In summer 2007, Otsego Lake was invaded by the zebra mussel – whose ill effects include ecological destabilization, damage to municipal, residential, and commercial intake pipes, production of sharp shells causing injury to recreational users of the lake, and emission of unpleasant odors. Once established, elimination of this mollusk is impossible, making control the best option.

The water chestnut has a stem which extends to the surface of the water and ends in a rosette of floating, saw-toothed leaves. The plant bears a spiky fruit, which can pierce tennis shoes and thick-soled boots. In addition, water chestnuts can clog pipes, canals and waterways and adversely affect the environment by removing oxygen from the water and out competing native vegetation. OCCA has spearheaded a manual eradication effort of the water chestnut on Goodyear Lake.

Best Management Practices

The best way to deal with water chestnut is by hand pulling all visible plants, making sure to include the roots as well. This is best done before June when the plants begin flowering and producing nutlets. For large infestations, mechanical harvest is best. Nutlets can persist in the substrate for up to 5 years and can be transported by waterfowl and geese, so continued monitoring and periodic removals are necessary.

A free-floating plant of still and slow moving waters, European frog-bit can quickly form dense mats that block sunlight and alter aquatic ecosystems. European frog-bit can be recognized by its round or heart-shaped, leathery green leaves, which are just 1-2″ across. Rosettes of leaves arise from a node on an underwater runner called a stolon. Stolons can grow to several feet long and have multiple rosettes arising from them. In mid-summer, the plant produces small flowers with three white petals surrounding a yellow center. In late summer, the plant produces vegetative buds called turions that fall to the bottom and produce new plants the following year.

Best Management Practices

For more heavily infested water bodies it is suggested to harvest near launches to help prevent its spread. Herbicidal options are available, but the treatment of severe infestations is usually ineffective and expensive.

Yellow floating heart can be identified by its round, heart-shaped leaves that float like “lily pads”, and its 5-petaled, yellow flowers. The flowers, which are visible from June to September, are fringed, making them distinct from the commonly confused Spatterdock, which forms a cup-shaped flower. Plantlets form at nodes interspaced along long, branching stolons (~6’ long). The leaves are typically light green and have wavy margins. The underside of the leaves can sometimes be light purple to reddish. Yellow floating heart produces tuberous rhizomes from the floating plantlets, but the main stolon is rooted in the substrate. The flower produces a capsule-like fruit that contains seeds with hairs that allow it to attach to waterfowl and other aquatic animals. Infestations can also spread from plantlets that wash downstream.

Best Management Practices

Mechanical removal is the most effective method for tackling this species, but glyphosate is a likely candidate for impactful chemical removals. If an herbicide were to be used, an application must be carried out with great caution so as to avoid native species, and ensure the chemical being used is aquatic safe.