Assessing the potential for differential contributions of spawning stocks to Lake Erie yellow perch populations.

摘要

To determine how the heterogeneous environments in the western and central basins of Lake Erie influence reproduction and recruitment of yellow perch, I conducted a series of field and laboratory studies to measure the energetic and performance traits of various life stages. In Chapter 2, we examine the spawning behavior of yellow perch in the western basin by relating the presence and abundance of adult yellow perch during the spawning season to environmental variables. Here, we also estimated the timing of yellow perch spawning in this area by comparing the relative abundance of gravid and spent females through time and in relation to changing environmental conditions. In Chapter 3, we measured spatial variation in female reproductive traits among multiple spawning aggregations in the western and central basins of Lake Erie. We then demonstrate how spatial differences in demographic parameters influence population-level reproductive effort using a deterministic egg model to simulate total egg production under different mortality scenarios. In Chapter 4, we compared juvenile yellow perch traits at the end of their first summer across the western and central basins of Lake Erie. In Chapter 5, we measured elemental concentrations in the otoliths of larval yellow perch sampled from different regions of the western basin of Lake Erie and attempted to discriminate fish sampled from different regions using multi-element signatures. Finally, in Chapter 6, we reared juvenile yellow perch under different elemental concentrations crossed with three temperatures to determine the interactive influence of ambient elemental concentrations and temperature on otolith chemical composition.;From an ecological perspective, this research was an attempt to identify factors that may influence annual population fluctuations in yellow perch. From an applied, management perspective, we were attempted to identify recruitment mechanisms that can be manipulated to better manage yellow perch in Lake Erie. Fish recruitment is a process driven by the complex interactions of many abiotic and biotic factors and many of these factors, such as environmental conditions, are uncontrollable. The identification of recruitment mechanisms that can be affected via management initiatives would be invaluable to managers and greatly advance our ability to manage fish populations.