Lake McConaughy:The history, the fishies, the tragedy, the hopeful comeback
Lakes and Reservoirs Program Manager
Nebaska Game & Parks Commission
Back in the early 1940's a dam was completed on the Santee River in South Carolina. After the completion of that dam it was discovered that striped bass could live, survive, even successfully reproduce entirely in freshwater. That eventually spawned (pardon the pun) a wave of striped bass stocking in fresh waters across the United States. Nebraska joined the striped bass stocking fad in 1961 when a whopping total of 10 adults were stocked in Lake McConaughy. Like I said that was one of the stocking fads that have swept the country over the years and dense-headed fisheries biologists eventually learned that some habitats were not good habitats for striped bass. In other waters excellent, and popular, striped bass fisheries exist to this day.
Striped bass and hybrid striped do not thrive in any ole mud hole; that is one thing learned from stocking them in a lot of different types of waters. Striped bass especially are a cool-water species that thrive in cool, open-waters with an abundance of open-water prey fish. That is also true of the hybrid striped bass or wipers, especially big wipers. The numbers of striped bass in McConaughy may be very low right now, but we still have an excellent fishery for hybrid striped bass or wipers there and many anglers enjoy the opportunity they have to catch those trophy fish in addition to white bass, walleyes, smallmouth bass, and channel catfish at Lake McConaughy. Diverse fisheries satisfy a diverse group of anglers.
Back in the day, back before a young whipper-snapper biologist like me was around, things like kokanee salmon, coho salmon and chinook salmon were stocked in Lake McConaughy. Again you can call that dense-headed or political or whatever, but it was very much state of the science at that time. By the mid '70's a popular and nationally recognized striped bass fishery existed at Lake McConaughy, but once it was recognized that there was a problem with the prey base, stocking of an additional large predator was not a good idea. Striped bass stocking in McConaughy ceased in 1981. We have documented some natural reproduction of striped bass in Lake McConaughy, it may be very infrequent and dependent on high water levels and just the right water conditions, but there may be a striped bass or three present in McConaughy for years to come.
There is no doubt that striped bass are large predators that will eat a lot of prey. When a prey base disappears predator fish will eat whatever they can find and fit in their mouths. With the lack of gizzard shad that sometimes occurred at Lake McConaughy, you bet the striped bass ate whatever they could. All the other predator fish in the reservoir at the time did the same thing. Because of that it has been my contention, "revisionist history if you want to call it that", that the problem at McConaughy was exacerbated by a fish community that included a lot of predators including striped bass, but the real problem was an unstable prey base. It has been my contention that striped bass were the "big bad wolf" that were blamed by some anglers.
I guess this may be reciting "the party line" but I have here a 1984 research report authored by one of our fisheries biologist (whether he was one who left the state or still works in the state I will not say). That report refers to the problem at McConaughy as being one where "The system evolved from a diverse prey bass and stable sport fish population through the 1960's to a single, highly unstable prey." What that refers to is the natural aging process all reservoirs go through. New reservoirs are very productive and have a lot of flooded terrestrial vegetation that provides great habitat for a variety of species. As reservoirs age that habitat changes. That is especially true on Nebraska reservoirs with hard sandy substrates and dramatically fluctuating water levels. Open -water prey fish like gizzard shad and alewives can still thrive in that open-water, fluctuating-water-level habitat while many other species of small fish do not.
Anyhow, once that problem was recognized, striped bass stocking ceased, and efforts were undertaken to diversify the prey base in Lake McConaughy. As I mentioned previously several prey species were tried at McConaughy; threadfin shad, spottail shiners, alewives, and rainbow smelt. Alewives were one of the last ones tried and eventually proved to be most successful. Again that may have been a dense-headed move; I have said there are trade-offs with almost any decision and there is not a perfect prey fish in many situations. But again that was very much a logical, state of the science approach to the situation. Alewives will compete with and even comsume other small fish; rainbow smelt will as well. There were trade-offs made, that is how many decisions are and that is why some of them are hard to make.
Oh, I mentioned the aging process reservoirs go through--that is one reason reservoirs like McConaughy used to have some great fishing for species like crappies and yellow perch. In fact I have pictures of my grandparents, aunts, uncles, and dad with lots of McConaughy crappies and perch back in those days when the reservoir had that habitat and produced that fishery. No amount of stocking can overcome habitat deficiencies and again aging irrigation reservoirs with a lack of shallow water cover, lack of protected shallow areas, and fluctuating water levels are not ideal for producing species like crappies and yellow perch. Right now with all the vegetation growth that has occurred with the low water levels at McConaughy, IF we ever see water levels back to where that terrestrial vegetation is flooded, we will likely see a temporary "boom" in fish like northern pike, yellow perch, and maybe even crappies. Oh and that will occur whether we stock those fish or not if habitat conditions are right.
Speaking of stocking, (jumping all the way from sandhill lakes to McConaughy to Harlan County Reservoir here
), yes, water levels did come up at Harlan last year. There are still northern pike in Harlan and this spring those fish will move into the newly flooded vegetation and find excellent habitat conditions for pike spawning. There will again be a "pulse" in the pike population and pike fishing at Harlan in the years to come. Just in case those pike do not know how to reproduce on their own, we plan to stock some pike in Harlan this year, probaby in May, since habitat conditions are more favorable for that species right now. No, we cannot have hatchery ponds of pike or other species sitting around just in case a reservoir like Harlan fills with water and provides an opportunity where habitat conditions are once again favorable.
Now, back to McConaughy, let's talk trout. Unfortunately the same aging process has very much impacted, ended, the trout fishery at Lake McConaughy, not the "big bad wolf" striped bass. Trout need both cold and well-oxygenated water to survive. Some reservoirs and lakes are deep enough to provide cool enough water with enough oxygen to support trout. McConaughy was that type of reservoir for a number of years. The problem with a man-made reservoir, especially one with a lot of agriculture in its watershed and annual water draw-downs, is that habitat changes resulting in the loss of that cool oxygenated water and those changes can occur relatively fast. This problem was recognized at McConaughy years ago; quoting from an April 1976 article, Old Before its Time
, in NEBRASKAland magazine (that is the company line, I know
), "In the long run, Lake McConaughy's trout will lose their battle for survival to eutrophication [that is the big word that describes the aging process all lakes and reservoirs go through], whether in 5 years or 50." We continued to stock trout in Lake McConaghy until 2000; I think we rode that horse about as far as it would go.
How much trout water do you suppose there is in Lake McConaughy in August now? How many trout are still able to run up North Platte valley streams like Pumpkin Creek to spawn now?
Lastly, believe me I understand how politics and social concerns enter into the decision-making process. Want me to list those opinions of mine that have been over-ruled by politics or some other concern? Wildlife and fisheries management in this country is left, as much as possible, to trained scientists. Any good fisheries biologist better learn real quick that managing a fishery includes managing the users, the human dimension, as much, even more, than the aquatic habitat and aquatic organisms. It is not a perfect system, but I would defend it as the best fish & wildlife management system the world has ever seen. Of course any system is only as good as the people we have working in it, but again I am confident that over the years we have had some great people, some of the best, working in this system in Nebraska! Would I agree with every decision that was made? Heck no, but we all know "hindsight is always 20/20"
We will continue to do our best to protect and enhance the states fisheries resources and provide a variety of fishing opportunities for a variety of anglers. We need the support of every angler in the state in that mission.
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