainer" some may think.

If the conclusion was so obvious, why have we spent 25 years pouring billions of dollars into an investment with ZERO return?

Outcomes-based management.... whether in business, health care, or fisheries management... should be embraced. The only issue for me is why it took 25 years to realize supplementation hatcheries like this are a total waste of time talent and trea$ure.
Posted by: cncfish

Re: Study Analyzes Effects Of Supplementation on...... - 05/29/15 01:29 PM

eyeFISH,
I disagree with your conclusion from the study. what I see in the study is that in this case and point adding more fish to the mix did nothing for the population, due to other constraints in the system.

many other cases state hatchery supplementation works fine. see the great lakes, or South America. naturally reproducing populations of pacific salmon, from hatchery supplemental plants.

hatchery's are tools. nothing more. not a silver bullet that will solve all the issues. we need to learn what the other issues are and find a way to fix them so that the fish populations can recover.

whether or not the paper has merit depends on how it is used. you choose to use it to claim we should abandon all hatcheries. I choose to use it to shed light on other issues. maybe get funding for other studies that are on things that maybe will solve the problem.
Posted by: FleaFlickr02

Re: Study Analyzes Effects Of Supplementation on...... - 05/29/15 01:50 PM

Originally Posted By: eyeFISH
Originally Posted By: Salmo g.


I think we know that hatcheries work. Hatcheries work to create abundant supplies of hatchery fish. Hatcheries can only improve naturally reproducing populations if they are managed for that purpose, and the overwhelming majority are not. And even when they are managed to improve wild populations, they can only do so if natural habitat is currently under-utilized.

Sg


+1,000,000,000,000,000,000,000,000,000,000,000,000

This should be the lead post for any hatchery debate... you know, before it turns into a train wreck of emotional BS


I think Sg hit it perfect with that statement. It's not the hatcheries, but how they are managed. I'm of the belief that the salmon management paradigm we use in WA makes it abundantly clear that there has not been any intention to use hatchery salmon as a recovery tool for some time. Rather, they are produced to supplement overall abundance and justify more liberal fisheries. Commercial welfare (and, to a lesser extent, sport fishing welfare), if you will.

I would argue that, under the current paradigm, hatchery supplementation actually harms wild populations by providing justification for non-selective fishing methods to exceed modeled impacts, because, you know, AHFMD.
Posted by: eyeFISH

Re: Study Analyzes Effects Of Supplementation on...... - 05/29/15 01:55 PM

Originally Posted By: cncfish


many other cases state hatchery supplementation works fine. see the great lakes, or South America. naturally reproducing populations of pacific salmon, from hatchery supplemental plants.



Those examples are emphatically NOT supplementation programs.

They were introduction programs where a totally non-native population was introduced where none had been there to occupy the unutilized niche that allowed them to take hold in the first place.

The paper is VERY narrow in focus.

We're talking about currently existing, albeit depressed, wild populations. Hatchery supplementation has failed to grow those natural populations.

10 years ago, most folks were still blindly clinging to the "no brainer" belief that dumping more fish into those depressed systems could only help. J F C... how could it not?

Well now we have a definitive retrospective evaluation... an outcomes-based assessment of our investment in blind faith. And it ain't lookin' pretty.

In another 10 years we'll all look back and say, well hell that was a no brainer... who in their right mind could have ever thought that would work.