October 04, 2010
Despite a large minimum size limit and very restrictive harvest limits, Turtle Creek Reservoir has changed from a bass fishing hotspot to being more conducive to catching catfish. Here's what happened. (May 2010)
Good-sized largemouths, like this one, are few and far between these days at Turtle Creek Reservoir.
Photo by Ron Sinfelt.
Typically, if one were perusing through the fishing regulations book and came across a lake with a very restrictive harvest limit for largemouth bass of 20 inches and one fish per day, it might lead to the assumption that this fishery was being protected or developed as a trophy location. That would be a good assumption much of the time. Unfortunately, it's not the case with Turtle Creek Reservoir. Not only is the lake not a top bass fishing location, the largemouth fishery there has virtually collapsed.
In the past, Turtle Creek Reservoir in Sullivan County was a great destination for largemouth fishing. In fact, pressure from largemouth anglers was so great that the restrictive regulations mentioned above, along with boating limits were initiated to protect the fishery from over-harvest. Anglers traveled from miles around to seek out the good numbers of bass in the impoundment. Regrettably, the lake and bass fishery have undergone a profound about-face since then, much to the chagrin of biologists and anglers alike.
Turtle Creek Reservoir is 1,550 acres and was constructed as a cooling lake for the Merom Generating Station, which is owned by Hoosier Energy. The lake began flooding in January of 1980 and was stocked with fish soon thereafter. Originally the lake was stocked with basic species such as bluegills, channel catfish, and largemouth bass.
As with many newly impounded lakes, the bass population really took off. New lake phenomenon results in plenty of forage, no competition for food, and typically fertile conditions. This allows bass to grow at accelerated rates and quickly reach quality size. It wasn't long before angling pressure was so high for bass, the Indiana Department of Natural Resources (DNR) and Hoosier Energy decided to limit access and implement harvest restrictions.
Originally there was an 18-inch size limit put on largemouth bass. Later it was raised to a 20-inch limit and anglers could only keep one fish per day. Whether or not the harvest restrictions worked was never researched, according to DNR fisheries biologist Dave Kittaka. "Catch-and-release bass fishing was so popular, I'm not sure it made a difference."
Whether or not it worked really doesn't matter now, because in the early 1990s, the bass fishery completely nose-dived. Hoosier Energy has an exemption for thermal discharge limits; therefore, they are required to provide biological monitoring data for the lake. Surveys show that bass recruitment was very poor, so subsequently, numbers of bass declined rapidly. Along with the bass fishery collapse, the lake lost almost all of its rooted aquatic vegetation, both submergent and emergent. This obviously dramatically affected the success of any good largemouth bass reproduction.
Questions as to why this happened still remain somewhat unanswered. Some folks believe the bass died off due to thermal loading from increased production from the generating station. Others believe it is due to environmental reasons. Good arguments exist on both sides of the debate.
Michalene Reilly is the manager of Environmental Services for Hoosier Energy and has worked at Turtle Creek Reservoir for the last 20 years. While Reilly admits there's no denying that thermal loading can be somewhat detrimental to bass, she believes other reasons are more attributable to the decline. She also makes a valid point in reminding everyone that the whole reason the lake was constructed in the first place was to provide a water source for energy production, so people can't really have ill feelings over thermal output.
"I believe the decline is due to the natural transition of a manmade lake. You never know how fisheries will develop over time," she said.
She said the lake started off really good for bass, but over time the lake has matured in a way that is not optimal for bass. Instead, it has become a superb catfish lake.
Concurrent with the decline of the bass, the vegetation started to die as well. Reilly said the last place for the vegetation to die was close to the discharge area, which is the hottest part of the lake. She said this is a great indication that water quality issues are more to blame than is thermal loading.
Some 65 percent of the lake's watershed is farm ground. With normal farming practices, chemical usage and erosion, drainage into the lake creates unfavorable water quality. No one is pointing fingers at farmers or blaming them for doing anything wrong, but the reality is normal farming practices do result in a downside to the watershed.
Losing the rooted vegetation has been one of the biggest problems. The loss of vegetation directly affects the ability of spawned bass to find hiding places. Even if the bass have good reproduction, the fry cannot survive if they can't hide from predators long enough to grow out of eatable size.
Additionally, there has been an abundance of algae growth at the lake. Because bass rely partially on sight to locate forage, the algae creates yet another problem for the fishery. Catfish on the other hand, feed more by smell, so water clarity is of no consequence.
Channel catfish were originally stocked at the lake and have always done well. Additionally, flatheads have also been introduced to the lake, not through stocking, but most probably when makeup water has been pulled from the Wabash River. According to Reilly, it's not uncommon to catch flatheads in the 35-pound range and she knows of fish up 65 pounds being caught.
The channel catfish are reproducing naturally in the lake and have literally exploded which, along with the flatheads, also creates competition for food with the bass.
"Channel catfish have reached a level that the DNR has removed the 10-fish bag limit for an unlimited bag limit for channel catfish," biologist Kittaka said.
Hoosier Energy is working to improve bass fishing at the lake, but the success thus far has been marginal; the outlook for the future is not overly encouraging. They have been stocking fingerling largemouths there for several years. Initially, they were stocking about 25,000 to 30,000 fish per year. For the past two years, they have increased that number enormously up to approximately 130,000 fish per year.
Reilly said there are some bass in the 2- and 3-year-old classes have survived. They ar
e also seeing a small amount of natural reproduction. "It's going to be a while before we see significant improvement."
Along with the stocking program, steps are being taken to improve the water-quality issues. Most of the work being done involves working with land management practices in the surrounding watershed and doing some bank stabilization projects. "Turtle Creek is an elevated impoundment and as a result, has tremendous wind driven wave action. Any time you can limit shoreline erosion, it is going to be of benefit," said Kittaka.
What will be the long-term effect of this work? Neither Kittaka nor Reilly believe the work will make a huge difference for the future. "To date, little to no improvement has been demonstrated," said Kittaka. While Reilly is a little more optimistic than Kittaka, she has little encouragement for bass anglers. "This lake will never be anything more than a catfish lake. However, we do think we can offer some bass angling again in the future."
There are still some bass in the lake and some are even quite large. However, going there strictly to fish for bass is not encouraged. Most anglers will find the experience pretty disappointing. However, if catfish is of interest, this lake both now and in the future looks to be one of the top catfish destinations in the area.
More information on Turtle Creek Reservoir is available at www.hepn.com/turtlecreek.asp. Additional fishing questions may be directed to the hunting and fishing information line, which may be reached by calling (812) 356-4744. Fisheries biologist Dave Kittaka may be reached at the Avoca State Fish Hatchery by calling (812) 279-1215.