LAKE NORMAN’S CHANGING FISHERY
North Carolina Wildlife Federation’s
Lake Norman
Fisheries Committee
Something
is going on in Lake Norman. Bass
fishermen are catching bigger bass than ever before. Delicious tasting white perch are being caught by anglers. Different forage fish in large numbers are
showing up in the lake. What is
happening to the fishery in Lake Norman and what are the prospects for the
future?
Infertility:
Trained, highly experienced fishery biologists and scientists have closely monitored the principal baitfish and gamefish species in Lake Norman throughout the years. The North Carolina Wildlife Resources Commission has used proven management practices in the stocking of striped bass to provide fishable numbers and sizes that can be supported in the lake. Appropriate regulations on all gamefish species have been applied to provide a sustainable level of fishing quality. Management practices have been used to optimize fish populations in spite of low water fertility.
Alien Invasions:
The principal baitfish species in Lake Norman have historically been threadfin and gizzard shad. Both have provided sustenance to support reasonable populations of gamefish over the years. However, other species of baitfish, such as alewives and blueback herring, have been recently introduced into the lake. Scientific surveys of the lake have shown that the total number of baitfish has not varied much over the past few years but the composition of the baitfish population has. Most recently, alewives have composed up to 30 percent of the baitfish population with threadfin shad still being the most abundant specie. The principal difference between threadfin shad and alewives is the fact that shad feed primarily on zooplankton while alewives primarily eat the eggs and young of various fish species in the lake. This appears to be causing a reduction in shad numbers. It is doubtful, however, that alewives will become the dominant prey specie in the near future due to the threadfin shad’s tremendous reproductive capacity.
In addition to alewives and blueback herring, white perch began showing up in lake surveys in 1998. Although it is impossible to determine how white perch invaded the lake, both intentional and inadvertent stocking are likely possibilities. Fishermen, particularly those pursuing striped bass, have historically visited neighboring lakes to catch live bait using cast nets. The live baitfish brought back for use in Lake Norman are often composed of a mixed bag of alewives, herring, shad, and juvenile white perch. At the end of a day of fishing, anglers have frequently discarded remaining live bait into the lake.
For whatever reasons, during the past few years, the population of white perch in Lake Norman has mushroomed. Huge numbers of perch are propagating. In a few short years, the previously significant population of white bass in the lake has been decimated, probably by white perch. White perch may have simply eaten the white bass fry and eggs and competed directly with them for the limited forage. Perch are excellent table fare and anglers are encouraged to catch and keep as many as possible. However, angling alone cannot keep the population of white perch in check. Currently, white perch offer an excellent opportunity for those anglers seeking large numbers of fish for table fare. The question now is whether the current populations can be controlled to maintain a quality new fishery. If white perch overpopulate Lake Norman in the future, they will inevitably become stunted.
Alewives and blueback herring have long been a favorite bait of striped bass anglers. No doubt, “bait bucket stocking” introduced these baitfish species into the lake in limited numbers for many years. It is likely that predation by such species as striped bass and largemouth bass has helped control their numbers over the years while permitting both threadfin and gizzard shad to continue to be the dominant baitfish species. However, a small group of striper anglers has long felt that stocking of large numbers of alewives and bluebacks into the lake would aid the fishery. In meetings with biologists from the North Carolina Wildlife Resources Commission, these anglers proposed that stocking of blueback herring or alewives into Lake Norman would improve the striper fishery by providing a hardy baitfish population that would not be prone to the periodic “die offs” which occasionally occur with threadfin shad in unusually cold winters. Although shad populations are known to recover rapidly, these anglers believe that the quality and quantity of gamefish would be improved with the introduction of non-native baitfish. The Wildlife Commission biologists argued that introduction of alewives and bluebacks could cause a number of both foreseen and unintended problems in the overall fishery.
Acting independently of the Wildlife Commission, two local striper clubs have raised funds from public events to help purchase and stock large numbers of bluebacks and alewives into Lake Norman. In just 2-3 years, alewives and, to a lesser degree, blueback herring have become abundant. Remember, threadfin and gizzard shad feed predominantly on zooplankton. On the other hand, alewives and blueback herring feed on the eggs and young of other fish species where their ranges overlap
Largemouth Bass:
Since Lake Norman was formed, largemouth bass have arguably been the most popular gamefish. Numerous bass clubs hold regular catch and release tournaments on the lake. Lake Norman has also hosted major regional bass tournaments in recent years and plans are in place to do so again in the future.
In the past few years, most area largemouth bass fishermen have seen an increase in the numbers of larger fish caught during a day of angling. Fisheries biologists surveying the bass populations are finding fewer young fish to replace the mature fish in the system. It is possible that predation by both recently introduced baitfish and white perch has resulted in reduced spawning success for largemouth bass.
In the short term, anglers will probably continue to catch numbers of adult bass. However, recent studies have shown that recruitment of young fish is declining. It remains to be seen what the long-term results of reduced recruitment will be. Considering the lake’s relative lack of fertility and habitat cover, it is possible that this could be a positive indicator. However, if spawning success of largemouth bass continues to decline, the quality of the bass fishery could eventually be compromised. Be assured that the lake will continue to be closely monitored for both numbers and quality of largemouth bass.
Crappies:
Crappie fishermen are reporting fewer of their favorite fish along with other panfish species being caught. Sampling data developed over the past several years have provided variable results. The data suggest that recruitment of crappies into the system show no particular trends at the present time. Once the 2004 and 2005 data are analyzed, the NCWRC should have a better picture of trends in panfish populations.
White Bass:
Lake Norman has historically supported a healthy population of white bass. In just a few years, the influx of non-native species has nearly destroyed the white bass fishery in Lake Norman. The vast numbers of white perch and alien baitfish, competing with the smaller populations of white bass, have sealed the demise of this once popular specie in our lake.
Striped Bass:
Striped bass are at the top of the food chain in Lake Norman. They do not propagate successfully in the lake and must be stocked annually to maintain a viable population for sport fishermen. In the past, stockings of striped bass have averaged about 162,000 per year. This number has been deemed adequate to maintain a supportable population of stripers.
Since significant numbers of alewives began to appear in 2000, there has been little change in both the growth rate of stripers and in their overall condition. Studies are showing that the number and size of stripers available has changed little and the total estimated population of baitfish remains steady at about 60-90 million. Contrary to the intentions of groups that have stocked large numbers of alewives and bluebacks into Lake Norman, there has been no significant effect on the striped bass fishery.
Coincidentally, parasites, known as gill maggots, have infested the striped bass population in Lake Norman. It is possible that these parasites were introduced to the lake through stockings of non-native fish species. Future studies will help assess the long-term effects of the introduction of alien fish species on striped bass in Lake Norman.
Catfish:
So far, catfish populations seem to be stable and unaffected by the influx of alien species. Since catfish generally inhabit the bottom areas of the lake and spawn in cavities, they could be least affected. Possible long-range effects are being monitored.
Summary:
The introduction of non-native alewives and blueback herring into Lake Norman is displacing the numbers of native shad. Unlike shad, which feed on zooplankton, alewives and bluebacks feed on the eggs and young of other fish species.
The introduction of white perch into Lake Norman, whether intentional or inadvertent, has caused the demise of white bass. Like alewives and blueback herring, white perch feed on the eggs and young of other fish species where their ranges overlap.
The reproduction of largemouth bass has declined in recent years. Reduced spawning success may have positive results in the short term by reducing competition for food among the bass population. However, if recruitment of young bass into the system continues to decline in the future, there will likely be a negative impact on the largemouth fishery.
Although studies show no significant current changes in the numbers and condition of crappies, bluegills, spotted bass, and striped bass, these species will continue to be monitored closely.
What Can Be Done?
The impacts of stocking alewives, blueback herring, and white perch, however well intended, clearly show the consequences of introducing non-native species into a new environment. Avoiding such negative impacts is the primary reason for new regulations prohibiting stocking of fish without a permit in public waters throughout North Carolina.
Although there are no practical ways to reverse the effects of non-native fish stockings in Lake Norman, some positive actions have taken place and there are plans to enhance the fishery in the future.
After analyzing data developed on various bodies of water across the state, the Wildlife Resources Commission instituted a new regulation, effective on July 1 of this year, banning the stocking of all fish species in public waters across North Carolina without a special permit. Fishermen bringing live bait from other bodies of water are not allowed to dump their remaining bait into the lake or river at the end of the day. Doing so may result in a fine. This new regulation will, hopefully, minimize the incidences of “bait bucket stocking” in all bodies of water across the state while providing authorities with enforceable rules to deter additional stockings in Lake Norman.
Anglers are encouraged to make sure any live baitfish they use are native species from Lake Norman. Live baitfish from other waters must not be released into the lake at the end of the day. Anyone who sees illegal stocking taking place is asked to report violations by calling 1-800-662-7137. Please be prepared to provide as much information as possible including vehicle or boat description, tag or vessel number, and location.
In cooperation with the North Carolina Wildlife Federation, Duke Power, and NC Wildlife Resources Commission, the Lake Norman Fisheries Committee is developing a plan to increase shoreline cover for various fish species. Young striped bass, largemouth bass, crappies, and spotted bass can benefit from appropriate increased cover to avoid predation. We will be asking individual homeowners and organizations to assist in the development of shoreline covers once the plan is finalized. Any individuals or organizations willing to help enhance fish habitat in Lake Norman are asked to please email ncwf_charlotte@mindspring.com or phone 704-332-5696.
Scientific Report
Available:
A summary of a recent scientific study developed by North Carolina State University on the Lake Norman and Badin Lake striped bass fisheries will be available soon on the NC Wildlife Resources Commission website at www.ncwildlife.org.