Sound is essential to marine mammals for communication, orientation, navigation, prey detection and alertness – but they need to be able to hear! In recent decades, anthropogenic (man-made) noise has increased in the oceans, especially in the Northern areas due to increased shipping and oil and gas exploration. The opening of, until now, remote areas of the Arctic, means noise in areas that were previously protected by their inaccessibility.
Ocean noise is both pollution and disturbance. Besides possibly impairing and/or masking biologically significant information channels, noise may induce behavioural changes in marine mammals, such as alterations in surfacing, diving and resting patterns and the abandonment of crucial habitats. The chronic effects of increased noise levels and loud point sources (ships, explosives, constructions etc.) may potentially have effects at the population level.
There is insufficient information to understand the full extent of the problem. But marine noise is today recognised as a serious threat to marine mammals, notably cetaceans, with a pressing call for taking a precautionary approach in regulation.
Our use of the ocean will only continue to increase. It is not possible to remove all anthropogenic noise from the ocean, but it is possible to reduce some noise levels, and activities can be organised so they don’t happen in places and at times that are particularly sensitive for marine mammals.
You can read more on underwater noise here.
Listen to marine mammal sounds (© NEFSC-NOAA) and listen here to other kinds of marine sounds, from whales, to seals, fish, shrimps and vessels.