Permit sought to exterminate perch

Larch Lake: Application calls for use of rotenone to kill off invasive species.

The province is targeting a small waterbody in the Larch Hills area with the hope of preventing a significant threat from spreading.

Those people who frequent the popular Larch Hills cross-country ski area may be familiar with the Larch Lake Loop, named after the little lake not too far past Cec’s Cabin.

What skiers won’t notice, for obvious reasons, is the spreading population of the lake’s non-native inhabitants, yellow perch, a voracious fish species that can drastically alter a lake’s ecosystem.

The Ministry of Forests, Lands and Natural Resources is in the process of applying for a pesticide use permit in order to treat the lake, and the adjacent Larch Hills Creek, with rotenone. Ministry spokesperson Brennan Clarke describes the chemical as “an organic-based compound fatal to fish but not amphibians,” that  has been used successfully in the management of yellow perch in nine other B.C. lakes over the past six years, including Gardom and Skmana lakes.

“An assessment by the federal Department of Fisheries and Oceans suggests that failing to deal with this small population of yellow perch would open the door for these fish to migrate into Shuswap Lake, and cause extensive damage to native species and the ecosystem as a whole,” says Clarke.

BC Wildlife Federation member Don Trethewey says in these cases the fish has been illegally introduced to the lake. This is illegal in B.C., with a penalty of up to $100,000 for first-time offenders.

Asked about the process of treating the invasive species with rotenone, Trethewey says it’s the only satisfactory way to do it.

“It doesn’t take long for them to totally over-populate a lake and become stunted, and nobody wants them then,” says Trethewey of yellow perch. “And they eat everything they can cram down  their throat, even other little perch. So they really can do a number on the ecosystem… in terms of the insects and invertebrate life in the lake.”

While the Larch Lake Loop is busy in winter, the area also sees use in summer from other recreational users.

Phil McIntyre-Paul of the Shuswap Trail Alliance says Larch Lake is important to the area, both ecologically and socially.

“It’s got recreational value with both fish there and people hiking out there, and I’ve heard folks talking about swimming out there,” says McIntyre-Paul.

McIntyre-Paul says the Larch Hills joint-user committee, formed of motorized and non-motorized user groups, have already put up gates to protect sensitive bogs in the area, and will be putting up simple pole stiles to help limit access to other sensitive areas, including Larch Lake.

Anyone wishing to provide input on the pesticide permit application, or wanting more information, may contact Andrew Klassen at 250-371-6237, by email at, or by visiting the ministry regional office in Kamloops at 1259 Dalhousie Dr.