Effects of intense storm events on a marine top predator’s occurrence and foraging behavior

Background/Question/Methods

As storms become increasingly intense and frequent due to climate change, we must better understand how they alter environmental conditions and impact marine species. However, storms are ephemeral and provide logistical challenges that prevent visual surveys commonly used to understand marine mammal ecology. Thus, relatively little is known about top predators’ responses to such environmental disturbances. In this study, we utilized passive acoustic monitoring to characterize the response of bottlenose dolphins (Tursiops truncatus) to intense storms off Maryland, U.S.A. from 2015 through 2017.

Results/Conclusions

During and following four autumnal storms, dolphins were detected less frequently and for shorter periods of time than before the storm. However, dolphins spent a significantly higher percentage of their encounters feeding after the storm than before or during. This change in foraging may have resulted from altered distributions and behavior of their prey species, which are more prone to respond to environmental changes, such as varied sea surface temperatures caused by storms. As climate change alters, intensifies, and increases the frequency of storms, it is vital to determine how storms alter oceanography, prey movements, and the behavior of top predators.