CLA Hosts Scientific Symposiums About Aquatic Life in Chautauqua Lake

July 17, 2009

The Chautauqua Lake Association recently sponsored two scientific symposiums led by Cornell University’s aquatic scientist, Robert Johnson, at the Chautauqua Suites in Mayville and at the Casino in Bemus Point.

“Chautauqua Lake’s Aquatic Plants and Associated Insect Herbivores” was the subject of the hands-on presentations allowing participants to peer at insects through microscopes and view various types of aquatic vegetation native to the lake in plastic bins.

Johnson talked about what types of plants were growing in the lake this year. “We have seen a lot of the native elodea and the introduced invasive curly-leafed pondweed in the spring and early summer of 2009,” he said. Elodea, a native is a rooted, perennial plant growing throughout the lake. This dark green aquatic plant is an important part of the lake’s ecosystem. It provides good habitat for many aquatic invertebrates and cover for young fish and amphibians. Waterfowl, especially ducks, as well as beaver and muskrat eat this plant. Curly-leafed pondweed, an introduced invasive, gets its name from the rippled or wavy nature of its submerged leaves and has limited food value for wildlife.

Non-native Eurasian watermilfoil, one of the most aggressive and problematic plants because of the dense colonies which it forms, is being held in check in Chautauqua Lake this year according to Johnson.

“Our team has been following insect populations, specifically moths, weevils and caddis flies that are selectively feeding on watermilfoil and limiting growth. This spring we recorded very large populations of the moth Acentria and caddis on the aquatic plants in several areas around the lake,” he said.

Johnson stressed the fact that lake residents can do more to provide healthy environments for these insects to flourish by not mowing their lawns all the way down to the lake shore and planting buffers of wetland emergents and woody shrubs along the shoreline. “The introduction of unmanaged buffer zones along the lakeshore would provide habitat to allow increased populations of beneficial aquatic plant herbivores, as well as the traditional use of buffers to limit nutrient runoff into the lake.”

Although caddis flies are slender in appearance, they are voracious eaters according to Johnson. “We have found large numbers of adult and larval caddis and moths this spring in the south basin at Burtis Bay, Greenhurst and Sunnyside and the north basin at Camp Merz and Maple Springs. All of these areas have low abundance of the non-native invasive Eurasian watermilfoil this season.”

He noted the recent planting of vegetation and woody plants along the shoreline by staff at Chautauqua Institution would help limit the overall spread of nuisance vegetation in the lake because of the natural habitat it will provide for hungry insects. “This is a good example of what can be done to help curb excessive plant growth in the lake,” he said.

The symposiums provided both lake residents and members of various lake organizations with helpful scientific information. Representatives from the Chautauqua Lake Management Commission and the Chautauqua Watershed Conservancy attended.

CLA President, Chris Yates, supports all of Johnson’s efforts and believes a scientific approach is the best one when it comes to preserving the lake’s health and beauty. “The entire staff and Board of Directors of the CLA whole-heartedly agree that by collecting long-term scientific data, we can use this information to make prudent lake management decisions in the future,” he said. “The CLA’s main objective is to keep the lake at its natural best.”

The symposiums concluded with a question and answer period. Subjects discussed included proliferation of the zebra mussel, herbicide spraying, weed harvesting and the dangers of using of detergents and other products containing phosphates.