This Impacts Section was edited for scientific content by:
Danielle M. Crosier and Daniel P. Molloy
Division of Research & Collections
New York State Museum
Field Research Laboratory
Cambridge, New York 12816
In August of 1988 (Hebert et al. 1989) the adult zebra mussel was first sighted in Lake St. Clair near Detroit, Michigan. The zebra mussel was believed to be released into the Great Lakes Region from the emptying of the ballast waters of an Eurasian vessel sometime in the mid-1980s (Nalepa and Schloesser 1993).
(Chronological Highlights of the Zebra Mussel Invasion)
The zebra mussel (Dreissena polymorpha) has become the most serious nonindigenous biofouling pest ever to be introduced into North American freshwater systems. It has the ability to tolerate a wide range of conditions and is extremely adaptable. It has the potential to significantly alter the ecosystem in any body of water it inhabits. To facilities that depend upon water intake, zebra mussel fouling can have a serious economic impact.
Europeans have witnessed the zebra mussel's ability to severely foul both industrial and domestic facilities as well as significantly alter freshwater ecosystems for the past century. These impacts became a reality for biologists, engineers, and ecologists in North America when severe fouling was observed just 3 years after introduction of zebra mussels was confirmed. Its impacts are widespread. Industry and utility plants have experienced clogged or blocked intakes, clogged or blocked distribution piping throughout the facilities, an increase in the corrosion of iron or steel piping and riveting, as well as the fouling of pumps, forbays, and holding tanks, trashracks, and condenser units. The following passage provides an overview of the types of problems encountered in raw water systems (U.S. Army Engineer Waterways Experiment Station 1995):
“Zebra mussels could render inoperable miter gates on locks, fire prevention systems..., reservoir release structures, navigation dams, pumping stations, water-intake structures, dredges, and commercial and recreational vessels. Materials and equipment, such as small-diameter pipes, seals, valves, gears, air vents, weep holes, screens, trash racks, chains, pulleys, and wire ropes are vulnerable.”
Water treatment facilities also have experienced fouling and loss of intake heads, obstruction of valves, corrosion of cast iron and steel piping, the putrid smell of decaying mussels, and buildup of methane gasses from the decaying mussel tissue. Boaters and recreational facilities experienced the fouling of boat hulls and engines, heavy fouling of navigational buoys, which rendered many of them useless, the accumulation of windrows of mussel shells along beaches and shorelines and the encrusting of docks and gear with colonizing mussels.
Ecologists and biologists saw the potential for the alteration and destruction of existing habitats, elimination or decline of various indigenous species, and changes in water quality. They came to the realization that the zebra mussel was here to stay and was truly an alien species to be reckoned with.
The impacts on a facility or water body relate directly to the biological characteristics of this mussel. Major problems for man-made systems result from mussel attachment to a structure with byssal threads, the mussel’s high fecundity under suitable environmental conditions, its ability to translocate to more suitable areas, the mussel’s high tolerance for a wide range of conditions, and its microscopic, free-swimming veliger stage. See the Life History and Biology section for further details.