Meeting Abstract
While many studies have examined the sensitivity of marine animals to underwater noise an essential component of any risk assessment is the likelihood that individuals of a given population will be exposed to that disturbance. An essential component of risk assessment is identification whether individuals will be exposed to a risk. This requires information on the proportion of the population exposed, for how long, and during what activity (i.e., feeding, migrating, and breeding). Using satellite telemetry data for humpback and blue whales feeding and migratory regions in Antarctica, California, and Bering Sea, we modelled the potential exposure of individuals to an acoustic disturbance. Foraging and transit regions along the tracks were identified and using a switching state space model the time spent foraging in each region calculated. A simulated seismic survey was randomly placed (100 iterations) within the habitat of each of species and the amount of time individual animals were exposed determined. A large disturbance (i.e. 100 km) only exposed 6% of the population of humpback whales in Antarctica and 19% blue whales off California. In contrast, humpback whales in the Bering Sea experienced high exposure with only a 5 km disturbance. This approach can be used to develop a framework for estimating the likelihood that a given animal population would be exposed to disturbance and to develop general risk assessment guidelines. Output from this exposure model can be used to evaluate the potential effect of disturbance on an animals energy budget in terms of energy expended but not acquired and how that would effect on offspring growth and survival.
