Event Detail

Event Type: 
Mathematical Biology Seminar
Wednesday, November 13, 2019 - 16:00 to 16:50
STAG 160

Speaker Info

Department of Fisheries & Wildlife, Oregon State University

Age-structured populations exhibit a characteristic response to environmental variability. Variability (e.g., short-term anomalies in growth or survival) at time scales similar to the mean generation time tend to be amplified, while variability at other time scales tends to be dampened (except for very long time scales). This is termed ‘cohort resonance’ because it is associated with the passing of anomalously large or small cohorts through the population. The intensity of this effect depends on the breadth of the age distribution of reproductive adults: if reproduction is concentrated into just a few ages, cohort resonance is very strong. Because harvest tends to remove older individuals and narrow the age distribution, it can intensity cohort resonance. I show how cohort resonance can be understood and analyzed using frequency analysis and Fourier transformations, and the implications of it for the conservation and management of fish populations.