Tiger Muskies Stocked in Upper North Crow Reservoir

LARAMIE – There is a new predator in Upper North Crow Reservoir, and if you are a patient and determined angler you just might catch one.

The Wyoming Game and Fish Department stocked 650 tiger muskies into Upper North Crow Reservoir earlier this week as a biological control to reduce the numbers of longnose suckers and white suckers.

“These fish were stocked to control a very abundant sucker population that has had negative impacts on stocked game fish,” said Steve Gale, fish biologist in the Laramie Region. North Crow Reservoir has been stocked annually with rainbow trout and grayling since 2006. Splake, which sometimes feed on white suckers, were stocked annually from 1999 through 2014 to help reduce the abundance of suckers. But the naturally occurring suckers proved to be a formidable competitor. “The suckers compete with the game fish for food and other resources. As a result, growth of rainbow trout and grayling has been slow and fishing has been very slow for anglers,” Gale said.

In addition to splake stocking, fisheries managers tried to reduce the numbers of suckers by trap netting from 2006 through 2010, but saw little impact on the population. “The sucker population continues to increase and if left unchecked will continue to impact fish stocking and angler success and satisfaction,” Gale said. “Although longnose and white suckers are native to the drainage, their overall abundance and distribution throughout the state is secure, so we felt comfortable attempting to reduce their population in Upper North Crow Reservoir to improve angler success.”

The tiger muskellunge (muskie for short) is a carnivorous fish, and is the sterile hybrid offspring of the true muskellunge (Esox masquinongy) and the northern pike (Esox lucius). Tiger muskies have been used in other waters in Wyoming to control overpopulated or undesirable fish species.

Trout stocking will be discontinued at Upper North Crow Reservoir to force the tiger muskie to feed on the suckers. About 1,000 tiger muskies will also be stocked in 2016 and 2017. “As the sucker population decreases we will phase out the tiger muskies and restock game fish,” Gale said. That could be several years down the road as it will take at least two or three years before the tiger muskies become effective predators and then biologists want them to have a few more years to make an impact on the sucker population.

But trout anglers shouldn’t fret; you can still fish for trout nearby at Crystal and Granite reservoirs in Curt Gowdy State Park. These reservoirs will continue to be stocked with trout each year.

Because they are sterile, the tiger muskie population will eventually die off in Upper North Crow Reservoir. Stocking will resume once the tiger muskie population drops.

Until then, anglers only have to wait for the tiger muskies to grow. While they are small now – only six to eight inches – the tiger muskies will grow quickly and should reach legal harvestable size of 30 inches within a few years.

Fish managers say tiger muskies are difficult to catch but will prove to be an exciting challenge for the determined angler. “These will make a nice trophy fish when they reach the large sizes we are expecting them to obtain at Upper North Crow Reservoir,” Gale said.