The findings imply that dolphins cannot minimise the impact of human-made noise, even by adjusting their own vocal behaviour.
Along with international colleagues, the Bristol team equipped two trained and highly motivated bottlenose dolphins at the Dolphin Research Center in Florida, USA, with suction-cup attached tags, allowing them to record the dolphins’ vocalisations while the dolphins participated in a cooperative task. During the task, the dolphins had to work together to both press their own under-water button within one second of each other, while exposed to increasingly louder levels of noise.
The dolphins produced louder and longer whistles to compensate for the increasing noise levels but were still less successful as the noise got louder.
Paper: Pernille M. Sørensen, Abigail Haddock, Emily Guarino et al. (2023). Anthropogenic noise impairs cooperation in bottlenose dolphins. Current Biology.