Population Characteristics of the Invading White Perch ( Morone Americana) in Western Lake Erie

The white perch ( Morone americana) is an East Coast estuarine species that invaded Lake Erie in the 1950s, but did not increase in abundance until the mid 1970s. We studied its distribution and population dynamics in western Lake Erie during this period of rapid increase in population size. White perch spawned in riffle areas of tributary streams of western Lake Erie during late April, and then moved downstream into the lake. They were abundant in nearshore and reef habitats throughout most of the year, although a few were collected in deep offshore areas. Increasingly strong year classes were produced each year in 1980–1984. The age structure of the population reflected a surge in recruitment in the 1980s; fish of age–1 and age–2 were abundant, but older fish were still rare. White perch in western Lake Erie grew faster and matured earlier than those in most other populations, but growth rates appeared to be declining as the population expanded. White perch can be expected eventually to colonize suitable habitats throughout the Great Lakes.