Fishing with Rod Discussion Forum
Fishing in British Columbia => General Discussion => Topic started by: bluenoser on October 15, 2011, 11:16:03 AM
-
I've always wondered why the retention limit on several rivers is 4 marked fish per day. You would think if more were able to spawn it would be better for the species, yet on this and other forums many often comment that hatchery fish are there for us to catch not to reproduce...seems odd.
After doing alot of reading it seems that studies have shown the mortality rate of hatchery fish is much worse than wild stocks and that this carries on with the offspring of returning hatchery raised fish even when they mate with wild. They think that changing the way they are raised in the hatchery may help but that remains to be seen.
I'm originally from Nova Scotia and the rivers where I fished as boy changed regulations over the years to save the salmon stocks. Limit of 10 per year, all fish over 24.5 inches released, if the water level was low fishing was suspended....and so on. No hatchery fish program was ever set up, one excuse used was that acid rain was to blame and nothing could be done. Today those rivers have no salmon....none....salmon fishing has been closed for several years....they didn't even try a hatchery program.
Any comments from anyone more versed in this hatchery vs wild subject?
BN
-
The more scientific literature I read, the more it would seem that the typical hatchery process doesn't significantly contribute to the health of wild populations. In fact, it is likely that they may even add further pressure on wild stocks.
To understand this, the distinction in "fitness"must be made between wild and hatchery fish. Wild fish arise from the natural spawning of two fish, obviously. The healthiest, most viable spawners get the best spawning grounds and the most desirable mates, the combination of good genes and good redds leads to high survival amongst the offspring of this favortable pairing. In contrast, weaker fish get less desirable mates and spawn in marginal spawning grounds. The result is a lower survival rate amongst this less-successful group of fish. This "survival of the fittest" mechanism drives the continuation of a strong population of salmonids.
Hatchery fish on the other hand, arise from a random pairing of a male and a female (assuming hatcheries have enough brood to spawn 1 female/1 male). Through random chance, a desirable female might be paired with the gametes of an undesirable male. The result of this pairing reduces the fitness of desirable female's progeny. In nature, the undesirable male would not have had much of a chance to reproduce and his set of undesirable genes would might be eliminated from the gene pool, thus increasing the overall health of the genepool. Through the hatchery process, the elimination of less-desirable fish at spawning does not occur and healthy fish cannot select healthy mates through random pairing of spawners.
When the juveniles hatch, the close quarters of hatcheries may cause an increase in cortisol levels which may cause juvenile hatchery fish to become more voracious feeders (Garner et al, 2010). The size at release is often larger amongst hatchery fish, and they are potentially more aggressive, driving their wild counterparts out of the optimal feeding areas. The increase in total juvenile numbers may evoke whats called a type III functional response where predators are attracted by the density of the prey (juvenile steelhead), increasing the overall predation on the population. Furthermore, hatchery fish that return to rivers are less successful in spawning, however if they do successfully manage to mate, their less-desirable genes are passed on and reduce the genetic fitness of the population. Furthermore, they take up spawning area and may dig up the redds of wild fish if they should spawn later than a wild pair.
I think hatcheries have their place in several instances:
a) to support a fish an artificial fish population in an otherwise unhealthy rivers such as the Capilano where the Cleveland Dam has blocked access to spawning grounds and stopped cut off the supply of gravel to the lower reaches. Some salmon and steelhead still successfully spawn in-river, but there is little spawning habitat available due to the unfortunate placement of the Cleveland Dam.
b) provide a productive harvest fishery. People like eating fish, those people pay taxes too, so enhancing some rivers to provide this opportunity is fair and provides opportunity for businesses such as tackle shops, guiding, river-side accommodation etc.
I believe the best (only?) way to restore a wild population of fish is through habitat enhancement. This could take the form of installing fish-friendly culverts on coho tributaries, to ensuring the presence of proper gravel in spawning beds, to protecting riparian zones, marshes, estuaries, making sure there's structure in a stream, even stream fertilization.
-
I've always wondered why the retention limit on several rivers is 4 marked fish per day. You would think if more were able to spawn it would be better for the species, yet on this and other forums many often comment that hatchery fish are there for us to catch not to reproduce...seems odd.
Matt's explanation of the genetic inferiority of the hatchery fish does a good job of explaining why it is better if hatchery fish is caught and killed, as opposed to allowing it to compete with wild fish for spawning habitat. The purpose of the hatchery program is to allow fisherman opportunities to catch and kill fish in waters that do not produce enough fish to allow retention of wild stocks. This is supposed to take the pressure off the wild fish, which are released to spawn. This does, of course, create a dilemma for those who practice Catch and Release as a general rule. Does the release of that hatchery fish (purportedly to allow another fisherman the opportunity to catch it too), offer more harm than good?
-
The more scientific literature I read, the more it would seem that the typical hatchery process doesn't significantly contribute to the health of wild populations. In fact, it is likely that they may even add further pressure on wild stocks.
To understand this, the distinction in "fitness"must be made between wild and hatchery fish. Wild fish arise from the natural spawning of two fish, obviously. The healthiest, most viable spawners get the best spawning grounds and the most desirable mates, the combination of good genes and good redds leads to high survival amongst the offspring of this favortable pairing. In contrast, weaker fish get less desirable mates and spawn in marginal spawning grounds. The result is a lower survival rate amongst this less-successful group of fish. This "survival of the fittest" mechanism drives the continuation of a strong population of salmonids.
Hatchery fish on the other hand, arise from a random pairing of a male and a female (assuming hatcheries have enough brood to spawn 1 female/1 male). Through random chance, a desirable female might be paired with the gametes of an undesirable male. The result of this pairing reduces the fitness of desirable female's progeny. In nature, the undesirable male would not have had much of a chance to reproduce and his set of undesirable genes would might be eliminated from the gene pool, thus increasing the overall health of the genepool. Through the hatchery process, the elimination of less-desirable fish at spawning does not occur and healthy fish cannot select healthy mates through random pairing of spawners.
When the juveniles hatch, the close quarters of hatcheries may cause an increase in cortisol levels which may cause juvenile hatchery fish to become more voracious feeders (Garner et al, 2010). The size at release is often larger amongst hatchery fish, and they are potentially more aggressive, driving their wild counterparts out of the optimal feeding areas. The increase in total juvenile numbers may evoke whats called a type III functional response where predators are attracted by the density of the prey (juvenile steelhead), increasing the overall predation on the population. Furthermore, hatchery fish that return to rivers are less successful in spawning, however if they do successfully manage to mate, their less-desirable genes are passed on and reduce the genetic fitness of the population. Furthermore, they take up spawning area and may dig up the redds of wild fish if they should spawn later than a wild pair.
I think hatcheries have their place in several instances:
a) to support a fish an artificial fish population in an otherwise unhealthy rivers such as the Capilano where the Cleveland Dam has blocked access to spawning grounds and stopped cut off the supply of gravel to the lower reaches. Some salmon and steelhead still successfully spawn in-river, but there is little spawning habitat available due to the unfortunate placement of the Cleveland Dam.
b) provide a productive harvest fishery. People like eating fish, those people pay taxes too, so enhancing some rivers to provide this opportunity is fair and provides opportunity for businesses such as tackle shops, guiding, river-side accommodation etc.
I believe the best (only?) way to restore a wild population of fish is through habitat enhancement. This could take the form of installing fish-friendly culverts on coho tributaries, to ensuring the presence of proper gravel in spawning beds, to protecting riparian zones, marshes, estuaries, making sure there's structure in a stream, even stream fertilization.
Damn, that was great Matt! I learned a lot from that. Another question though...do hatcheries spawn predominantly HATCHERY fish as broodstock, or do they take wild ones to spawn with?
-
Damn, that was great Matt! I learned a lot from that. Another question though...do hatcheries spawn predominantly HATCHERY fish as broodstock, or do they take wild ones to spawn with?
Well when it comes to salmon, there really is no such thing anymore as purely wild salmon on rivers with a hatchery program. On the river were I do broodstock we take both marked(wild) and unmarked(hatchery) fish. As for steelhead it is pretty much unmarked fish for broodstock.
-
Thanks for the educated replies.
Seems like a damned if you do and damned if you don't situtation.
What if they released the hatchery fish at younger age?
http://abcnews.go.com/Technology/story?id=99347&page=1 (http://abcnews.go.com/Technology/story?id=99347&page=1)
http://www.sciencedaily.com/releases/2009/06/090610091224.htm (http://www.sciencedaily.com/releases/2009/06/090610091224.htm)
BN
-
It's funny you say that because they want the coho to stay longer. We release half of our stock at the usual time and the other half about 4 months later.
-
Thanks for the educated replies.
Seems like a damned if you do and damned if you don't situtation.
What if they released the hatchery fish at younger age?
http://abcnews.go.com/Technology/story?id=99347&page=1 (http://abcnews.go.com/Technology/story?id=99347&page=1)
http://www.sciencedaily.com/releases/2009/06/090610091224.htm (http://www.sciencedaily.com/releases/2009/06/090610091224.htm)
BN
Releasing them earlier might have some effect on the phenotype (just wiki this, too tired from studying to explain :) ), but it wouldnt' deal with the issue the lack of sexual selection in the male/female pairings so the genotype (genetic makeup) would likely be inferior to a wild fish.
I don't know if Id say we're damned if we do, damned if we don't as I think habitat enhancement, while slower to have an effect, is ultimately the best answer that I've been exposed to.
-
--I'd say.. it all depends.... there is a counter argument and scientific evidence given for each statement.
--Check out the yearly studies on the Columbia river systems and tribs... you will find a set of Biologists who's research is funded by several native bands who have hatcheries to allow for commercial fishing... the will give an extensive list of technical fixes to issues such as Gene pool etc.
--Some would argue Gene pool can be diversified via hatchery and that undesirable characteristics will quickly be naturally eliminated.
--I believe there needs to be strict protocols before hatchery supplement is even considered and if implemented that habitat restoration and fishing regulation including both commercial and recreational must also be a part of an overall recovery plan.
-
--I'd say.. it all depends.... there is a counter argument and scientific evidence given for each statement.
--Check out the yearly studies on the Columbia river systems and tribs... you will find a set of Biologists who's research is funded by several native bands who have hatcheries to allow for commercial fishing... the will give an extensive list of technical fixes to issues such as Gene pool etc.
--Some would argue Gene pool can be diversified via hatchery and that undesirable characteristics will quickly be naturally eliminated.
--I believe there needs to be strict protocols before hatchery supplement is even considered and if implemented that habitat restoration and fishing regulation including both commercial and recreational must also be a part of an overall recovery plan.
Consider the sexual selection process and the natural selection that takes place during the juvenile stage as filters in the gene pool. You cannot remove those filters and not have a negative effect on the gene pool.
If you can find one peer-reviewed journal article that concludes that the hatchery process can *increase* the health of a genepool, I will eat the still-beating heart of the next hatchery coho I catch, on video and admit on camera that I know nothing of genetics. I will stand by my word.
-
If you can find one peer-reviewed journal article that concludes that the hatchery process can *increase* the health of a genepool, I will eat the still-beating heart of the next hatchery coho I catch, on video and admit on camera that I know nothing of genetics. I will stand by my word.
I love a challenge. Consider the gauntlet picked up.
P.S. You said peer reviewed...you did not say the peers had to agree. ;D
-
--Check out Andre Talbot -- discussion at the Columbia River Inter-Tribal Fish commission-- roughfly quoted from my notes " using hatchery fish to increase genetic variance has value and natural selection will work to weed out less fit in the population"
--When I say .. some would argue... that does not mean I think we should do it... Just means I think it warrents further credible investigation without predjudice.
--Not saying we would want to do it but think about it.. if you have only 20 fish returning to a stream, they are limited in their selection and may not make the same selection of a mate given more choices.. thus if we dumped in a few fish from the columbia into the thompson into the same stream where 20 return.. the fish may not make the same choice of mate. The isolated population has a limited gene pool from which to choose a mate they now have more choices of mates which come from a divergent population.
-
--Check out Andre Talbot -- discussion at the Columbia River Inter-Tribal Fish commission-- roughfly quoted from my notes " using hatchery fish to increase genetic variance has value and natural selection will work to weed out less fit in the population"
--When I say .. some would argue... that does not mean I think we should do it... Just means I think it warrents further credible investigation without predjudice.
--Not saying we would want to do it but think about it.. if you have only 20 fish returning to a stream, they are limited in their selection and may not make the same selection of a mate given more choices.. thus if we dumped in a few fish from the columbia into the thompson into the same stream where 20 return.. the fish may not make the same choice of mate. The isolated population has a limited gene pool from which to choose a mate they now have more choices of mates which come from a divergent population.
I found that too, but it is not peer reviewed...still looking for that ellusive abstract.
-
I found that too, but it is not peer reviewed...still looking for that ellusive abstract.
I got a lead on a peer reviewed article published in "Fisheries" magazine. I just need to secure a copy! MMMMM... hatchery coho heart.
-
Consider the sexual selection process and the natural selection that takes place during the juvenile stage as filters in the gene pool. You cannot remove those filters and not have a negative effect on the gene pool.
So does the "natural selection process" only apply to the hatchery fish when first cultivated and then no longer apply when that fish mates and the cycle repeats (naturally) over the years. Would the new "diversity" not add to the local gene pool and if unfit be removed and back the way it was?
Would the hatchery program on the great lakes not be a "benefit" to the gene pool as they have now diversified to freshwater as opposed to just salt?
Also, the vedder which has incredible amounts of fish is doing quite well clearly due to the hatchery. Now, would these fish all become dumb and die off with out the hatchery... unlikely I would think. I'm sure the offspring will figure it out and do fine.
Fish stocks are declining and if it was not for hatchery's I'm sure we would be in trouble.... In the states it has brought back nearly wiped out runs....
Altering the gene pool will very well have an effect, but negative... could also be positive I would think.
-
I love a challenge. Consider the gauntlet picked up.
P.S. You said peer reviewed...you did not say the peers had to agree. ;D
as in peer-reviewed journal, such as Fisheries Ecology and Management.
(http://www.wiley.com/bw/journal.asp?ref=0969-997X&site=1/url)So does the "natural selection process" only apply to the hatchery fish when first cultivated and then no longer apply when that fish mates and the cycle repeats (naturally) over the years. Would the new "diversity" not add to the local gene pool and if unfit be removed and back the way it was?
Would the hatchery program on the great lakes not be a "benefit" to the gene pool as they have now diversified to freshwater as opposed to just salt?
Also, the vedder which has incredible amounts of fish is doing quite well clearly due to the hatchery. Now, would these fish all become dumb and die off with out the hatchery... unlikely I would think. I'm sure the offspring will figure it out and do fine.
Fish stocks are declining and if it was not for hatchery's I'm sure we would be in trouble.... In the states it has brought back nearly wiped out runs....
Altering the gene pool will very well have an effect, but negative... could also be positive I would think.
While the influx of new genes may, in some cases, benefit a gene pool, the removal of mate-selection is detrimental to its health, no question about it.
My understanding of hatcheries in the states is that they pump out huge numbers of fish. Would that avoid collapse if the hatchery was removed? I'm not sure, but I have my doubts. In that case, I wouldn't say that that's "bringing back" a run of fish. That's conjecture of course, so not eating any salmon hearts if I'm wrong on that one, but I wouldn't mind being proven wrong if anyone can find evidence to the contrary. It would be brilliant if salmonid runs could be restored with hatchery programmes alone, as it would be a faster solution than habitat restoration.
The Vedder has a tonne of coho, yes, are the genetics good? The reason Vedder coho return in numbers that dwarf any other lower mainland system is because of the huge number of juveniles released into the system. Even if the odds for those hatchery juveniles are lower than wild fish, some are bound to return by chance. I've been fortunate enough to have had the opportunity to fish coho in truly wild rivers and Vedder coho don't compare in average size and degree of sexual dimorphism (ie: kype development in males) displayed. Vedder coho are certainly abundant, but are they as healthy as, say, a truly wild Kimsquit River coho? I doubt it.
-
double post.
-
Thanks for the educated replies.
Seems like a damned if you do and damned if you don't situtation.
What if they released the hatchery fish at younger age?
http://abcnews.go.com/Technology/story?id=99347&page=1 (http://abcnews.go.com/Technology/story?id=99347&page=1)
http://www.sciencedaily.com/releases/2009/06/090610091224.htm (http://www.sciencedaily.com/releases/2009/06/090610091224.htm)
great articles, thanks for sharing.
BN
-
So does the "natural selection process" only apply to the hatchery fish when first cultivated and then no longer apply when that fish mates and the cycle repeats (naturally) over the years. Would the new "diversity" not add to the local gene pool and if unfit be removed and back the way it was?
Would the hatchery program on the great lakes not be a "benefit" to the gene pool as they have now diversified to freshwater as opposed to just salt?
Also, the vedder which has incredible amounts of fish is doing quite well clearly due to the hatchery. Now, would these fish all become dumb and die off with out the hatchery... unlikely I would think. I'm sure the offspring will figure it out and do fine.
Fish stocks are declining and if it was not for hatchery's I'm sure we would be in trouble.... In the states it has brought back nearly wiped out runs....
Altering the gene pool will very well have an effect, but negative... could also be positive I would think.
I am not so sure the Great Lakes can be used as an example of "improving a gene pool" as there were no Pacific Salmon in the Great Lakes before the hatcheries so there was no gene pool to diversify. The argument mentioned above is that when the gene pool of a system is near collapse (less than 10 fish let's say) then the introduction of a few hundred hatchery fish, while genetically inferior perhaps, still adds diversity to the pool where the fish pairing up are pairing with a limited number of possible mates (5-10). This is only true if the brood stock the hatchery fish came from was different (came from a different system) than the stock from which the 10 wild fish came. Usually, the hatchery tries to keep brood stock local, taking brood from the local pool, as this increases the compatibility of the offspring to the conditions of the system. If the hatchery fish came from the same stock as the 10 wild fish, then there is probably not much added diversity as there would probably be more diversity between the 10 wild fish than between the hundreds of hatchery introduced fish.
-
I am not so sure the Great Lakes can be used as an example of "improving a gene pool" as there were no Pacific Salmon in the Great Lakes before the hatcheries so there was no gene pool to diversify. The argument mentioned above is that when the gene pool of a system is near collapse (less than 10 fish let's say) then the introduction of a few hundred hatchery fish, while genetically inferior perhaps, still adds diversity to the pool where the fish pairing up are pairing with a limited number of possible mates (5-10). This is only true if the brood stock the hatchery fish came from was different (came from a different system) than the stock from which the 10 wild fish came. Usually, the hatchery tries to keep brood stock local, taking brood from the local pool, as this increases the compatibility of the offspring to the conditions of the system. If the hatchery fish came from the same stock as the 10 wild fish, then there is probably not much added diversity as there would probably be more diversity between the 10 wild fish than between the hundreds of hatchery introduced fish.
Let me understand this... Before the great lakes had no spwaning salmon, now they do.... sounds like an improvement to me as they have just moved from oceans to freshwater which shows their ability to adapt and "improve" from a hatchery start of life. Albeit in a whole and not directly related to existing rivers with hatchery's.
From my understanding the gene pool is created from exposer to the environment and each individual fish will have a slightly different exposer to different things which gives each one it's own new makeup. The more fish that have different exposer should add to the pool.
Yes the coho in the vedder aren't the best and biggest, however being all the snaggers and such out there it could be considered a not so good quality and was removed via "natural selection"... I'm just throwing that one out :D
As far as the Kimsquit River coho... Stick the river near a major city like Vancouver and see how fast those "Superior quality's" get removed and put on a BBQ ;). They are probably more lucky they haven't had major pressure to reduce the gene pool to low numbers or change it to adapt to the new environment.
The problem most salmon face is over fishing which reduces the gene pool. As some of the rivers that have been over fished have now made better comebacks I would assume due to the hatchery adding more fish to become experienced.
Quality's we might like in a salmon may not be good for the pool... A runty, ugly coho may not be kept over a nice big one and even though the bigger and better might appear better in makeup could also be quite detrimental to the species in a urban environment.
These are however just my thoughts...
-
Doja, you're arguing that a a hatchery is required on the Vedder due to the quantity harvested. No one would argue that wild production could sustain that harvest. A river can only support so many fish.
You're correct in the overall idea that exposure to the environment leads to changes in the genepool, but the mechanism you propose isn't the way it happens. Salmonids produce many offspring, the offspring produced will all have slightly different genetic makeup. Some genetic make ups will survive better than others. For instance, a particularly wary salmon will likely evade predators, and a salmon with lighter colouration (lets make him white) than normal may be easier to spot for predators. In this example, the wary salmon has a better chance of surviving to adulthood and spawning than the easy-to-see white salmon. The wary salmon's offspring receive their parent's wariness. The white salmon got eaten by a seal, and he didn't get a chance to pass on the unfortunate white gene to any offspring.
Similarly, in the wild, a salmon must find a mate. Females must compete for the best spot to make a redd, and males must compete with other males for the best females occupying the best redds. What happens next is similar to what happens in all animals... the most successful females get paired with the most successful males and they spawn on the most desirable redds. Their offspring will have several advantages (ie: the best genes from their parents, and the best redds to hatch in), and have a better chance of spawning compared to their cohorts.
The hatchery process is less selective- a random male spawner is milked and his milt is mixed with a random female's eggs and they all rear in the same environment.
I don't mean to rag on hatcheries, they certainly are needed on rivers such as the Vedder to sustain a huge harvest or rivers where natural spawning habitat has been ruined (ie: putting a dam below spawning grounds), just the offspring from a hatchery will not be as genetically fit as their wild cousins.
-
Let me understand this... Before the great lakes had no spwaning salmon, now they do.... sounds like an improvement to me as they have just moved from oceans to freshwater which shows their ability to adapt and "improve" from a hatchery start of life. Albeit in a whole and not directly related to existing rivers with hatchery's.
I never said that the fact that you can now catch Coho and Chinook in the Great Lakes was not an improvement. I am sure there are fisherman that fish the Great Lake that would say it is an improvement. I am saying that the introduction of hatchery fish into the Great Lakes was not an improvement to the gene pool (the original topic of the discussion) as there was no gene pool of Pacific Salmon in the the Great Lakes to improve.
I am also not convinced that the fact that these Pacific Salmon can live in the freshwater of the Great Lakes is an "improvement" in their genes over their Pacific cousins or that it shows "their ability to adapt and 'improve' from a hatchery start of life", as all salmon can live in freshwater (they are hatched and reared there). The chinook and coho in the Great Lakes just do not need to adapt to the salt water of the oceans like their Pacific cousins do in their smolt stage, they simply move from the river to the lake without adapting. I am not so sure this is an "improvement," but it is damn good for the salmon guides in lake Eerie.
-
Really good information in this thread. I worked in a hatchery when I was younger and really didn't understand the possible ramifications of what we were doing. In my eyes, more fish in the river was a good thing, but clearly that is not always the case. Unfortunately, for those that like to retain the fish they catch, it seems like the best answer in most cases is to protect the remaining wild stock through catch & release and then work on improving the habitat. Sadly, that type of big picture thinking rarely catches on. :(
-
I do not want to wade into this topic too deeply but I though of this article when I read this thread. It does a good job of highlighting just one of the evolutionary consequences of raising salmon under hatchery conditions. Published in Science in 2003. I have the full PDF if anyone would like to read it (e-mail jordanabannerman @ gmail . com).
Rapid Evolution of Egg Size in Captive Salmon
Daniel D. Heath, John W. Heath, Colleen A. Bryden, Rachel M. Johnson and Charles W. Fox
Captive breeding and release programs, widely used to supplement populations of declining species, minimize juvenile mortality to achieve rapid population growth. However, raising animals in benign environments may promote traits that are adaptive in captivity but maladaptive in nature. In chinook salmon, hatchery rearing relaxes natural selection favoring large eggs, allowing fecundity selection to drive exceptionally rapid evolution of small eggs. Trends toward small eggs are also evident in natural populations heavily supplemented by hatcheries, but not in minimally supplemented populations. Unintentional selection in captivity can lead to rapid changes in critical life-history traits that may reduce the success of supplementation or reintroduction programs.
Cheers,
Jordan
-
There has been so much negative banter about the " Gene Pool " and how it is going to be the demise of our wild stocks. I would suggest that everyone take a hard look at the decline of all of our wild stocks and decide if we should cease production of hatchery fish. The Thompson River is a perfect example of a system in rapid decline and the answer is to close it until it rebuilds. Good luck. In a number of systems that have had hatchery production of Steelhead curtailed there are now very few fish. Our interior trout fishery has improved over the years due to hatchery production. Do you really want to
jeopardize that fishery by closing hatcheries?
We all would like to go back to the good old days when wild production could sustain our fisheries, but those days are long gone. Funding is not available for any large habitat projects and probably won't be in the future. DFO has just taken a 58 million dollar cut and you will most likely see a decline of hatchery produced fish in the future.
-
There has been so much negative banter about the " Gene Pool " and how it is going to be the demise of our wild stocks. I would suggest that everyone take a hard look at the decline of all of our wild stocks and decide if we should cease production of hatchery fish. The Thompson River is a perfect example of a system in rapid decline and the answer is to close it until it rebuilds. Good luck. In a number of systems that have had hatchery production of Steelhead curtailed there are now very few fish. Our interior trout fishery has improved over the years due to hatchery production. Do you really want to
jeopardize that fishery by closing hatcheries?
We all would like to go back to the good old days when wild production could sustain our fisheries, but those days are long gone. Funding is not available for any large habitat projects and probably won't be in the future. DFO has just taken a 58 million dollar cut and you will most likely see a decline of hatchery produced fish in the future.
No one would deny that "fisheries" benefit from hatcheries. That is their purpose...to provide a catch and kill fishery. Closing hatcheries is no guarantee that wild stocks will be able to rebuild in the absence of the added competition with the hatchery stock. This must also come with habitat restoration, enhancements as well. Closing the hatchery is not the solution if that is all that is done, since the wild stocks will only continue to decline. If a hatchery program was deemed necessary in the first place, wild stocks must have been in decline to begin with, and unless the original causes of that decline are reversed (the original cause of the decline was obviously not the hatchery), then removal of the hatchery will do nothing to halt the decline.
-
--Interior hatchery stock is primarily for lakes that did not have natural populations. The lakes were highly productive and the introduced fish having little competition thrived in many of them.
--The move is toward triploids, as they cannot reproduce they do not loose energy for spawn and if not caught and kept can grow for several years.
--Much of the USA hatchery fish, especially on the Columbia are a result of court actions and promises made by the power and water authorities to replace fish stocks lost due to loss of rearing and spawning habitat due to the many Columbia system dams.
--Every one here is presenting excellent points on pro and con. The pro and con change with each system or situation that you want to use hatchery stock in, thus it is difficult to argue.
--The hatchery stock program can be modified for the intended purpose and in many cases will not be helpful for recovery.
--Kokanee lakes in USA where they want large volumes of fish for catch and keep will be much different than a hatchery intended to reintroduce steelhead to a small stream that does not now have a viable sustainable natural population.
--We interfere at every stage in the cycle... we can see what is going on in a hatchery.. it is more difficult to see what is going on in the open ocean or even get accurate by-catch information...
--Every by-catch steelhead is a reduction in the natural selection... it is just more obvious when we-select the brood stock
--In some instances milt from more than one male are mixed with eggs from the same female, this happens in nature as well as the paired male chases off a potential suitor another male will sneak in for a bit of mischief.
--There are technical fixes to mitigate hatchery issues raised.. I doubt all are fool proof thus we have to used caution, however I would not want to rule out hatchery assistance in a recovery program as one of the potential tools.