Short-term disturbance and the health of individuals and populations: approaches to quantify the potential biological significance of anthropogenic disturbance on cetaceans
Marine Mammal Center Seminar
Thursday, December 22, 2011
Redfield Auditorium - 12:00 Noon
Dr. Patrick Miller, PhD
Sea Mammal Research Unit, Scottish Oceans Institute, University of St Andrews, Scotland
While much of the focus of anthropogenic effects on cetaceans is on lethal effects to animals, concern has grown over recent years that cumulative non-lethal effects on the behaviour of individual animals might have consequences at the population level. My research has been focusing on this problem at two different time scales. The first approach is to use behavioural response studies at sea to attempt to quantify over what geographic scales the behaviour of free-ranging cetaceans is potentially altered by an anthropogenic source of disturbance, military sonar. In the 3S research collaboration we have conducted experiments with several species of whales in Norway, using a dose-escalation procedure designed to enable estimation of a dose-response function for defined responses. The second approach is to develop new methods to quantify the body condition of cetaceans at sea using high-resolution acceleration tags to measure body density, which varies depending on fat content. We have calibrated 3 data analysis techniques for estimating body density with trans-located elephant seals, and are currently using this approach to quantify the body density of toothed and baleen whales. Understanding how body condition is both affected by short-term disturbance and influences vital rates is a promising research avenue to link short-term disturbance to long-term consequences for individuals and populations.