OUT Column June 28, 2009
DOW works to increase kokanee in Blue Mesa
This writer has spent many a winter’s day on the ice at Blue Mesa Reservoir in the company of more-experienced anglers hooking, landing and releasing lake trout bigger than a full-grown collie.
n more temperate weather, those same anglers motored around, dropping heavy maribou jigs and pulling from the reservoir’s depths lake trout often tipping the scales at 40 pounds and more.
We all knew those lake trout were that big primarily due to the millions of kokanee salmon on which the lakers fed, a resource renewed annually by the Division of Wildlife.
But now, with kokanee numbers dropping faster than your 401(k), a concerned Division of Wildlife is proposing a bailout that’s sure to garner its share of cheers and jeers.
As with all fisheries management, it’s a complicated problem.
The concern on both sides of the issue isn’t new. State aquatic biologists have long been aware something was happening at Blue Mesa.
The unease grew as a series of creel surveys showed a precipitous drop in the kokanee catch, from 175,000 in 1993 to just 30,000 in 2008.
A similar drop has been seen in the rainbow catch, from about 74,000 in 1998 to only about 10,000 in 2008.
It’s not for lack of trying. Each year, the DOW stocks about 2.9-million kokanee fry in Blue Mesa. When they mature three or four years later, the surviving salmon make their way up the Gunnison and East rivers to Roaring Judy hatchery.
There, hatchery workers spawn the fish, raising the eggs and producing enough tiny salmon to stock Blue Mesa and other reservoirs around the state.
But many of those small salmon end up as appetizers, and this year for the first time the DOW augmented the 2.9-million Roaring Judy fish with another 400,000 fry from other waters around the state.
In 1994, the DOW estimated that the kokanee population at Blue Mesa approached 1 million.
It now is estimated to be about 200,000.
There likely are several factors contributing to the kokanee decline, including several years of low water (which concentrates the salmon, making them easier prey) plus the illegal introduction several years ago of yellow perch.
Although small in size, a perch has a lake trout-sized appetite and anglers have reported catching perch filled with kokanee fry. Perch also eat plankton, the main food source for young kokanee.
But apparently the main problem is lake trout, especially the big ones that elude all but the most-dedicated anglers.
To these anglers, catching a 25-pound lake trout isn’t much cause for celebration. That’s saved for those fish like the state record 50-pound, 3.5-ounce leviathan caught two years ago by Don Walker of Florence.
Studies show that as lake trout grow they increasingly rely on kokanee salmon. Kokanee make up about 10 percent of a 17-inch lake trout’s diet but that increases to about 80 percent between 24 and 35 inches. Once longer than 35 inches, a lake trout exists almost solely on kokanee salmon, according to the study.
“If you want to get a 40-inch lake trout and maintain it on an annual basis, it needs about 50 pounds of fish,” said Greg Gerlich, DOW state aquatics manager.
But if the kokanee population crashes, as it did a few years ago at Granby, the lake trout population crashes, too.
Which brings us to the current proposal of removing small- to medium-sized lakers from Blue Mesa while leaving bigger fish.
“We’re trying to do everything we can to restore our kokanee numbers,” DOW aquatic biologist Dan Brauch explained. “The work we’ve done to this point hasn’t included a removal component. We’re concerned that we’re going to see the collapse of the kokanee fishery if we don’t do something additional.”
A move liberalizing bag and possession limits on lake trout hasn’t worked. A survey last year showed anglers released half of the approximately 8,600 lake trout they caught.
“In an environment like Blue Mesa Reservoir where lake trout reproduction is significant, angler harvest of lake trout will help the DOW maintain the balance between lake trout and kokanee populations,” said Southwest Region aquatics biologist John Alves . “If anglers keep the fish they catch the DOW probably wouldn’t need to remove fish.”
Will this salmon rescue plan work?
While lake trout anglers can be fanatic, kokanee anglers are equally so. And there simply are more of the latter.
According to DOW figures, 40 percent of anglers at Blue Mesa are there specifically to fish for salmon, 15 percent for rainbow trout and 8 percent aiming for lake trout.
It’s an economic win, too. The business of kokanee salmon is estimated at $29 million annually to the state’s economy, including more than $5 million for Gunnison County.
Lake trout fillets, anyone?