DENVER – Fishing is fun, but the fun is no longer funded.

A $500,000 cut to the Fishing is Fun program is just one way that Colorado Parks and Wildlife is trimming expenses by $10 million. Leaders from the agency went before state senators Thursday to explain the cuts.

Senators were most concerned about a $1 million cut to the aquatic nuisance species program, which seeks to keep zebra mussels out of Colorado reservoirs. The mussels can clog pipes and render reservoirs nearly unusable.

Colorado Parks and Wildlife officers have done more than 2 million boat inspections since the zebra mussels were found in Lake Pueblo in 2008. They have found just 64 boats that had mussels attached.

“Obviously, one boat is too many because of how nasty those species are, so I’m glad you’re catching them,” said Sen. Greg Brophy, R-Wray.

Bob Broscheid, director of Colorado Parks and Wildlife, said the cut leaves $4 million in the budget, which should allow the agency to run an effective program. He’s looking to team up with other Western states to get funds to stop the spread of the species.

The agency is also cutting its budget for land purchases by $2 million, cutting its construction budget by $1 million, and eliminating some vacant jobs.

The Fishing is Fun program provides grants to towns and non-profits to build trails and piers. But the $500,000 cut will leave just $400,000 left in the program.

Like wildlife agencies around the country, Colorado is struggling to cope with a declining interest among young people in hunting and fishing.

Senators expressed concern about the cuts.

“You’ve got to capture the people when they’re young,” said Sen. Lois Tochtrop, D-Thornton. “One of the ways to do that is to teach them to hunt and fish, and that’s what the Fishing is Fun grants were doing.”

With the baby boom generation reaching retirement age, the agency has another problem. Coloradans can get free fishing licenses when they turn 65.

Even so, revenue from fishing licenses is expected to remain flat, said Steve Cassin, the agency’s budget chief.

Hunting licenses make up most of the wildlife division’s revenue, and there’s still more demand for big-game hunting licenses than there is supply, Cassin said. But in the long term, wildlife officials are worried about the graying of the hunting population.

Colorado merged its parks and wildlife divisions in 2011. At the time, the parks division was assumed to have the worst budget troubles, while the Division of Wildlife was thought to be a healthy agency, flush with revenue from out-of-state hunters.

But a deeper look at the books revealed that the wildlife agency had been overspending. Late last year, the Parks and Wildlife Commission approved a plan to cut $10 million out of the wildlife side of the budget.

Broscheid began work as the agency’s director just two months ago.

“My first order of business is to get our financial house in order,” he said.