Sterilized Trout Catch On

To Inland Empire Fly Fishing Club members, the growing interest in filling many of the state’s lakes and private ponds with sterilized trout vindicates a dream they had 20 years ago.

They believed they could create monster trout by sterilizing fingerlings, thus enabling the fish to live long lives without undergoing the debilitating rigors of spawning cycles.

They persuaded Fish and Wildlife Department officials to permit them to surgically remove gonads from thousands of rainbow fingerlings at the Spokane hatchery. The fish then were released into lakes.

When gonads regenerated in most of the fish, the club members turned to Dr. Gary Thorgaard, a Washington State University geneticist, for development of a method to produce sterilized fish by heat-treating eggs.

Just about the time the system showed promise, the department, without explanation, ended its cooperation with the club.

Now, however, the department not only has become a believer in fish sterilization. It is voluntarily - even enthusiastically - releasing sterilized trout in several lakes, including Dry Falls, a “selective gear” lake southwest of Coulee City. And it will stock Quail Lake with sterile rainbows after the fly fishing-only, no-kill lake is rehabilitated later this year.

In addition, the department has resumed cooperating with the fly fishing club by planting sterilized rainbows in Amber Lake. Last year, the club paid nearly $2,500 to have 5,000 sterilized rainbows released into the lake.

The sterilized fish should be about 12 to 13 inches long by the time this year’s season opens April 25, past club president Boyd Matson said. Their adipose fins were clipped before they were planted. Under new regulations, all trout in the lake with clipped adipose fins will have to be released.

The club has will pay to have another 5,000 sterilized trout planted in the lake this year.

Columbia Basin fisheries biologist Jeff Korth said 2,000 sterilized rainbows were released into Dry Falls Lake last fall. Later this season, he said, 11,000 more will be planted.

Numerous Washington waters are candidates to receive sterile trout, including Pass Lake and Rocky Ford Creek, both fly fishing-only waters. Effective May 1, regulations for those sites will require fishers to release all trout they hook.

Pass Lake long has been a favorite of fly fishers who want to catch big rainbows and browns. The department probably will rehabilitate Rocky Ford Creek before considering releasing sterile trout into it.

Numerous owners of lakes and ponds now charge $100 to $200 a day to catch huge sterilized trout, and several private fishing clubs regularly buy sterilized fish for lakes they own or lease. Private fishing operations are so popular with affluent anglers that the fishers sometimes line up to pay high fees.

Interest in sterilized trout has risen so dramatically that Troutlodge, Inc., which operates several hatcheries in Washington, now produces 750,000 to 1 million sterilized trout a year for the state and operators of private lakes and ponds.

Operations manager Jim Barfoot said that Troutlodge, maybe the largest producer of sterilized fish in North America, now exports several million sterile eggs a year.

The fish have excellent growth potential, he said. Some strains the company produces can weigh 18 to 20 pounds after a few years.

Barfoot said Troutlodge experimented with heat treatment to sterilize eggs, but now uses the pressures-hock method because results are more consistent than heat treatment.

The firm raises sterile fish to the size its customers want. Sizes range from fry weighing less than an ounce to lunkers in the 12- to 15-pound range. It delivers the fish in special trucks.

Until they’re a foot or so long, sterile fish don’t grow faster than standard hatchery trout. In fact, they may not grow quite as fast. However, they soon outgrow hatchery trout and continue growing for several years. Most hatchery trout, on the other hand, die after their third year. Therefore, few are more than 20 inches long.

It’s unlikely that sterile trout will be released into multiple-species waters, where there are no tackle restrictions and anglers are permitted to kill more than one trout a day. In most cases, they’ll be released into “selective gear” and fly fishing-only lakes.

They’re too valuable to be caught only once. That’s why the commission is requiring all adipose-fin-clipped trout hooked at Amber Lake be released.

Problems almost certainly will arise as fish-hungry anglers learn that there are outsized trout in such lakes as Amber, Dry Falls and Quail. Wherever there are big fish, there will be poachers.

Despite foreseeable problems, it looks as though there will be more and more lakes where anglers can expect to hook bragging-size trout.

, DataTimes MEMO: You can contact Fenton Roskelley by voice mail at 459-5577, extension 3814.

The following fields overflowed: CREDIT = Fenton Roskelley The Spokesman-Review