The levels of anthropogenic noise in marine environments have been increasing the past decades due to expanding marine industries, such as shipping, fisheries, wind energy, seismic surveys, and oil exploitation. The increased noise may have severe negative impacts on marine mammals, affecting both individual fitness and population dynamics. Effects can range from missed foraging opportunities to hearing damage and possibly stranding. Such effects may not only be through behavioural alterations and interference with the animal’s biosonar, but also through direct and indirect physiological responses to noise disturbances. Because these elusive animals historically have been hard to access and study, we know relatively little about their physiology, let alone their physiological response to disturbance. My research revolves around the diving physiology of small toothed whales using new biologging tags that measure the diving behaviour (depth, acceleration), sounds, and cardiac activity (electrocardiogram) of freely swimming animals during deployments of up to 40 hours.
During my PhD I am investigating the normal function and regulation of the dive response in harbour porpoises (Phocoena phocoena), as well as potential cardiac responses to startling and anthropogenic sounds such as mid-frequency sonar. I work with the trained porpoises at the Fjord & Belt Center in Denmark, where we previously showed that harbour porpoises have cognitive control of their diving heart rate (Elmegaard et al 2016). Furthermore, for the coming two years, I will investigate heart rate regulation of wild harbour porpoises in relation to their behaviour and environment, including during noise exposures.
Contact information:
marinebioacoustics.wordpress.com 