Sturgeon survival the goal as departments consider changes.

Byline: INSIDE THE OUTDOORS By Mike Stahlberg The Register-Guard

If "Jurassic Park" had included a fishing adventure, it probably would have featured the white sturgeon.

Virtually unchanged from the days of the dinosaur, the sturgeon is the most resilient fish in the Pacific Northwest. Shoot, they even look invincible in their bony armor.

But new research suggests these big denizens of the deep may not be as tough as we once thought.

Which is why the Oregon and Washington departments of fish and wildlife are considering reducing anglers' opportunity to catch and release "oversize" sturgeon that congregate to spawn in the Columbia River below Bonneville Dam.

A public meeting to explain the situation was held Wednesday night in Clackamas, and the Oregon Fish and Wildlife Commission will discuss the matter Friday in Salem.

Prompting the review is research that suggests mortality among adult sturgeon is increasing - 38 carcasses were found in 2003, compared to 20 in an average year.

Of the dead sturgeon, 71 percent "either had hooks in them or hook scars," according to Pat Frazier, Columbia River program manager for the Oregon Department of Fish and Wildlife.

"That's pretty good evidence of at least a high handling rate with some of these fish," Frazier said. "It's a cause for concern for us as management agencies."

In addition, Oregon State University researchers report that 36 percent of the oversized fish they examined in the sport fishery had "multiple" hooking scars, and 13 percent had fishing leader protruding from their anal vents.

Even more worrisome is the fact that 16 percent of the females checked had reabsorbed their eggs rather than spawn.

Is egg absorption the result of stress and exhaustion associated with thrashing around on the end of a fishing line?

Researchers can't say for certain. But they do know blood taken from sport-caught sturgeon shows a direct relation between the length of time a sturgeon is fought and the amount of a stress-related chemical called cortisol found in its blood.

Sturgeon don't begin to spawn until they reach 5 feet in length, at about age 20 (white sturgeon can live to be 100 years old). But the average female reproduces only every third to fifth year, Frazier said.

OSU researchers estimate that only about 6 percent of the 2,000 mature sturgeon in the spawning area each spring are "ripe" females. Thus, the entire Columbia River sturgeon population is produced by 120 or so spawners per year.

Sturgeon anglers are allowed to keep only those fish that measure between 42 and 60 inches long. The use of a "maximum" size is intended to protect those fish that survive long enough to become part of the brood stock.

Because sturgeon were believed to be so tough, however, regulators have taken a liberal approach to "catch and release" angling. Besides, until about 12 years ago, very few anglers targeted oversized sturgeon.

Starting about 1992, however, guides began promoting the chance to catch a 6- or 8-foot-long fish weighing up to 300 pounds - even if it did have to be released. "The poor man's tarpon," they called them. And fishing pressure skyrocketed.

Now it's estimated 2,800 to 5,300 oversized sturgeon are caught and released annually in the Gorge during the summer months. The only respite afforded the sturgeon is that boat angling is not allowed May 1 through July 15 in waters between Beacon Rock and Bonneville Dam.

Washington biologists propose adding five miles to the spawning season sanctuary, by moving the angling "deadline" from Beacon Rock down to the eastern tip of Skamania Island. In addition, they want to extend the closure period by two weeks, through July 31.

They estimate those changes would reduce the "handle" of spawning-age sturgeon in that area by about 60 percent.

It's probably a good idea, lest we run the risk of sturgeon going the way of the dinosaur.

Mike Stahlberg can be reached at [e-mail].