McNeely Lake, at 52 acres, is the largest lake in the city of Louisville. As part of a larger park system, it provides local residents with fishing, boating, and hiking opportunities. However, the lake itself has been plagued by many problems in the last decade. Overfishing, algae overgrowth, loss of certain fish species, and lack of spawning habitat, have all taken their tolls on this lake. By addressing these problems in a scientific manner, I believe that this lake can be restored to the excellent fishery that it used to be.

Simply due to the fact that this lake is located next to such a major population center, the amount of anglers that take fish from this lake puts an extreme amount of pressure on it. The commonly held belief is that if only fish larger than a certain size are taken, that smaller fish will be allowed to grow to a harvestable size. But this train of thought is changing. A 2008 study by the University of Toronto showed that by releasing larger fish, the amount of fish a lake is able to produce is increased. Not only do larger fish spawn more successfully and in larger broods, but the selective pressure on smaller fish helps the lake to keep producing larger and larger fish.

In the spring and summer, McNeely becomes inundated with both filamentous and blue-green algae (Cyanobacteria). Not only does this make fishing difficult, it does not provide a food source for the fish, it makes the lake unsightly, and causes oxygen depletion. By making use of native aquatic plants, such as Elodea canadensis (American Waterweed) and Nymphaea odorata (Water Lily), both the nutrients that the algae require, and the sunlight penetrating the water, will be reduced. Subsequently, the massive algae blooms will be reduced. Both these plants also provide excellent habitat for numerous types of aquatic invertebrates, which in turn act as forage for juvenile fish.

As I have fished McNeely since the late 80's, I have noticed an unfortunate drop in the species of fish to be caught. Fish such as the Bullhead catfish, Warmouth bass, and even White crappie are rare to nonexistent. A reintroduction of these fish in numbers large enough for sustainable populations should be considered. One of the possible reasons for the decline of these fish, besides overfishing, is lack of suitable prey items. A controversial eradication of the lake's shad population in the 90's corresponded (but may or may not have caused) with the decline of these three species. In any case, providing the lake with artificial spawning habitats for the prey of these fish would undoubtedly benefit the populations. Introduction of forage fish should be considered. A native Cyprinid , such as the fathead minnow (Pimephales promelas ), would be an excellent candidate. As would the Golden shiner (Notemigonus crysoleucas ). Both are tolerant of warm, turbid waters, and reproduce in large numbers.

McNeely has a fair amount of spawning habitat for its game fish, but it could be greatly improved. For prized fish such as the largemouth bass, which prefer to make circular nests in gravel or sand in one to four feet of water, artificial nesting sites could be created. Simply the addition of gravel or sand to certain areas of the lake (corresponding with the above requirements) would be of great benefit. White crappie would certainly make use of the American Waterweed, as they lay their eggs on aquatic plants. Bullhead catfish breed in a similar fashion, requiring aquatic plants. Warmouths' are a little pickier, requiring a submerged structure in which to build a circular nest similar to the Largemouth bass. But with better spawning habitat comes a more successful fishery.

By the addition of native plants to combat algae, the introduction of viable forage fish, the enhancement of habitat, and the reintroduction of extirpated fish species, I believe that McNeely Lake could be restored to the excellent recreational fishery that it once was.

I'm certainly no expert, and it may be different in your neck of the woods, but my experience with Elodea is that it can get out of control very quickly. I certainly would not add it to any body of water. It spreads like wild fire, and will grow in fairly deep water. It'll take over entire areas in no time. Compared to other pond plants it will grow in fairly deep water so it does not stay neatly contained to a shore line. It can make both boating and fishing very difficult.

But that's just my opinion. Wait for confirmation from an expert. Plus I freely admit that I hate Elodea with extreme prejudice.

JHAP - this counts as a good post don't you agree?