|
|
|
A relative 'Newcomer' inhabits one of Northern
Idaho's river/lake systems |
|
December 11, 2014 |
A newcomer is establishing itself in northern
Idaho. Walleye, a staple of the Midwestern
United States, have not historically been a part
of the northern Idaho landscape. They have found
their way into area waters fairly recently.
Lake Pend Oreille, well known for its kokanee,
Kamloops rainbow trout, bull trout and cutthroat
is now also home to a growing walleye
population.
Walleye were illegally introduced into the Clark
Fork River, upstream in Montana. They gradually
worked their way downstream into Idaho and were
detected in Lake Pend Oreille and the Pend
Oreille River around 2004-2006. Although
occasionally caught by anglers, substantive
catches of walleye weren't really evident until
2010.
The Idaho Department of Fish and Game (IDFG)
completed walleye surveys in 2011 and 2014 that
showed walleye are expanding. Using gill nets,
IDFG biologists sampled waters from the Clark
Fork delta, across Lake Pend Oreille, and down
the Pend Oreille River. Catches show walleye
abundance has nearly doubled in the three years
between surveys.
Walleye in the Pend Oreille system are growing
fast. Five and six pound fish are relatively
common. Although walleye are increasing, they
are still relatively low in abundance compared
to well- established populations in the
northwest such as Washington's Lake Roosevelt,
with over twice as many walleye per acre.
Walleye present a unique challenge for fishery
managers. They are often revered by anglers for
the quality of their meat and the challenging
angling experience they provide. A walleye
fishery has not been available in northern
Idaho, and biologists recognize it is something
a number of anglers desire.
Biologists recognize that new fisheries come
with risks. Walleye are predators that live
almost entirely on a diet of other fish. In Lake
Pend Oreille and the Pend Oreille River, that
means walleye may reduce the number of other
species that anglers like to catch. They may
also pose problems for some of the native fish
in the system, such as cutthroat and bull trout.
Like them or not, walleye are now a permanent
part of the northern Idaho waterscape.
Eliminating the population would not be
possible. However, because walleye were
illegally introduced and may have detrimental
impacts on some of the lake's existing
fisheries, IDFG will not encourage walleye
population growth.
IDFG has an official policy that states the
Department will not promote or enhance fisheries
for illegally introduced species. Rob Ryan,
Regional Fisheries biologist for IDFG says the
policy is intended to discourage anglers from
establishing new fisheries through illegal
introductions.
"Although illegal introductions may provide a
new fishing opportunity for some anglers, it
always comes at the expense of someone else,"
said Ryan.
Ryan acknowledges that many of Idaho's most
popular fisheries are based largely on
non-native fish, but notes not all introductions
were well thought out.
"Over the past 100 years, there have been
hundreds of introductions by government
agencies, sportsmen's groups, and private
individuals. Many of them provided benefits, but
others have caused irreparable damage."
Taking into account the lessons learned, IDFG is
now very cautious about stocking non-native fish
into new waters, and fishery managers now
implement a rigorous process to evaluate the
potential impacts and benefits of new species
introductions. |
|
|
|
Questions or comments about this
article?
Click here to e-mail! |
|
|
|
|
