This "thread" should bring out even more bowls of popcorn....

[Silver Creek]

Before we can agree on whether hatchery trout are the same as wild trout, we need to agree on what is a hatchery trout and what is a wild trout. My definition is based on DNA and not where the trout eggs were hatched and the young raised.

For example, Wisconsin's Wild Trout program takes the egg and sperm from wild fish, hatches them in a state hatchery, raises them in a hatchery, and then releases them back into their native river. These released fish have a higher survival rate than hatchery DNA trout released into the wild. There is a difference in the DNA that translates to a difference in behavior and performance.

We can do the opposite experiment and hatch eggs from hatchery trout in a river by using Whitlock-Vibert boxes.

http://www.fedflyfishers.org/Conserv.../EggPlant.aspx

Put fertilized eggs in the boxes and put the boxes in a river. The eggs are hatched and the fry live in the river and not in a hatchery, BUT genetically, they are hatchery fish.

So do we consider these wild fish or not. By my definition, they are not and by the definition of fisheries biologists, they are not wild. They will have a lower survival that the fry that are genetically wild.

Not only that, but if they interbreed with wild fish, the hybrid hatchery/wild offspring will have lower survival than a pure wild strain fish.

This is what the following study proved.

https://www.dartmouth.edu/~ark/image...ies/miller.pdf

So rather than use Whitlock-Vibert boxes to raise hatchery trout in rivers, they are used to hatch eggs from wild pure bred strains of threatened trout.

http://www.fs.fed.us/outdoors/nature.../Incubator.pdf

Regarding the inability to tell wild from hatchery from wild fish in a river that has had prolonged releases of hatchery trout, this is the reason that Idaho no longer releases fertile hatchery trout into rivers with a self sustaining population of wild fish.

With interbreeding of the hatchery and wild fish, the wild strain DNA is diluted and what you get are the hybridized fish. Release enough hatchery fish over successive years that interbreed and you lose the wild fish totally. You are left with a fish that is homogenized genetically and you will not be able to tell hatchery from wild because there are no more genetically pure wild fish.

The reason one cannot tell a stocker from a holdover wild fish may be because there are no pure wild fish left. That would be a sad state of affairs.

Avoidance of that situation is why Montana stopped stocking its blue ribbon trout streams 40 years ago in 1974. The article below shows how a study by a Montana fisheries biologist, Dick Vincent, proved that stocking the Madison River actually led to worse fishing.

"In 1974, Montana did something that stunned anglers across the state and the nation: It stopped stocking trout in streams and rivers that supported wild trout populations.

The move initially outraged many anglers, fishing businesses, and even some Montana Fish and Game Department staff. For decades, hatcheries had been credited with producing more and better fishing. Without stocking, many Montanans asked, what would happen to the state's famous trout waters and the businesses that relied on legions of anglers arriving from across the country each summer"

The answer, now well known, is that trout fishing improved dramatically. Once stocking was discontinued, wild trout numbers doubled, tripled, and more on many rivers."

Dick Vincent began a study by no longer stocking a section that had been stocked and by stocking a section that had not been stocked.

"After just one year, we could see that the four-mile-long Varney section was improving by no longer being stocked and that most of the improvement was in the larger fish. By the fall of 1971, wild trout numbers had increased 153 percent from the 1967-69 average, from 1,500 trout to 3,800 trout. The improvement continued every year. By 1974 the total number of wild trout larger than 10 inches was 4,700, a 213 percent increase from the stocking years.

What happened to O?Dell, the creek you began stocking?

The wild trout population began declining. The 1967-69 average had been 515 brown trout in that 1.4-mile stretch, and it dropped to 380 in 1971 and then 280 in 1972. And the big fish numbers declined as well, dropping from 63 in 1967-69 to 14 in 1972.

Were you surprised by the results?

We'd suspected that stocking was having a negative effect, but when we saw large trout numbers in the Varney section triple and trout numbers in O?Dell cut in half, well, that just blew us away."

http://fwp.mt.gov/mtoutdoors/HTML/ar...ickVincent.htm