The distribution of 0+ perch,Perca fluviatilisL., in a lacustrine environment is described. Since the perch occupied many different habitats within the ecosystem throughout their first year of life a number of sampling techniques were required to sample the population. The early larvae and post larvae were planktonic and their distribution could be related to the effect of the winds. As soon as the young perch developed fins an inshore migration began. Virtually all the fish had completed this migration by the time they reached a total length of 19 mm but the majority of the population reached the shoreline before attaining this size. During June and August the 0+ perch formed large shoals around the shoreline especially in sheltered areas in water less than 3 m deep. At the end of August probably in response to falling lake temperatures the perch fry migrated into deeper water.