Colorado Parks and Wildlife aquatic biologist Ben Swigle stocked seven-inch Tiger Muskie fish into Gross Reservoir on a sunny Tuesday at the 440-surface acre reservoir sitting at 7,282 feet in southwest Boulder County.
A non-native fish, and one that is a hybrid, the Tiger Muskie plays a small, albeit, important role in the management of fisheries across Colorado.
“They are considered a silent predator to help us control undesirable species that are present in some of our lakes and reservoirs,” said Senior Aquatic Biologist Jeff Spohn. These undesirable species compete with sportfish such as Rainbow Trout and Brown Trout for resources and can reduce the productivity of a body of water.
The undesirable species in Gross Reservoir are White Suckers, a fish that if left uncontrolled could dominate the water. The same holds true across many Colorado waters where predatory fish are stocked to keep the ecosystem in balance.
Swigle has seen great results in balancing the species of the fish at Gross Reservoir by using Tiger Muskie.
“Ten years ago we had 78 percent sucker biomass in the reservoir, but we started stocking Tiger Muskies and Brown Trout and that has gone down to around 35 percent,” Swigle said.
The nice thing about Tiger Muskie is they are easier to control.
A Tiger Muskie is a Northern Pike and Muskellunge (muskie) hybrid. It has irregular, dark-colored vertical markings on a light background and long snout. They differ from a Northern Pike in the fact that, since they are a hybrid, they are sterile and can’t reproduce. Northern Pike, which too were once stocked in Colorado as a predatory fish and have also been illegally introduced into other bodies of water, have the capability to take over a fishery and decimate trout populations due to their voracious appetite and ability to naturally reproduce.
This year, 15,000 Tiger Muskies were stocked statewide into 29 different bodies of water. These fish are stocked into sportfish reservoirs to control White and Longnose Sucker populations, and are not stocked into streams or rivers. Those sucker species are native to the South Platte Basin, however, their numbers often grow exponentially in stillwater reservoirs when left without a predator.
Tiger Muskies are stocked in late summer in Colorado. Some of the bodies of water in the vicinity of the Front Range where they are stocked include Evergreen Reservoir, Antero Reservoir, Pinewood Reservoir and Big Creek along with Gross Reservoir.
The number of Tiger Muskies stocked pales in comparison to other fish species stocked across the state, where if you look at Walleye and Rainbow Trout production, those are stocked in the multi-millions per species. This year alone, trout produced by CPW hatcheries and grown to ten inches or “catchable size”, numbers approximately three million.
The Wray Fish Hatchery is responsible for raising Colorado’s Tiger Muskie population before they are stocked. CPW acquires Tiger Muskie fry (juveniles) through trades with Nebraska. We supply Nebraska with species they need (commonly Walleye) and return ask for Tiger Muskie.
“The beauty of it is that we can control their numbers, so if they do too good of a job we can always go and take them out and don’t have to worry about them sustaining a population,” Spohn said.
Swigle and the technicians assisting with Tuesday’s annual survey of the reservoir found a Tiger Muskie that was stocked last year at seven inches in length had grown to 18-inches in length, so they do grow quickly.
Fishery Management & Surveys
Colorado Parks and Wildlife (CPW) is the lead agency responsible for fisheries management of public waters in the State of Colorado. The primary tool that guides fish management is the lake and stream survey. These surveys primarily consist of periodic monitoring of fish populations. During the survey process fish are collected using a variety of gears and returned to the water after the necessary biological data is recorded. Visit the CPW website to find a survey of a water near you.
The demand of Tiger Muskie fishing is on the lower end of the angler preference spectrum, however, there is a following that targets them.
Where one of the parents of the Tiger Muskie, the Muskellunge, are native in the midwest, they are a highly sought after fish. People travel from all over to catch muskie in their native range. Wisconsin, Minnesota, Michigan and Canada are hotbeds for muskie fishing.
The Tiger Muskie can test to the skills of anglers, but the powerful and very large fish are sure fun to catch. The state record for the biggest Tiger Muskie caught in Colorado is 40 pounds, two ounces, caught by Jason Potter at Quincy Reservoir in Arapahoe County in 1994.
The bag and possession limit for Tiger Muskie in Colorado is one fish and it has to be at least 36 inches long to keep.
Written by Jason Clay. Clay is a public information officer for the Colorado Parks and Wildlife northeast region.