You Are What You Eat: Advances in Marine Predator Diet Estimation via Fatty Acids
In marine ecosystems, estimating predator diets can be especially challenging since feeding cannot typically be directly observed. In this context, quantitative fatty acid signature analysis (QFASA) was devised as an indirect method of estimating predator diets and has successfully been applied to a variety of seabird species, marine mammals and fish. The approach estimates the proportion of each prey species in a predator’s diet by matching the predator and prey fatty acid signatures.
From a statistical methodology and analysis perspective, diet estimation by way of fatty acid data present several challenges, primarily because both the fatty acid signatures and diet estimates represent compositional data, but also due to a variety of practical considerations. In collaboration with biologists at various institutions across Canada, my research has focused on extensions to QFASA, inference procedures for predator diets, and the development of new probabilistic models for diet estimation through fatty signature analysis. In this talk, I will highlight some recent advances and ongoing work in this area.