Angling Nesting Bass Causes Fisheries-Induced Evolution

Long-term studies in Ontario, Canada of several populations of smallmouth and largemouth bass clearly demonstrate that lake-wide recruitment (i.e., annual year-class strength) is directly related to the reproductive success of the population.  In addition, it has been well documented that angling nesting males (both catch-and-harvest and catch-and-release) has negative impacts on the reproductive success for the captured individual.  Unfortunately, the male bass that are the most capable of having the greatest relative contribution to the year class are also those individuals that are the most vulnerable to angling.  As a result, angling for nesting bass results in selection against those males that are the most valuable for population level sustainability.  Controlled, long-term selective breeding experiments over 20+ years have documented the heritability of vulnerability of bass to angling.  In addition, field experiments assessing the long-term impacts of angling pressure during the nesting season demonstrate the level of behavioral change possible during this era of widespread angling-induced selection.  The long-term impacts of angling bass during the reproductive season is presented in the form of a conceptual model, which then serves as the basis for recommendations on what management changes are needed to assure long-term sustainability of wild populations.