Field reports: Missouri River brown trout grow in size

FISHING – Fly fishers have been reporting standout fishing for bigger brown trout on the Missouri River upstream from Great Falls this year, and there’s proof they weren’t telling fish tales.

This year’s trout population was bigger in size and slightly lower in abundance than the past two years, said Montana Fish, Wildlife and Parks fisheries biologist Grant Grisak. That’s typical as the population reaches maximum size.

Fisheries surveys this year indicate rainbow and brown trout numbers remain above the long-term average in the Missouri River between Holter Dam and the town of Cascade.

Surveys this fall estimated 5,194 rainbow trout greater than 10 inches long per mile near the town of Craig on the Missouri. That is above the long-term average of 3,174 rainbows per mile and continues a trend of above-average numbers over the past three years: 6,034 per mile in 2011 and 7,312 in 2012.

“This year, 87 percent of the rainbow trout in the Craig section were 15 inches long or greater, and 35 percent was 18 inches or longer,” Grisak said.

Next year, the population should return to normal levels. Brown trout in the Craig section at 10 inches long and greater were estimated at 745 per mile. The long-term average is 578.

In the Cascade section, near the town of Cascade, the estimate for rainbow trout 10 inches long and greater was 2.260. The long-term average is 1,551 per mile.

Brown trout in the Cascade section 10 inches long and greater were estimated at 447 per mile. The long-term average is 387.

Brown trout populations are sampled in the spring and rainbow populations are sampled in the fall.

Protections considered for Montana grayling

FISHING – Federal wildlife officials said Monday they will review the status of arctic grayling in Montana to decide if the fish species should receive greater protection on the upper Missouri River.

The review stems from a legal settlement with wildlife advocates who sued to force the U.S. Fish and Wildlife Service to take action on hundreds of species. An earlier review, in 2010, found grayling warranted protections, but no action was taken because officials said other species took priority.

The Missouri River system upstream of Great Falls holds the only North American arctic grayling population outside Canada and Alaska. The fish are related to trout and known for a colorful, sail-like dorsal fin.

An initial decision on whether to grant threatened or endangered status is due by Sept. 30, 2014. If federal officials propose more protections, a final decision would come a year later.

Despite the 2010 decision that more protections were warranted, Fish and Wildlife Service biologist James Boyd said a similar outcome is not guaranteed this time around.

Wildlife officials have been working with private ranchers to reduce impacts on grayling habitat from excessive grazing in the Big Hole River system, a tributary of the Missouri. Boyd said that’s led to new fencing to keep cattle away from rivers and streams.

“There’s been a lot of work done since then and the species was highlighted through that process,” Boyd said.