Hatchery


Recently the CBC reported on a story regarding hatchery/wild fish.

Several of our volunteers have asked questions about this study and so we thought it would be good to give a response. We have a huge volunteer effort in Powell River that supports our hatchery. This effort has provided quality results  for 34 years.  Thank you for that support!

We have taken some time to review the article and the study. After you have read the above story please read below for our  comments.
Our Response:

“Salmonid Enhancement Program facilities only enhance wild salmon—no domesticated stocks have ever been introduced and no evidence of any in-hatchery selection (domestication) that is outside the normal range of naturally produced salmon populations has ever been detected. While fish reared in a hatchery may appear slightly different (e.g., in body size, shape, or color, or in some behaviors) because of artificial rearing conditions, they are genetically the same as their naturally produced cousins, and these superficial differences fade away as the fish adapt to oceanic conditions” (MacKinlay and Howard 2002).MacKinlaySalmonHatcheriesinCanada
If a wild salmon’s genetic expressions can be altered in a single generation of hatchery rearing, it’s safe to assume a hatchery salmon spawning in a wild environment would do the same.
The Parkdale Hatchery on The Hood River in Oregon has been enhancing steelhead since 1991. It would be difficult to say with any degree of confidence that the steelhead they used as a “wild” baseline is in fact a purebred Wild fish, with no hatchery influence. The fact that they were able to find “wild” steelhead in a system that has been enhanced for a quarter century in the first place is a testament to the ability of the hatchery salmon to re associate with the wild population.
Jason Seals, ODFW assistant district fish biologist on the Parkdale Hood River Hatchery’s Brood Facility:

“There’s certainly more hatchery steelhead that return than wild ones,” Seals said. “We haven’t figured out exactly what we are going to do with the program in the future.” He went on to explain that the plan is to use the seasonal weirs to continue to analyze and collect wild fish for brood stock and remove hatchery fish to keep populations balanced.

http://www.hoodrivernews.com/news/2010/jul/26/gone-in-july-fish-facility-to-be-removed-with/

Contrary to what Blouin’s study implies, the Hood’s hatchery fish are out performing the wild population according to the quote above. This appears to be in direct contrast to Michael S. Blouin’s single generation gene expression hypothesis, which asserts the genetic domestication of the hatchery raised fish or Blouin’s assertion”maybe its an energy thing ?”
It’s equally interesting that steelhead were used for the experiment. Steelhead are repeat spawners. Even if the broodstock were screened genetically for “wild” genes, Steelhead require 1-5 years of freshwater rearing time, and in fact the fry used in this experiment were yearlings. This is significant because it exponentially intensifies the pressure, stress, overcrowding, summer heat, and other suggested negative effects the study projects on the hatchery AND wild environment. Most salmon are raised in a hatchery environment for less than half of the time the steelhead in the experiment were, during far less stressful time frames and conditions. This study does not represent common hatchery practice.
The sample sizes were notably small for such a “significant” study. Only 12 pairs of steelhead were used for each wild-wild and hatchery-hatchery RNA-seq, and 5 pairs respectively for the cross pairing. It appears reckless to make such lofty assertions based off of data from: 1 hatchery, 1 small group of fish, 1 species and a yearling time frame. There are countless variables within a hatchery system that can affect salmon health, and the record of these variables are absent from the study. Where are the limits for stocking density, dissolved oxygen levels, temperature, present biotics… etc? With no baseline data of the conditions the steelhead endured, it’s impossible to make a blanket assumption over all hatcheries, as conditions vary greatly between them.
With populations of salmon in serious danger, not unlike the Hood River once was with the dam installation, hatcheries have been an effective tool in bearing the man made challenges placed upon the species. There are some groups who would like to view the salmon’s challenges through rose colored glasses and “let nature figure it out”. This romantic view is not compatible with our industrialized consumer landscape and fails to confront the reality of man’s impact on the wild. The group from Oregon State has been making these same anti hatchery claims for over a decade. The purpose of collecting scientific data should be to form opinions that are grounded in fact. This study seems to be content with taking worse case scenarios and making blanket suggestions.

 

 

 

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