Pacific Salmon Environmental and Life History Models: Advancing Science for Sustainable Salmon in the Future
Introduction: the Past, Present, and Future of Pacific Salmon Environmental and Life History Models
E. Eric Knudsen and J. Hal Michael, Jr.
Abstract.—Pacific salmon harvest, habitat, and hatchery managers are continually striving to find the most effective tools for estimating each population’s productive capacity, its response to environmental variables, and interactions among populations. This is necessary to determine appropriate management actions, whether the focus is on rebuilding depleted populations or on maintaining populations that are self-sustaining and robust. Many salmon populations exhibit reduced abundance compared to the past. Habitat degradation, hatchery introgression and competition, overfishing, and environmental variability have all been cited as reasons for these losses. One factor in past management problems has been the misapplication, misinterpretation, and technological limitations of traditional salmon population models. In this introduction to the book, we first briefly review the reasons why past modeling has often been ineffective and what managers need from models for them to be useful in practical applications. We then discuss a number of developing, alternative modeling approaches that account for weak data, parameter uncertainty, decision uncertainty, habitat capacity, and environmental and climate variability. Last, we review the practical needs for advancing salmon modeling science, based on the numerous recommendations from the chapters of this book. We emphasize the need for integrating modeling approaches so that harvest, habitat, and hatchery managers will be better able to synthesize and coordinate their salmon management decisions.