Beavers have lived on lakes for
hundreds, maybe thousands, of years without causing harm to the nearby
communities. In fact, beavers are considered a keystone species to an
aquatic system, meaning that other species depend on them to provide
vital wetland habitat and food sources. In addition to creating more
biodiversity for wildlife and plants, other benefits of a beaver
ecosystem are erosion abatement and flood control, and the reduction of
sedimentation in rivers and streams.
Skip Lisle, a wildlife biologist
who has spent several years beaver proofing road culverts in the
Penobscot Nation near Chesterville, spoke to a group of ecology minded
people who journeyed to that area to meet with the beaver expert (in the
summer of 2001).
The problem with beavers has been in
the expansion of homes and roads into areas normally used as beaver
habitat. The beaver population has burgeoned, but has less and less
area in which to build their dams and establish homes. Killing beavers
is not a good solution. Their presence is irrelevant if you build a
flow system such as Lisle’s Deceiver, a trapezoidal fence made
with cedar posts and six-gauge concrete reinforcing wire with 6x6 inch
squares. It is narrow at the culvert but widens upstream. While
allowing fish passage but preventing beavers from carrying branches into
the culvert, the device also silences the sound of flowing water,
reducing the beavers’ stimulus for crating dams.
Tripp Lake beaver aficionados have
long debated the plusses and minuses of beavers, with the result that
occasionally volunteers break down their dams (at the outlet) but they
are invariably rebuilt within a short time. “Busy as a beaver” is not
just a saying!