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US Fish & Wildlife Service FieldNotes

COLEMAN NFH: ‘Reconditioning’ Program Increases Survival of Steelhead Kelt

Region 8, May 7, 2012
A small visible implant elastomer (VIE) mark, located 
just left of the fish’s eye, fluoresces under ultra violet light.
A small visible implant elastomer (VIE) mark, located just left of the fish’s eye, fluoresces under ultra violet light. - Photo Credit: n/a
Jason Fookes, a fish culturist at Coleman NFH, displays a male steelhead.
Jason Fookes, a fish culturist at Coleman NFH, displays a male steelhead. - Photo Credit: n/a

By Marc Provencher, Fish Biologist, Coleman NFH

Coleman National Fish Hatchery (NFH) released hundreds of “reconditioned” steelhead broodstock, or kelts, into the Sacramento River tributary of Battle Creek in early April. Unlike Pacific salmon which all die after spawning, steelhead are capable of spawning multiple times over the course of their life.

The steelhead is an anadromous rainbow trout that returns to freshwater to spawn after two to three years at sea; rainbow trout and steelhead are the same species.

This years’ release of 569 kelts was the 2nd largest total since the reconditioning program began, according to Kurtis Brown, production manager at Coleman National Fish Hatchery.

Additionally, 50 percent of the steelhead that were transferred to the reconditioning pond survived this year – the highest survival rate Coleman NFH has ever achieved. Reconditioned kelts provide the hatchery with increased numbers of broodstock and create additional steelhead fishing opportunities for recreational anglers.

“Kelt” is a term of Scottish-origin used to describe a post-spawn steelhead that will attempt the long return migration to the rich feeding grounds of the Pacific Ocean.

The kelt program requires a departure from the classic method of “rip-spawning,” where broodstock must be sacrificed prior to harvesting eggs. Instead the fish are air-spawned through the use of a pneumatic-hypodermic needle that allows the ripe eggs to be non-lethally removed from female steelhead. Air-spawning is a minimally invasive spawning technique that allows for increased survival of hatchery brood stock.

After spawning the steelhead are marked with a visible implant elastomer (VIE) tag that will identify them in subsequent spawning years as a returning kelt.

The VIE mark is a silicone based tag that is injected with a hypodermic needle between translucent layers of skin behind the eye. Different colors of VIE are used every year, allowing for the identification of specific years repeat spawners have been previously collected. Several fish have been observed that already have two different colored VIE marks – signifying they have returned to the hatchery three separate years.

“Marking all of the steelhead kelts with a VIE tag allows for the hatchery employees to easily identify the fish in subsequent spawning years” said Brett Galyean, deputy project leader at Coleman NFH.

Prior to release the fish are transferred to a 187,000-gallon, gravel-lined pond for a reconditioning period of at least six weeks. The kelts are fed a commercial broodstock feed and their health is continuously monitored. This is the 9th consecutive year that Coleman NFH has reconditioned steelhead kelts.

Coleman National Fish Hatchery is located in Anderson California on Battle Creek, a tributary of the Sacramento River. The hatchery is open for self-guided tours seven days a week, from 7:30 a.m. to dusk. During the months of October and November guided tours are available for groups on spawning days. For more information, or to schedule a tour please contact the hatchery at (530) 365-8622 or visit their website at http://www.fws.gov/coleman/

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Contact Info: Jon Myatt, 916-414-6474, jon_myatt@fws.gov