Physical science along the Rogue

Physical science along the Rogue

GOLD BEACH — Blair Krohn digs the heels of his wading shoes deep into the gravel for leverage as he helps drag a 300-foot net through the Rogue River, anxiously awaiting the results of his effort.

Tourists watch from a nearby excursion jetboat while a small contingent on land peer over Krohn's shoulder to see what he and his crew have captured on the Huntley Park gravel bar shortly after sunrise.

"Everybody's into it now, pulling hard to catch all we can catch," Krohn says.

The net yields a cache of "halfpounders," immature summer steelhead unique to the Rogue. The fish are counted, measured and released as the vast net is returned to the powerboat and the whole shebang is repeated, as it has been for the last 30 years.

Krohn heads an Oregon Department of Fish and Wildlife beach-seining crew whose low-tech, high-muscle efforts help generate most of what biologists know about this year's anadromous fish runs on the Rogue, the highest producer of wild salmon and steelhead on the Oregon coast.

"It's really a unique operation," says Tom Satterthwaite, an ODFW research scientist who has worked with the seining data almost 30 years. "There's nothing like it anywhere else in Oregon."

And it's all done in open view of the public. People can gawk at the big steelhead, enormous fall chinook and other species the crew captures in its 15 net-sets every Monday, Wednesday and Friday from mid-August until November rains end the program.

"There's upwards of 20 people watching, plus those on the Mail Boats, at any given time," says Kelly Sparks, one of the four beach seiners who often are joined by volunteers. "People like it."

The seining plays out at Huntley Park, about 8 miles east of Gold Beach off Jerry's Flat Road, which hugs the Rogue's south bank. The netting is done along a rock wall at the upper end of the park's gravel bar.

The site was discovered in the early 1970s as ODFW biologists began a study of the Rogue's salmon and steelhead while the U.S. Army Corps of Engineers began building Lost Creek Lake.

Plans were to alter lake releases to benefit salmon and steelhead downstream, so the agency launched its study to learn when the various runs entered the Rogue, where they went and where they spawned.

To do that, salmon had to be captured and tagged near the Rogue mouth. Biologists chose Huntley Park for their work, where the rock wall helped create a gravely hole that fluctuates little from year to year.

By dragging the same-sized net through the hole the same way and at the same times every year, the program has helped create a great index for judging whether any given year's return of fish is above or below average.

The counts over the years have calculated the Rogue's production of threatened wild coho, indexed wild summer steelhead returns and provide the only way to judge halfpounder steelhead returns, Satterthwaite says.

The data also help biologists understand how best to spill water from Lost Creek Lake to benefit migrating fall chinook and preserve wild spring chinook, Satterthwaite says.

"There's a wealth of data pouring in from that project," Satterthwaite says. "It's a long-term data set that biologists just drool over."

Before Satterthwaite drools, however, Krohn must sweat.

The 15-foot-deep net is stacked on a powerboat bow, with one end tethered to a hook cemented into the rock face. One worker backs the boat around the face and across the Rogue, while a second crew member feeds the net into the water.

The net is dragged in an arc to shore, where it's hooked to the back of a pickup that dashes up the gravel bar to seal whatever is inside.

The group huffs and pulls the net to shore. One set last week netted more than 100 cohos, all thrashing in the shallows. Others net zilch.

Other than salmon and steelhead, this year's crews have captured three seals, hundreds of young starry flounder and several young green sturgeon.

All the counts go into Satterthwaite's database to become part of Rogue science and history.

"The more I do it, the bigger I realize it is," says Krohn, a six-year Huntley Park vet. "It's not just counting fish. It's gathering data. Important data."

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