Zebra mussels: filter feeding foes
Our Stewardship team is dedicated to preventing the spread of aquatic invasive species in Adirondack waters. We accomplish this through a combination of boat inspections, free boat wash stations, and public education. The Adirondacks are home to more than 3,000 lakes and ponds, with roughly 25% of those waterbodies having at least one aquatic invasive species present. Although this percentage is lower than other regions of New York State, millions visit the Adirondacks each summer, with many of these visitors coming from regions with a higher concentration and diversity of aquatic invasive species. Invasive species are found throughout the Adirondacks, and with the combined efforts of AWI’s Stewardship program, partnerships with state and local agencies and organizations, and the assistance of community members, the further spread of aquatic invasive species such as the zebra mussel can be prevented.
What are zebra mussels?
Zebra mussels are a freshwater mollusk considered an aquatic invasive species in the United States. Zebra mussels (Dreissena polymorpha) originate from the Black and Caspian Sea region of eastern Europe and western Asia. Often distinguished by its unique coloration and zig-zag pattern, the zebra mussel is a small fingernail-sized mollusk. The mussel is easily dispersed and established in new water bodies due to its small size, life cycle, and its tendency to grow in large colonies. Although small, these invasive organisms can cause large disruptions to our aquatic ecosystems, the economy, and human health.
How do I identify zebra mussels?
Zebra mussels are often confused with the quagga mussel (Dreissena bugensis), another aquatic invasive species found throughout the Great Lakes region. Zebra mussels are triangular in shape, around two inches at maturity, with alternating dark and light stripes, similar to a zebra. The quagga mussel tends to be rounder in shape, and of slightly lighter coloration. While the zebra mussel has a stripe pattern, the quagga mussel tends to present a ring pattern. Along with these anatomical differences, the two species also have different preferred habitats. Quagga mussels can thrive in a larger variety of lake surfaces, including deeper water, colder water, and in more environmentally stressed waterbodies. Both of these species are filter feeders that cause disruptions to native mollusks and other organisms.
Are Zebra mussels harmful?
Zebra mussels cause challenges to our environment, economy, and to human health. These filter feeding bivalve mollusks filter large volumes of water in order to consume plankton. Phytoplankton and zooplankton form the bottom of the food web and are vital components of every lake ecosystem. The removal of plankton creates changes in water clarity, which - though sometimes favored by people - causes changes throughout the aquatic ecosystem. Zebra mussels also attach to equipment along shorelines such as boating and fishing equipment, docks, and pipes. Mussels attach by the hundreds and thousands to intake and drainage pipes and have caused millions of dollars of damage to drinking water infrastructure and to private and public properties. To add to their disruption, they create a difficult swimming environment with their sharp shells, and produce an unpleasant smell when found rotting on shore.
Where are zebra mussels found?
Zebra mussels are primarily found in freshwater up to depths of 50 feet, attached to surfaces such as rocks, sand, or equipment along a lake bottom. Zebra mussels are considered to be widespread in most of New York State. Initially discovered in the Great Lakes region in the 1980’s, these invasive organisms can now be found throughout Lake Ontario, Lake Erie, and in many of New York’s larger inland lakes such as Cayuga, Seneca, and Oneida Lake. In the Northern New York, Zebra mussels can be found in Lake Champlain, Lake George, Lake Bonaparte, Black Lake, and along the St. Lawrence Seaway. The mollusk is often found in large colonies of sometimes up to 750,000 per square meter near water intakes, pipelines, canals, and currents due to its accumulation in areas of constant supply of food and oxygen.
How do Zebra mussels spread?
Similar to other aquatic invasive species, zebra mussels are primarily spread through hitching a ride from one waterbody to another on boats and boating equipment. Zebra mussels can be transported through live wells, in and along boat motors, trailers, and on other equipment by using their byssal threads. The byssal threads are tough strands with a sticky substance at the end, which allows them to attach to surfaces. If transporting boating equipment to another waterbody, it is recommended to clean, drain, and dry that equipment before use. If visiting the Adirondacks, visit one of the several boat wash stations found throughout the region. Once in a waterbody, zebra mussels are difficult to remove.
If you discover zebra mussels in a waterbody, report your sighting to iMAP. This online tool provides a format for community members, researchers, and invasive species professionals to have access to updated maps and information regarding invasive species trends. By inspecting your boating, fishing, and recreational equipment before and after use, you lower the risk of zebra mussels and other aquatic invasive species from spreading into additional waterbodies.