October 24, 2003 11:00 pm

By Dick Mason

Observer Staff Writer

Steelhead are fish of mystery.

Scientists are not precisely sure why steelhead can navigate so accurately to the Pacific Ocean and back. In addition, the places many steelhead travel to in the Pacific are a bit of a mystery since relatively few are caught at sea by commercial fisherman.

Still much is known, including the fact that Northeast Oregon has another promising fall steelhead run.

The number of steelhead returning to this region is above the average for the past 10 years. The number is off from a year ago, but this is not surprising since the region had a bumper return last fall.

"It's down a little from last year, but last year was phenomenal,'' said Mike Flesher of the Oregon Department of Fish and Wildlife.

Counts at Bonneville Dam indicate that as of Oct. 16, a total of 354,000 steelhead had passed over it. This is down from the 475,000 steelhead that had passed over Bonneville a year ago as of Oct. 16. The 10-year average is 276,000.

Fish counts at Lower Granite Dam, the last dam steelhead pass before entering the Grande Ronde River, tell a similar story. A total of 157,000 steelhead had passed over it as of Oct. 16. This is 30,000 less than last year but 70,000 more than the 10-year average of 87,000.

Lower Granite Dam count data also indicate that over the past month steelhead have been coming over at an impressive rate. From Sept. 10 to Oct. 16, more than 1,000 steelhead passed over the dam each day. The peak was on Oct. 9, when 6,779 steelhead went over the dam.

"Steelhead have been flying over the dam,'' Flesher said.

Another positive sign is the catch rate. Oregon Department of Fish and Wildlife surveys indicates that from September to mid-October anglers were catching one steelhead for every 11 hours fished in the Troy area. During the same period a year ago anglers landed one steelhead every 16 hours.

Steelhead angling will get even better once fall rains start coming and river levels swell. Steelhead travel more when river flows pick up.

"Any increase in flow brings fish out of the Snake River,'' Flesher said.

The best illustration of how low the water flow is at Troy, which is one of the most popular sites for steelhead fishing in Northeast Oregon. The flow rate there is 600 cubic feet per second, down significantly from the 50-year average for this time of year of 800 cfs.

Steelhead season started in Northeast Oregon on Sept. 1 and will run through April 15. The bag limit is three hatchery-raised steelhead per day. Hatchery-raised steelhead are those that have had their adipose fins clipped.

About half of the steelhead coming back are two-ocean fish — fish that spent two years in the Pacific Ocean before beginning their trip back to Northeast Oregon.

Two-ocean steelhead weigh 6-12 pounds and one-ocean steelhead weigh 3-6 pounds.