Thursday, February 16th, 2012
9:30am - 10:30am, in Campus Center 2-2540

Peter Dillingham

George Perkins Marsh Institute

Potential biological removal: extending models to seabirds

Abstract: Incidental (bycatch) mortality by fisheries is one of the most serious conservation concerns for non-target populations of marine megafauna such as marine mammals, seabirds, sea turtles, sharks, and other large marine species worldwide. For many of these populations, data limitations and lack of appropriate quantitative tools hinder decision-making. A simple management tool used to set marine mammal bycatch limits in the US is the potential biological removal (PBR) method. The PBR method only requires an estimate of the maximum growth rate and a conservative estimate of the population size, along with a management-set recovery factor, to estimate the additional mortality that a population can sustain. However, even this limited data is unavailable for seabirds. Model-based approaches to estimating the maximum growth rate and the population size allow the PBR method to be applied to seabirds using only estimates of adult survival, age at first breeding, and the number of breeding pairs, extending the potential usefulness of the PBR approach beyond marine mammals.