Print PageThere are approximately 400 individuals remaining in the population of Northwest Atlantic right whales. These animals are subject to a variety of natural and anthropogenic stressors, the latter of which include ship strikes, entanglements with fishing gear, and exposure to chronic and acute sources of noise. All of these are presumed to impact the health and survival of this population, yet the effect of these stressors has proven difficult to quantify. This is in part due to the confounding effects of differential habitat use, differential sightability, and differential survey effort across the major habitat regions for right whales.
Results/Conclusions
Here we address this issue by building a Hierarchical Bayesian model for survival of individual right whales as a function of age, location, and health. We include a data model for sightings of individual right whales that follows a Poisson process, and process models for both movement between regions and survival through time. Outputs from the model include age and location specific estimates of survival for individual right whales. Consistent with the PCAD framework, we use these outputs to infer the differential risk associated with the major habitat zones on individual survival. We use these estimates of risk in conjunction with possible management scenarios to make suggestions that increase age and zone specific survival among individuals and the population as a whole.
