Fishing for Information: Quantitative Analytical Methods for Population and Community Assessments

Natural resource managers often use quantitative methods to characterize and manage ecosystems. A firm understanding of these methods, ranging from simple counts to complex models, is critical in conducting accurate population and community assessments. Students can gain an advantage in understanding these methods through early exposure and contextual examples. This fictional case study follows three American Fisheries Society club members who perform an ecological assessment of a landowner’s ponds. The club members use multiple sampling methods and analyses to answer the landowner’s questions. In this study, students are introduced to common assessment metrics, such as community patterns (richness, diversity, evenness, and similarity), abundance estimates (mark-recapture, depletion, swept-area, and line-transect), size structure (proportional stock density), and growth estimates (absolute, relative, and instantaneous growth rates; von Bertalanffy growth model). Students will also interpret results and identify physical or biological factors that may influence those results. After completing this case study, students will be able to describe the need for population and community assessments and apply these assessments to various scenarios.