We are going to describe some simple life-cycle models that can be used to put current management and propose actions to expected fish responses into the context of their population dynamics, management goals (e.g. recovery criteria) and extinction probabilities.
2020 Video Lecture
Columbia/Snake River Salmon and Steelhead, Intro
This first lecture is an introduction to salmon and steelhead life-cycles and management complexities that highlight the need for some sort of accounting methods as to the impacts these various actions have during different life-stages relative to what we might be proposing. A life-cycle modeling approach is how we often attempt to quantify these responses.
Population growth models, a primer Part 1
This lecture describes some of the more basic population growth models. These models assume closed populations, no individual variation, no age or life stage structure, are deterministic, and do not contain time lags. Still they are the basis of some of the life-cycle models used to evauate fish populations.
Age-structured population models, a primer Part 2
Most organisms have maturation, fecundity, and survival rates that change as they age. Therefore models that include these differences add a bit more reality than the previous population models and provide different predictions of population growth rates and dynamics. Here we describe basic life table models as an accounting tool to describe vital parameters across different ages. We also describe matrix models as a means to project these vital rates across time and calculate population growth rates.
Multistage density dependent models, a primer part 3 (had to do this in 2 videos)
Because density dependent regulation is often found in fish populations even at somewhat low densities is necessary to combine DD with age-structure in population life-cycle models. A Beverton-Holt based model is now commonly used to model the effects of fish habitat condition on salmon and steelhead popluations in the Columbia River Basin. We provide examples we have worked on (video 3a) and how we populate these models (video 3b).
Kareiva, P., M. Marvier, and M. McClure. 2000. Recovery and management options for spring/summer chinook salmon in the Columbia River Basin. Science 290:977-979. DOI: 10.1126/science.290.5493.977
Weber, N., N. Bouwes, C. Justice, and S. White. 2018. Life - Cycle Model for upper Grande Ronde and Catherine Creek Spring Chinook - Evaluation of Habitat Restoration and Population Recovery Strategies. Prepared for the Bonneville Power Administration by Eco Logical Research and the Columbia Intertribal Fish Commission. DOI: 10.13140/RG.2.2.23968.43524