By KEITH RIDLER
The Associated Press
2/9/01 8:13 PM

The (Bend) Bulletin

SUNRIVER, Ore.(AP) -- Central Oregon anglers are getting ever nearer the trophy rainbow trout which swims elusively through their dreams. Not because of a new lure, but because of a new fish:

"Cranebows."

The Oregon Department of Fish and Wildlife's ambitious cranebow program, now in its fourth year, cleared a big hurdle last month when biologists spawned the first batch of cranebow brood stock at the Fall River Hatchery.

"This will be an important step, if it's successful, as far as meeting our angling goals," said Steve Marx, a Bend-based biologist with the ODFW.

The brood stock cranebows average 5 pounds with some up to 8 pounds. They are part of the ODFW's long-range plan to replace current hatchery stocks which are not native to the area and are failing to meet the department's expectations with trout that originated in the area.

The hope is that the larger, more robust cranebows will eventually be used to stock all Central Oregon waters where stocking takes place. The cranebow program also meets an ODFW directive to use fish stocks indigenous to the area, which, it is believed, will be more successful at surviving in the wild than the non-indigenous species currently being stocked.

The result is more and bigger fish for anglers -- the goal of the cranebow program.

Cranebows are trout that originated from wild trout in Crane Prairie Reservoir southwest of Bend.

Beginning in 1997, the ODFW has each January through April snowmobiled to remote locations to capture wild rainbow trout that were making spawning runs up tributaries of Crane Prairie Reservoir. From those trout, biologists collected 50,000 eggs in 1998, and 185,000 in the next two years. More eggs are currently being collected from wild trout to provide a supply of wild genes to the captive program.

While most of the eggs taken in previous years were eventually raised into fish that were released into either Crane Prairie, Little Lava Lake, Big Lava Lake, Big Cultus Lake or the Deschutes River, some were retained at the hatchery for brood stock.

In January, those fish became the first captive cranebows to spawn another generation, significantly boosting the number of eggs the ODFW has to work with. If those eggs prove viable in producing another generation of cranebows, the ODFW will be closer to replacing currently used hatchery fish with cranebows.

"Depending on results, it will be a fairly important step in meeting allocations if we move into production scale," said Marx. "Basically, we're using hundreds of thousands of fingerlings (to stock Central Oregon waters). To get to that, it's going to require this captive brood stock to support that program."

The ODFW has already cleared some big hurdles in pursuing its goal of producing cranebows. But, said Marx, there are more hurdles ahead.

Checked off the "to do" list is the ODFW successfully taking eggs from wild trout and then successfully raising them in hatcheries to spawning size. Future obstacles for cranebows include determining if the eggs of the brood stock are viable and can be raised to release size.

Also, the ODFW wants to find out if the cranebows, once released, will survive in the wild, and if they will come to an angler's offering with some regularity.

"Everything looks good," said Marx. "But a lot of the little wrinkles don't show up until you actually do it."

One wrinkle that showed up surfaced in the last batch of cranebow brood stock. Only about 25 percent of the females were ready to spawn, which resulted in about 70,000 eggs from 25 fish, Marx said. Biologists now have to wait for more of the cranebows to come into spawning condition.

"That's something we learned," noted Marx. "The maturation process for that captive brood may come at different times."

Another wrinkle was the unexpected appearance of bacterial kidney disease (BKD) last fall in cranebows at the Oak Springs Hatchery near Maupin.

Several hundred of the 31,000 cranebows died as a result, and biologists decided it was too risky to release the survivors in the Deschutes River or Big Cultus Lake, where the fish were destined last spring, because of the possibility of spreading the disease. Instead, the fish were released in East Lake, a contained system where the disease would not be able to spread.

At the Fall River Hatchery, biologists were so concerned with the possibility of BKD that individual groups of eggs were isolated pending the results of disease tests. Any batches of eggs found with the disease will be destroyed.

On another front, sampling last summer at Big Lava Lake found encouraging data on cranebows. A live trap resulted in the capture of 64 trout, with 22 of them (35 percent) being cranebows. Cranebows also represented 58 percent of the captured trout that exceeded 11 inches in length.

Considering that cranebows accounted for only 20 percent of the total number of rainbow trout the ODFW released into Big Lava Lake in the previous three years, the data suggests that cranebows have a better prognosis for survival and growth than the current hatchery stock.

Still, that sample was too small to consider conclusive, so more studies at Crane Prairie and other lakes are planned this summer. That information will tell biologists what hurdles lay behind and ahead.

"We've come a long way," said ODFW biologist Ted Wise. "But we still have a long ways to go."