The yellow perch has a nearly circumpolar distribution and is of major commerical and recreational value in Canada. Adults of this species live and travel in schools that segregate roughly by size. Because this species is active throughout the year, fishermen can just as easily catch this species in winter (through the ice) as in summer. Because perch are so widespread and abundant, they play an important role in aquatic food webs. Perch undergo diet shifts with size, typically shifting from plankton to benthic invertebrates to fish as they grow. In lakes with small populations of perch predator species like walleye and pike, perch can reach extremely high densities; so high that they deplete their own food resources and become stunted.