The Unrepentant Selectionist's Guide to Salmonid Management 2. A Selection Toolbox for Salmonid Management

Natural selection is the engine of adaptive evolutionary change and occurs when individuals with particular trait values have higher fitness than other individuals. While the mechanism of selection acts on individuals, selection’s effect is manifest as a change in the distribution of phenotypes within a population. There are myriad ways to visualize and quantify selection and its effects, including both parametric and non-parametric approaches as well as methods that are appropriate for the analysis of cross-sectional or longitudinal datasets.  In the first of our paired presentations, we emphasized why managers should care about natural selection operating in managed populations. Here we build on that discussion to provide some examples of selection quantification tools and approaches that might be proactively applied in salmonid management efforts. Of particular importance to managers of small populations, phenotypic shifts due to selection have the potential to influence population dynamics, and we will additionally highlight methods for teasing apart the importance of trait versus environmental variability on population dynamics and persistence.