Montana Fish, Wildlife and Parks has finished its annual survey of bull trout reproduction in the Flathead basin, with results below last year's in all three major drainages.

Between Sept. 29 and Oct. 30, field crews surveyed for bull trout redds, or spawning beds, in stream index sections that have been monitored for years. The index sections represent a portion of the overall bull trout spawning run.

According to fisheries biologist Tom Weaver, redd counts were about average for the last decade in the Middle and North Forks of the Flathead river system, where Flathead Lake bull trout spawn.

Counts were below average in the Swan Lake drainage and in the South Fork Flathead River drainage, where Hungry Horse Reservoir bull trout spawn.

This was the 30th year for index counts in the Flathead Lake drainages.

There were 187 redds in eight stream index sections in both the North and Middle Fork drainages, below last year's count of 225.

The North Fork count of 85 redds in four streams was well below average for the last decade. No redds were detected in Coal Creek, for years one of the weakest spawning streams.

In the 28th year of surveys in the Swan Lake drainage, there were 366 redds counted in four streams, below last year's count of 395 and considerably below counts that have numbered from 400 to 521 every year for the last decade.

State biologists have been closely monitoring the Swan Lake bull trout population ever since lake trout, a competing species, were detected in the lake.

Lake trout have been reproducing for several years in the drainage, and if their numbers continue to grow, impacts on the bull trout population are likely.

In the 17th year of surveys in the South Fork drainage upstream from Hungry Horse Reservoir, the count of 66 redds in four streams was below last year's count of 74 and well below the average counts for the last decade.

Surveys in Bob Marshall Wilderness tributaries to the South Fork, carried out every few years, were not conducted this year.

Reporter Jim Mann may be reached at 758-4407 or by e-mail at jmann@dailyinterlake.com