Sound is essential for communication and sensing in dolphins, so anything that disrupts it could be bad news. That is why conservation science company SEA, in collaboration with the US Navy, has been tracking how sonar similar to that used in military submarines and ships affects the behaviour of large groups of these mammals. These systems have been around for decades and use sound waves to detect underwater features and objects, but there are open questions “about why certain types of sonar would be particularly impactful” and why certain species are “more sensitive”, says Brandon Southall at SEA, the lead researcher on the project.
To understand the impacts on dolphins, his team monitored the response of pods off the coast of California as sonar devices were dipped into the sea at specific locations by military helicopter. They found that “these animals can detect and respond to these types of signals in different ways in terms of changing or calling behaviour, in terms of changing movement and speed and spacing”, says Southall. It is hoped that insights into how sonar affects their social dynamics can be used to mitigate harm in the future.
Topics:
