SOCATEAN TOWNSHIP, Maine — As state fisheries biologist Tim Obrey held what looked like a television antenna above his head on Socatean Stream recently, a series of beeps from a radio receiver he also carried pierced the air.
The beeps were evidence that male brook trout, which had earlier been tagged by the biologists, had joined females for the spawning process in this remote stream in the Moosehead Lake region.
A few seconds later, Obrey was pointing out to bystanders, including Piscataquis County commissioner Eric Ward, several slivers of white on fins that fanned the stream’s gravel bottom.
Nearby, Obrey and fellow Department of Inland Fisheries & Wildlife biologists Jeff Bagley and Stephen Seeback were replicating a 1958 study to determine what changes, if any, there have been in the brook trout population since then.
Studying the fish is important because northwestern Maine is the only place on the East Coast where populations of brook trout still exist, Obrey said.
“You could draw a line from Presque Isle to Millinocket to Greenville to Rangeley — everything from that area north is the last place really in the East where we have any significant number of intact wild populations of brook trout,” he explained.
Brook trout disappeared from other areas along the East Coast because of habitat degradation from development and invasive species such as yellow and white perch, bass and northern pike, according to Obrey.
“Brook trout are very fragile,” he pointed out. “They don’t compete well with other species.”
Just as retired biologist Roger AuClair of Rockwood did in 1958 on Socatean Stream, one of the major brook trout spawning tributaries to Moosehead Lake, the biologists have constructed a weir from which they can observe, tag and monitor the movement of brookies.
Obrey said his department had not been getting enough samples previously to determine the status of the brook trout population, so they decided to build a weir.
While AuClair’s weir was made of wood, the new portable weir is made of steel pipes designed by Bagley, and the new study is a collaborative effort.
Plum Creek Timber Co. Inc. constructed and funded a road through its property so the biologists could move equipment to the stream; the Natural Resource Education Center in Greenville donated $2,000 for tagging materials; and NextEra (formerly Florida Power & Light) donated $30,000 for the weir materials.
In addition, NextEra biologists Bill Hanson and Kyle Murphy have provided their assistance. Their help is appreciated, Obrey said, because the department has only three biologists covering the Moosehead Lake region, an area bigger than some states. “Without their help, we just couldn’t do a lot of this special stuff,” Obrey said.
“Because everyone’s resources are limited, it is important to collaborate with agencies and other organizations to complete scientific research and monitoring efforts,” Henning Stabins of Plum Creek, said Tuesday. Plum Creek is interested in learning about the dynamics and health of the region’s fish populations because they are one indicator of water quality and healthy ecosystems, he said.
Hanson called his company’s collaboration with the state biologists a “win-win” for all. The biologists are managing the resource, and at the same time NextEra is basically asking permission to use the same resource to run a hydro business, he said.
“These guys in this region are doing cutting-edge stuff, in my mind. They’re using the latest technology and the best methods to really get out and look at this stuff,” Hanson said.
The weir, which will remain in place until late November, allows the biologists to do just that. Surgery is conducted by the biologists on the bellies of the trapped brook trout. Of the 350 trout trapped as of the week before last, about 30 males that are more than 14 inches long were surgically implanted with radio tags that cost about $160 each and the rest were implanted with a less expensive tag.
“We haven’t had any mortality [from the tagging process], so it’s pretty safe,” Obrey said. The radio tags have a “mortality switch” in them. If the tag doesn’t move for 24 hours, it emits a different signal, which tells biologists the fish is dead.
Fisherman who catch a radio-tagged brook trout are encouraged to release the fish back into the water because of the cost of the tag and because the tags have a battery life of almost two years, which will provide much information to the biologists over that time.
The radio tags, which can be monitored from an aircraft or on water, allow biologists to track the fish to find their spawning habitats, to look at winter mortality in the stream and to find out where their refuge is on the lake.
An antenna stretched across Socatean Stream records each tagged fish, the date it enters the stream, the time and its tag number on a computer.
AuClair, who captured about 1,200 book trout from July through November 1958, tagged the jaws of fish and had to rely on angler reports and observations.
The biologists had expected the catch to be down from the earlier study because there really weren’t any competing species then, although yellow perch had just been illegally introduced into the lake in the late 1950s.
Yellow perch are of concern to biologists because they lay hundreds of thousands of eggs compared to a few thousand laid by brook trout. “When they compete for the same food and space, their [the brook trout’s] days are numbered,” Obrey said.
Despite the establishment of the yellow perch in the lake, the biologists were pleased with their results.
“It’s actually pretty good; we’re happy with what we’re seeing,” Obrey said of the brook trout. The catch is very similar to what AuClair caught — a lot of 14- to 16-inch fish, he said.
“Because there are not a lot of brook trout left in the eastern U.S., it does sort of magnify the importance of this area, but on a sort of a smaller level,” Obrey said. It’s important to fishermen who live or visit the region to have sustainable trout fishery, the biologist said.
“This is sort of a check 50 years later, where are we now,” Obrey said.