Zebra mussels are found in freshwater lakes, ponds, embayments, and rivers. If temperature and water quality are appropriate, they can tolerate velocities up to 2.0 m/s. They typically are found where water temperatures range from 0 to 25 º C. They have been collected in shallow waters (less than 1 m deep), but maximum abundance usually occurs at depths between 2 and 14 m. Zebra mussels are clean water inhabitants and are usually found where dissolved oxygen is greater than 90-percent saturation. They are stressed in water with less than 40- to 50-percent saturation and 100-percent mortality occurs in the absence of dissolved oxygen. Zebra mussels, like all bivalves, require calcium to construct their shell. They have not been found in water with less than 10 mg/ l dissolved calcium.