Researchers found that despite increasing the volume and duration of their underwater whistles, dolphins’ ability to successfully communicate dropped by almost half at the highest audial distraction levels.
Dolphins are forced to “shout” and adopt other strategies to compensate for man-made noise caused by drilling, hipping and military activities, a new study has found.
Dolphins tasked with pressing a button within one second of a partner across a small lagoon “increased the level of their whistles in noise, nearly doubled whistle duration, and oriented more toward their partner, indicating that both dolphins were actively attempting to compensate for noise to continue communicating with each other,” researchers reported in a study published in Current Biology on Thursday.
But while the sea mammals have developed multiple methods of dealing with loud environments, they are apparently far from perfect.
“We found that the dolphin [pair’s] success rate in the cooperative task decreased with increasing levels of anthropogenic noise, irrespective of their attempts to compensate by producing louder and longer duration whistles and by changing their physical behavior to allow for better monitoring of their partner,” the researchers wrote.
“Cooperative task success decreased in the presence of noise, dropping from 85% during ambient noise control trials to 62.5% during the highest noise exposure.”
Noise pollution has emerged as a major issue for marine life, especially animals like dolphins that rely on echolocation to locate and track food sources. Scientists have linked the surge in oceanic background noise with an uptick in strandings, changes in behavior, and decompression sickness among cetaceans.
“If groups of animals in the wild are, for example, less efficient at foraging cooperatively, then this will negatively impact individual health, which ultimately impacts population health,” said Stephanie King, one of the study’s co-authors and associate professor at University of Bristol, said.
Their co-author, Pernille Sørensen, reportedly explained that the “same reasons that make sound so advantageous for animals to use also make them susceptible to disturbance from noise in the environment.”
The researchers claim the study is the first to “show how increasing levels of anthropogenic noise negatively impact coordination between conspecifics performing a cooperative task” in any non-human species.
Image credit: Pixabay
