Horsethief Reservoir to be Drained/Treated

Horsethief Reservoir's yellow perch population, offspring of their illegally stocked ancestors, will soon get the boot thanks to action taken by the Idaho Department of Fish and Game. The reservoir's once robust trout fishery has suffered since the illegally planted yellow perch were first spotted in Horsethief back in 2003. "We've been monitoring the perch population since then," Fish and Game Fisheries manager Dale Allen noted. "This summer, fishing for trout has been severely impacted by the stunted perch population, and the only remedy to restore Horsethief's trout fishery is to drain the reservoir down slowly after Labor Day until it is dry, and restock the reservoir with trout next spring." Fish and Game has taken this same control action twice before at Horsethief, both times because of illegally introduced perch. Fish and Game is now requesting comments and concerns about the proposed draining of Horsethief Reservoir. Correspondence related to this project should be sent to Dale Allen -Regional Fishery Manager at the Fish and Game McCall Office, 555 Deinhard Lane, 83638 or by phone at 208-634-8137. Allen expects the removal process to take about two months, concluding sometime in late October. Some perch will be salvaged and the reservoir will be opened (sometime during the process) to fish salvage by anglers. Once the reservoir is drained, biologists will apply rotenone, a fish toxicant, to any remaining waters behind the dam. In the spring of 2007, the reservoir will be restocked with catchable rainbow trout and brown trout fingerlings. Horsethief Reservoir, a Fish and Game-owned reservoir, is managed for trout fishing, and is as popular a destination for campers as it is anglers. Illegal introductions of fish, including yellow perch at Horsethief, are extremely costly to Fish and Game, and ultimately to license buyers both in terms of direct monetary costs as well as lost recreational fishing opportunities. The action is being taken because trout and yellow perch do not co-exist well in smaller reservoirs like Horsethief. "Competition for food and the high reproductive ability of yellow perch are the main problems," Allen said. "As the perch population increases, it slows trout growth, and the large numbers of small yellow perch make fishing for trout slow." Fortunately, the project should not sideline Horsethief for too long. "The reservoir will fill with next year's spring runoff and we will restock Horsethief with trout as soon as possible," Allen said. "Trout fishing should be good in 2007, and the stocked trout will grow very well in the months following restocking." For those with a passion for yellow perch, their numbers are on the rebound in Lake Cascade, just a few miles west of Horsethief. Allen and his staff expect good fall perch fishing at Cascade, and even better winter ice fishing.