Resilience is the persistence of a population despite destabilizing forces. Portfolio theory states that the loss of diversity increases risk similarly in the ecological context as in the financial case (Figge, 2004). The key to an ecological application of portfolio theory is the diversity of ecosystem components that perform similar functions under differing environmental conditions, thereby reducing the variability in the overall ecosystem function. Complementary dynamics within a species-rich ecosystem and complementary life history strategies among sub-populations enhance resilience through variance dampening. Resilience conferred to a population via portfolio theory has yet to be investigated within a population, at the level of population age structure. The goal of this study is to build an IBM to evaluate the resilience of a long-lived rockfish to fishing pressure and environmental variability when the diversity of age-dependent reproductive strategies are diminished. There are two objectives for this study: 1) build an IBM that can represent two states of nature regarding reproductive biology of POP that can be utilized in a management strategy evaluation and 2) evaluate population response to anthropogenic and environmental forcing under two hypothesized states of nature.
Linsey Arnold, Department of Fisheries and Wildlife, Oregon State University
Fisheries and the Environment (FATE)