The zebra mussel is a macrofouler. It quickly colonizes new areas and rapidly achieves high densities. Unlike native mussels that burrow in sand and gravel, zebra mussels spend their adult lives attached to hard substratum. Under natural conditions they are found on rocks, logs, aquatic plants, shells of native mussels, and exoskeletons of crayfish. They can also attach to, plastic, concrete, wood, fiberglass, iron surfaces (Figure 2), and surfaces covered with conventional paints.
In 1988 and 1989, zebra mussels were first found in water intake pipes in industrial and municipal water plants in Lakes St. Clair, Erie, and Ontario. The Monroe water plant in Monroe, MI, had to temporarily suspend service when its main intake line became clogged with zebra mussels. Many power plants along Lake Erie now spend more than $250,000 each year on control. Infestations have caused temporary power outages and difficulties in obtaining water for cooling and waste removal. Within their range, they could render inoperable miter gates on locks, fire prevention systems that use raw water, 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. When a thick layer of zebra mussels covers a metallic surface it can cause anoxia, and pH reduction, exacerbating corrosion rates. Estimates are that this species could cause 5 billion dollars in damage in the United States by the year 2000.