McConaughy producing big fish in big numbers
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By BRUCE CONDELLO / For the Lincoln Journal Star
Big Mac is dead.
It’s the word on the street.
Years of subnormal snowfall in Wyoming and lack of rain in western Nebraska have sucked the life out of the Cornhusker State’s largest reservoir and one of its best fisheries.
Lake McConaughy is a puddle, devoid of hope as much as moisture.
Don’t believe it.
Currently Lake McConaughy is producing excellent numbers of fish, as well as good numbers of trophies for the Nebraska and Colorado anglers willing to make the trip to the Ogallala-area reservoir.
How is it possible? If the lake is practically dry, then surely the fishery must have dried up with it.
The answer is in the beautiful jade color of the water.
“There’s not a lake in the state that’s not fertile,” says Daryl Bauer, reservoir and lakes program manager for the Nebraska Game and Parks Commission. “And Lake McConaughy is no different.”
As Nebraska reservoirs age, they accumulate more nutrients, which produces more phytoplankton, tiny plants that form the true backbone of the food chain. The plants allow zooplankton and small fish to thrive. The quality walleye, wipers and white bass at Big Mac flourish as a result, Bauer said.
Bauer went on to explain how eutrophication, or natural aging of watershed lakes, boosts their productivity. Available nitrogen works in harmony with certain types of water chemistry to produce an ideal environment for phytoplankton.
In less fertile waters in other parts of the country, these nutrients are lacking and aging lakes take on a very clear, but also sterile, quality. Some folks even have to add fertilizer to their farm ponds to get fish to grow. Nebraska has no such problem.
Phytoplankton, now in ample supply at Big Mac, wasn’t historically present in such vast quantities.
In the 1960s and ’70s, for example, the lake was clear, with far fewer accumulated nutrients. This allowed for a two-tier fishery, with warmer water species such as walleye and white bass doing well in the upper water column and cold water species such as trout thriving in the deeper, cooler waters.
Now, the more eutrophic water isn’t suited for trout on a consistent year-round basis — but the walleye, white bass and wipers do well.
These tiny, green plants are a massive food source for zooplankton, and the tens of millions of midges found in various sizes around the lake each spring and summer. The stomachs of white bass often reveal a wad of midge larvae, which would have been far less likely when the lake was less productive.
“Lake McConaughy holds more pounds of game fish per acre of water than it used to,” Bauer explains. “This highly productive food chain allows for rapid growth of walleye and other desirable species.”
When fishing the lake a few weeks ago, my wife, my father and I waded the perimeter of Lake McConaughy.
We caught dozens of wipers from 6 pounds on up. Even more white bass, and good numbers of gorgeous 15- to 22-inch walleye were willing participants in the angling game.
We also noticed what appeared to be hundreds of thousands of small, shiny bait fish known as alewives.
The commission decided to introduce alewives in the 1980s to stabilize the prey base in the lake, Bauer said.
Gizzard shad were historically the only significant forage in the lake, and the cyclical nature of a gizzard shad populations made for a feast or famine situation. Harsh winters would kill off most of the shad, and the predators would be left with virtually nothing to eat.
Alewives, less sensitive to temperature changes than shad, have allowed a much more consistent growth of game fish.
It can make fishing tougher, because the predators have the luxury of being very selective in what they eat. If there’s a lot of food available, you have to be better at matching the hatch, like fly fisherman do.
Gizzard shad are still present, and recently have been a valuable part of the food chain as the alewives have temporarily declined, Bauer said.
One thing was very evident during our visit to Lake McConaughy: The fish are fat.
The body condition of the wipers, white bass and walleye was incredible.
The lake also is producing large numbers of impressive channel catfish. Catches of fish in the 5- 10-pound range are commonplace, and my father even caught one that might have tipped the scales at close to 20 pounds had he chosen to keep it.
Smallmouth bass also frequent the rocky areas of the lake and gorge on the alewives, reaching 2 pounds with regularity.
All of the larger fish we caught were released to be caught again by other lucky anglers. There were plenty of nice eating-size white bass and midrange walleye to keep.
Of course, Lake McConaughy still remains under threat because of the drought. Inflows to the lake remain well below average. The only reason the level has increased lately is because irrigation water hasn’t been released, thanks to ample rains in south-central Nebraska.
“It’s all about water“, Bauer said. “The lake’s fish population has already responded to the loss of about 60 percent of the lake’s water. We’ve seen periodic die offs during the heat of the summer.”
Low water volume in eutrophic lakes means more stress on fish during the heat of the summer. Bad things could still happen to Lake McConaughy.
So for now, be grateful for the 40 percent of water that still exists in the lake. Big Mac is alive and well.
Lincoln dentist Bruce Condello is an avid angler and contributor to Journal Star Outdoors.
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