ABSTRACT
Although yellow perch Perca fl avescens Mitchill are widely distributed in inland waters across Canada, east of the Rocky Mountains from the boreal forest southward (Scott and Crossman 1973), their ability to colonize northerly and high elevation river systems appears to be limited (McPhail and Lindsey 1970). Like all Canadian fi sh species their present natural range represents their ability to recolonize a completely glaciated landscape over the last 10-12 millennia by dispersal through postglacial drainage networks (McPhail and Lindsey 1970; Mandrak 1995). The limited northern range is consistent with their preference for warm, weedy littoral habitats of lakes and ponds (Nelson and Paetz 1992; Boisclair and Rasmussen 1996). Although the species has limited capacity to deal with current, yellow perch are sometimes found in rivers, albeit slow moving sections and fl oodplain habitats. Since river networks are the key to dispersal on the landscape, the limited tolerance of yellow perch for fl owing water might be expected to have restricted their range in steep areas such as the eastern slopes of the Rocky Mountains. In this chapter we examine both large and small-scale distribution patterns of yellow perch in Alberta and British Columbia, both native and introduced, by reviewing published and unpublished literature and government databases. We examine these patterns for insights into tolerances for climate, salinity and other habitat factors, and for dispersal and invasive abilities that may impact their future spread and their impacts on other species and fi sheries resources.
