A Fine-scale Analysis of Spatial and Temporal Population Genetic Patterns in the Yellow Perch (Perca flavescens)
The genetic structure of a species encompasses the distribution of genetic diversity and composition among its component populations, providing important insight for conservation and management. This knowledge can be used to evaluate life history, gene flow, recruitment dynamics, and responses to exploitation and habitat changes. Discerning the changes or consistencies in population genetic patterns over time can provide important insights into the mechanisms that regulate genetic resiliency. Ultimately, analyses of spatial and temporal population genetic patterns may be used to conserve genetic diversity, unique variability, and adaptive potential. The yellow perch Perca flavescens (Percidae: Teleostei) provides an opportunity to investigate these patterns, as its population groups have experienced variable annual recruitment, high exploitation as a popular fishery in the Laurentian Great Lakes, and have not been evaluated previously for temporal consistency in genetic patterns. The objective of this thesis is to analyze the spatial and temporal genetic diversity and divergence of yellow perch spawning groups in order to better understand its life history responses and advance knowledge aiding its management. Population genetic patterns of yellow perch spawning groups are assessed across the Huron-Erie Corridor (HEC) and from locations in Lakes St. Clair, Erie, and Ontario using 15 nuclear DNA microsatellite loci. Results of this thesis research indicate that yellow perch spawning groups have appreciable genetic diversity and are distinguished from one another by considerable genetic differences. For example, the group spawning at the Belle Isle restoration site in the Detroit River has relatively high genetic diversity, with an appreciable number of alleles and private alleles. Yellow perch spawning at sites in Lakes St. Clair, Erie, and Ontario also show substantial genetic diversity whose levels are consistent over time. However, the genetic composition of yellow perch spawning at some given locations varied among different sampling years. Some age cohorts born in specific years who spawned together at Dunkirk NY (1980-2008) and Monroe MI (1997-2004), genetically varied across age groups. This pattern did not correspond to a pattern of isolation by time (i.e., there was not a consistent trend). The effective population size of yellow perch spawning at the Dunkirk, NY location is relatively modest and appears to have remained relatively consistent in size over the past 30 years. These spatial and temporal patterns likely are linked to life-history characters, such as kin-aggregation, natal site fidelity, and/or a sweepstakes model of reproduction. Genetic monitoring and development of long-time data sets like those assembled here are recommended to provide an important management assessment tool for monitoring and conserving fishery populations.
Biology, Conservation, Ecology, Genetics, Lake Erie, Yellow Perch, Microsatellites, Population Genetics
Networked Digital Library of Theses and Dissertations