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Chautauqua Lake is a small, naturally formed lake in the Southwestern corner of New York State. The lake has long been plagued with problems of aquatic vegetation overgrowth. In fact, there is evidence of dredging these macrophytes that dates back to a project begun in 1887! While it is not known what types of plants were problems at that time, there are now two plants that have created a significant problem. Both species are exotic to Chautauqua Lake and have created threats to both other flora species, as well as native fauna. To fully understand the problem of aquatic plant overgrowth in this area, we must first examine the climate around Chautauqua Lake.

First, Chautauqua is a partially eutrophic lake. The North Basin of the lake is mesotrophic; in the South Basin, where the biggest problems with overgrowth exist, the lake is naturally shallow. Heavy siltation occurred when glaciers moved through the area tens of thousands of years ago. And to some degree, Chautauqua Lake is naturally abundant in its supply of nutrients, as is characteristic of a eutrophic body of water. However, eutrophication can also result from human intrusion and/or mismanagement of the watershed.

It is first important to understand the importance of agriculture in Chautauqua County. According to 1992 Chautauqua County Census of Agriculture, the market value of agricultural products sold was over $88 million; obviously, it dominates the county’s economy. But while it is a significant contributor to the economy, it also responsible for phosphate dumping from fertilizers, pesticide runoff, and nitrogen loading in the lake, all of which fuel the growth of aquatic plants.

Tourism is also a large part of the county’s economy – in the summer season, which runs from Memorial Day to Labor Day, recreational water vehicles (boats, jetski’s etc.) dominate the lakescape. This poses an interesting contradiction. On one hand, since tourism is a big business in an otherwise rather poor county, there is an inclination to keep weed levels under control so they do not damage motors. On the other hand, there is very obviously a negative environmental impact that results from heavy use of such recreational vehicles.

Additionally, although the character of the county as a whole is very rural, only about 13% of Chautauqua Lake’s shoreline remains undeveloped. The unsewered portions of the watershed, as well as the desire for sprawling expanses of gulf course-like weed free lawn also contribute to eutrophication.

But despite the negative impacts of these two very significant industries and the rural character that is so intrinsically a part of the county, there is a climate that fosters environmental stewardship. Groups such as the Chautauqua Watershed Conservancy and the Chautauqua Lake Association are examples of not for profit organizations that seek to protect the watershed. Another group is the Chautauqua Lake Local Waterfront Revitalization Project, which is a program that has set clearly defined goals for the lake, working in the context of a coalition of towns and villages that are in the lake’s watershed. Interestingly, in the surveys the LWRP has conducted regarding the areas of greatest environmental concern, submerged aquatic vegetation ranked #1 in all of the nine municipalities that are part of the coalition. The nine towns and villages included in the LWRP are Chautauqua, Mayville, Ellery, Bemus Point, North Harmony, Ellicott, Busti, Lakewood, and Celeron.

So, what methods are there to deal with such a popular topic? There are several, ranging in their effectiveness, price, level of environmental impact, and involvement of government.

A method that was widely used in the past is dredging. Dredging is the process of dragging the lake bottom to remove nutrient rich sediment as well as rooted, submerged aquatic vegetation. Dredging, while very effective, is also very expensive. There is also the question of what to do with the “spoils”. Historical documents from the late 19th Century have led planners to believe that spoils were often dumped in what were then deeper parts of the lake. An example of one such location is Burtis Bay, in the lake’s south basin, which now is one of the “most notorious shallow and week choked area of the lake” (Erlandson 2000). There is even speculation that repeated dumping may have led to creation of a new shoreline or to the formation of Grass Island.

A method similar to dredging is harvesting. Large cutters and barges are deployed into the lake. The cutters actually sever the stems of the plants at an underwater depth of about 5 feet. The cuttings are then loaded onto the barges for return to shore, where they are eventually disposed of. Harvesting is only partially effective. Often, fragments of vegetation are left behind after the cutting process and will immediately begin to grow again. For this reason, harvesting must be repeated during the course of the growing season. The cost of such a project is relatively expensive. Two harvesting operations in each basin generally run about $100,000 per summer. There have been suggestions to turn the harvested materials into nutrient rich (and saleable) compost to offset the costs of this operation, but to date, there are no plans in place to do so.

In addition to the concerns over cost and the limited effectiveness of harvesting, there are also questions of the effects of harvesting on the lake’s fauna. Recently, there have been notable declines in fish populations such as crappie, sunfish and bluegill. Cutting may prevent the stable recovery of these species for a couple of reasons. The most obvious reason is that fish, especially juveniles, often get caught in the cutters. Moreover, harvesting removes native vegetation, which does not form the same mats of impenetrable vegetation that non-native species do. Many fish rely on native vegetation for food (whether they eat the plant itself or microorganisms living on the plant) and also for protection from predators. Harvesting, then, destroys faunal habitats and food sources, leading to concern over ecosystem balance.

In the past, the use of herbicides was a popular means for controlling vegetation. There are several herbicides that are considered safe – Aquathol-K and Sonar have received the most attention from Chautauqua County. When applied correctly, specifically at the correct time during the growing season, herbicides are traditionally an effective means of controlling SAV, with a much more moderate price tag of $50,000 per summer. However, concerns over public health are always an issue. There is inherent suspicion on the part of the public when it comes to the application of chemicals to water. When water is treated, there needs to be sufficient public notice, since according to the Material Safety Data Sheet for Aquathol-K it may be dangerous to consume fish from treated water. Also, swimming and other water activities should be avoided for the recommended 3-day waiting period after application. This is also an obvious liability issue for the planning department.

There is often a lag time between the application of the chemical and when it takes effect and actually begins to affect the plants, which, with a short growing season, sometimes discourages the use of herbicides.

Another potential harm caused by Aquathol-K is the reduction in the amount of dissolved oxygen the in the water. As plants die and decompose, there is less oxygen in the water, which in turn, may cause fish to suffocate.

Legislation and infrastructure are two methods that directly involve government. Legislation could include regulations such as mandatory septic pumping every two to three years or planning projects dealing with greenbelt planning along stream corridors. An example of improved infrastructure would be to extend sewer coverage to every area of the watershed. There is currently no cost estimate associated with that idea, as it is not even under consideration by the county planning department. In fact, there has been no ambition on the part of the county planning office to undertake any such regulation.

The idea of education programs that will further environmental stewardship are important. Unfortunately, such programs are difficult to fund and staff. These programs, however, are often quintessential in achieving planning goals. In looking at the SAV issue, public education campaigns are twofold: first, to educate citizens on the ways in which they impact the watershed through daily practice and secondly, to educate them on other environmental methods in place surrounding the issue so as to foster an understanding and support of the program.

The most prevalent examples of public education in Chautauqua County are lakescaping (which promotes the use of native vegetation) and lawn maintenance workshops, both of which help the public develop environmentally friendly ways to garden and maintain healthy lawns, while at the same time preventing erosion, promoting natural filtration to reduce nutrient loading, and in general promoting good environmental health around the lake’s watershed. Biological controls are slowly entering the consciousness of those involved in decision-making. Often, the nuisance exotic plant species has one or more natural predators. The introduction of such a predator, or the augmentation of the native predator population, can result in a marked decline in the nuisance species. There is some question regarding the effectiveness of such controls, as well as possible impacts on the lake ecosystem as a whole. Of these planning methods, several have been tried by Chautauqua County over the course of the past decade. Harvesting is the most popular method, but herbicides see continued use in some of the municipalities. Biological controls were administered just this past summer, so the jury is still out on their effectiveness, but the approach seems to hold some promise.

Cornell University and the Chautauqua County Cornell Cooperative Extension have suggested both aquatic moths and aquatic weevils as possible biological control agents for Eurasian milfoilweed and curly leaf pondweed. Both aquatic moths and weevils have been proven to be detrimental to the problem exotic plant species. Moths and weevils are naturally present in the lake’s ecosystem, and there is thought to be some nexus between their location in the north basin and the generally lower rate of overgrowth in that environment. However, since the moths are only present in the North Basin, which is mesotrophic, it is not known if the decreased amount of vegetation is due to the mesotrophic composition of the lake or the presence of the moths. Bob Johnson, Manager of the Cornell University Research Ponds, suspects that it could be both. The aquatic weevils that are present in the lake as a result of the study did “cause extensive damage to the water milfoil” (Johnson 2002). This study is continuing as we speak, with augmentation happening this month. Once hatched, the moths are expected to produce further declines in exotic species growth during next summers growing season. The success of this type of control depends, however, on the continued maintenance of moth and weevil populations that are capable of controlling vegetation overgrowth over the long term.

The use of herbivores could very well be the future of SAV management. The method represents an environmentally conscientious technique, and is greatly aided by the fact that the control agent is native to the ecosystem, and is not merely the addition of yet another exotic species which may in time present its own set of challenges. Additionally, the method is viable over the long term and is economically feasible as well. So far, the county has committed roughly $50,000 to the study, much of which was research costs and travel expenses for the research team. Insect production costs were only about $10,000 of the $50,000. Add continued monitoring costs to that figure and it is still a far less costly method than applying chemicals or harvesting.

I believe that, although the problem of macrophyte overgrowth is not solved, (it is unlikely that is will ever be solved) Chautauqua County is doing what it can to manage the problem. There is a balanced interest on the part of the planning office between environmental considerations, economic interests, and the cultural climate of the area. In choosing harvesting as a short-term means of control while developing a healthier plan, one that will stabilize the environment more effectively, Chautauqua County is proving that they are responsive to both the environment and to the concerns of its citizens. As Chautauqua County looks to the future with biological controls in mind for the management of aquatic vegetation, the biggest challenge it now faces is determining if humans can successfully alter their precious ecosystem known as Chautauqua Lake in an attempt to meet their own needs.

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