Assessing Walleye Movement among Reaches of a Large, Fragmented River

AbstractMovement of Walleyes Sander vitreus among reaches in a large, fragmented river was assessed by employing a combination of tagging, telemetry, and genetic analyses. Our objective was to determine whether the existing dams in the Ottawa River, Canada, were impeding Walleye movement among river reaches. Movement was predicted to be greater among contiguous, unimpounded reaches in comparison with impounded reaches. In total, 1,586 Walleyes were tagged in five river reaches, and 35 Walleyes were tracked by radiotelemetry in three river reaches. Genetic analyses (linkage disequilibrium, genetic divergence and diversity, effective population size, genetic structuring, bottlenecks, and migration rates) were conducted on 221 Walleyes from seven river reaches by genotyping at six microsatellite loci. Based on both tag returns (return rate = 12.1%) and telemetry data, there was limited movement among river reaches whether impounded or unimpounded, and movement was predominately upstream. Genetic analyses ide...