ANDOVER — A public informational meeting will be held at 6:30 p.m. Wednesday, March 10, in the Andover Town Hall on a state project to eliminate invasive smallmouth bass and pumpkinseed sunfish from C Pond, the Dead Cambridge River and four tributaries.
C Pond has a surface area of 173 acres and is located between Upton and Andover in C Surplus Township in north central Oxford County.
The pond’s outlet forms the Dead Cambridge River, which flows nearly 8 miles in Upton to Umbagog Lake, which straddles the Maine-New Hampshire line.
Fisheries biologist Dave Boucher of the Maine Department of Inland Fisheries and Wildlife in Strong said Friday that the project involves killing all fish in C Pond, in 2.8 miles of the Dead Cambridge River from the pond’s outlet to a previously-built fish barrier, and in less than a mile each of the lowermost regions of the tributaries.
“Bass in C Pond are moderately abundant and increasing rapidly right now, and sunfish are exceedingly abundant,” Boucher said. “It’s very good habitat for that species. It’s so-so habitat for smallmouth, but there’s enough good habitat there for them to go crazy, and they are and they will.”
Using rotenone, an aquatic fish toxicant, the project is tentatively scheduled for the last week in September. Waters to be treated have no drinking water input.
In May or early June 2011, the reclaimed water bodies will be restocked with native minnows and wild trout from the upper reaches of the tributaries that have brookies but no bass.
Based on records of the area from the late 1950s to early 1960s, and information from the early 1900s about what fish were in Umbagog Lake, biologists will re-establish that fish type of fish community as much as possible.
“We can sort of put two and two together and come up with what we think is a native fish assemblage, and we’ll re-establish that after the pond detoxifies,” Boucher said.
To kill fish in select areas of the tributaries, biologists would set up what’s called a “drip station.” That consists of a bucket of rotenone on a hose that drips into the water and the chemical drifts downstream.
Biologists will also use backpack-like portable Indian pumps while walking down tributaries to their confluence with the Dead Cambridge River to spray rotenone in places not effectively treated by drip stations, Boucher said.
“The treatment will be restricted to the lowermost region of the tributaries because they’re pretty steep, so we know that the smallmouths haven’t got up to a certain point because they can’t ascend the steepness,” Boucher said.
“The most arduous part of that project will be treating the whole length of the Dead Cambridge River from the outlet of the pond to our fish barrier, which is about 2.8 miles.”
Bass in these affected areas came from Umgagog Lake while the sunfish either entered the same way or were illegally introduced several years ago, he said.
Boucher said C Pond, an excellent early-season sport fishery, is fished a fair amount.
“It’s not one of the more heavily used waters, but it’s still an important resource, because they are native trout, and native trout in that part of the Androscoggin River drainage are very threatened from smallmouth bass,” he said.
“So, the amount of fishing that it gets, or even the accessibility, is really secondary, because our primary mission as an agency is to protect and enhance our wild trout resources.”