Invasive Species

Chautauqua Lake has a delicate ecosystem of plants, animals, microorganisms, and essential water chemistry balances. Introducing non-native or colonizing species can easily disrupt the ecosystem and should be avoided.

The National Invasive Species Council (NISC) defines an invasive water species as “an alien species whose introduction does or is likely to cause economic or environmental harm or harm to human health.” The term ‘invasion’ simply denotes the uncontrolled or unintended spread of an organism outside its native range.” 

NON-NATIVE PLANT SPECIES

Eurasian Watermilfoil and Curly-leaf Pondweed 

Chautauqua Lake hosts two non-native plant species: Eurasian Watermilfoil and Curly-leaf Pondweed. These plants were classified as invasive when they first appeared. However, they have been present for decades and are now considered long-established.

Curly-leaf Pondweed has become a significant component of Chautauqua Lake fishery habitat, serving as cover that slows the growth of Eurasian Watermilfoil. This long-established plant allows competing, slower-growing native plants to flourish. Curly-leaf pondweed naturally dies off during late June and early July.

Eurasian Watermilfoil remains active throughout the season and plays a vital role in the fishery. While it used to reach the surface in dense quantities, nuisance conditions have become rare due to the limiting effects of natural herbivores like moths, weevils, and caddisflies.

The Western New York Program for Regional Invasive Species Management (WNY PRISM) has classified them as Tier 4 Invasives. This ranking indicates that they have the lowest priority for invasive species management and that eradication is not feasible.

COMMONLY MISIDENTIFIED PLANTS

The two plants listed below are frequently mistaken for invasive species in Chautauqua Lake, but they are beneficial to the ecosystem.

Coontail is often mistaken for Eurasian Watermilfoil. It provides an essential function in fishery and with nutrient intake. It may grow to nuisance levels, but it can be best controlled through harvesting while maintaining some subsurface presence. 

Elodea is frequently confused with Hydrilla. While they share similar appearances, their leaf configurations differ. Elodea also benefits the fishery and is best managed through careful harvesting.

INVASIVE SPECIES

Zebra Mussels

Zebra mussels are another invasive species that have established themselves in Chautauqua Lake. They have been present for several years and have experienced fluctuations in quantity and size, the reasons for which are not yet fully understood. While zebra mussels are not found uniformly across the lake’s bottom, their local distribution is unpredictable. Therefore, recreational users are encouraged to wear protective footwear when interacting with the lake’s bottom.

Although Zebra Mussels resemble Quagga Mussels, they are a distinct species. It is important to note that no quagga mussels have been found in Chautauqua Lake to date.

PLANT SPECIES OF CONCERN

Two aquatic plant species of concern, Water Chestnut and Hydrilla, have been found in nearby water bodies and require vigilance to ensure they do not arrive in Chautauqua Lake.

HOW CAN YOU HELP?

If you encounter what you believe to be an invasive species, please take close-up pictures of the plant and send them along with a detailed description of the location where the plant was found, as well as the date and time of your discovery to the Chautauqua Lake Association at info@chautauqualakeassociation.org. CLA staff will follow up on your report.

The CLA partners with WNY PRISM to address invasive species issues and contributes to a comprehensive statewide database and action network. 

USEFUL RESOURCES 

• Western New York Partnership for Regional Invasive Species Management (WNYPRISM)
• Invasive Species Data and Mapping Resources
• Stop Aquatic Hitchhikers