However, researchers studying zebra mussel reproduction have unveiled previously unknown facts about zebra mussel physiology which may accelerate the development of other control methods. Zebra mussels, accidentally introduced into North American waters in the mid 1980s, have spread rapidly to all of the Great Lakes and a growing number of U.S. and Canadian inland lakes and rivers. One reason for the rapid spread of zebra mussels is their enormous reproductive capacity.
Recent studies estimate that one female zebra mussel can release at least a million eggs per year.
Due to the mussels' prolific nature, a possible approach to their control may be to disrupt reproduction. Researchers are examining mechanisms that regulate spawning in this bivalve and are working on developing species specific, ecologically safe control methods which target the reproductive cycle of zebra mussels. Cues Regulate Spawning Bivalves spawn in response to both environmental cues and internal chemical cues. For example, in western Lake Erie, the zebra mussel spawn peaked in 1989 following a late summer increase in phytoplankton, ensuring adequate food for the developing larvae. However, when the late summer phytoplankton levels were much smaller than usual in 1990, the spawning peak never occurred.