ARLINGTON — For the second year in a row, sections of the Batten Kill where habitat restoration efforts have been made are showing an increase in the trout population by increments of up to 7-1/2 times, according to Vermont Fish & Wildlife Department fisheries biologist Ken Cox.

While Cox said the results were still preliminary within the overall scope of the trout population study, the count from this year and last show that yearling trout, which includes brook and brown trout measuring less than 10 inches, increased in the areas where habitat had been restored to about 75 fish per 500 feet of river for the last two years. That count is up from about 10 fish per 500 feet in 2005 and 2006.

Young-of-the-year trout in the same areas increased to about 75 trout per 500 feet in the last two years from about 35 in the two years before them.

Measuring the biomass of trout, the weight of all size classes less than 18 inches combined, Cox found it came to about 30 pounds per acre for 2007 and 2008, up from about 10 pounds per acre for 2005 and 2006.

The department measured the trout population in 2005 and 2006 to provide some control numbers against which the population could be measured after habitat restoration measures were put into place.

Cox said the trout population was measured in the Batten Kill according to two habitat classifications. First are pools, sections where the water is deeper, slower and cooler that were created by the habitat restoration efforts. Second are riffles, sections where the river is faster and shallower.

Through the trout population measuring project, the state has counted fish in several areas where the habitat was restored and several areas where fish populations have been counted since 1998.

Within those parameters, Cox pointed out there were some indicators that the habitat restoration efforts are having a positive effect.

The increase in yearling population is important because it's a population of trout that has been very low since the mid-1990s.

Cox said the population growth found in the pools was not mirrored in the riffle habitats of the Batten Kill or the two control sections where habitat restoration has not yet reached.

The state plans to continue to count the trout population for another two years. Until the end of the study, Cox said he was reluctant to draw any definitive conclusions but said the indicators were positive to date.

"I would hope the findings hold up over the next two years," Cox said. "That will provide some serious information for the town and other interested parties like the Batten Kill Watershed Alliance on how the river can be managed and protected and improved."

Cynthia Browning, executive director of the Batten Kill Watershed Alliance, said the state's results were exciting.

"Now that we have not just a story but what are almost proven restoration efforts, we can reach out to other funding sources and continue our efforts to take care of the rest of the river and then the tributaries," she said.

With the design and construction assistance of the state and the Green Mountain National Forest and financial contributors like The Orvis Company, the alliance has been organizing a project to restore the trout population through the development of habitat for the past three years.

Starting with a quarter mile of the Batten Kill each in the first two years and increasing to a half mile this year, workers have been adding woody vegetation, primarily the "root wads" at the bottom of large trees, to provide areas of shaded cover near the river's banks.

Other structures, nicknamed tables, have been built using donated pieces of slate. The tables, two side pieces and a top, help slow the river's current and provide a feeding area for trout.

Browning said the encouraging results of the latest trout population survey have renewed her determination to restore the habitat along a full mile of the Batten Kill in 2009.

Cox said the Fish & Wildlife Department would review its findings after 2010, the last year scheduled for a trout population survey.

A recommendation will then be made to the state and other groups dedicated to natural resource preservation, which may help determine how widely used the habitat restoration efforts being implemented in the Batten Kill will be in the future.

The Fish & Wildlife Department is attempting to restore the trout population without stocking the Batten Kill.

Despite the progress made, it remains a catch-and-release river for anglers.

Contact Patrick McArdle at patrick.mcardle@rutlandherald.com.