Environment

Dolphins - Noise Pollution

Dolphins have to ‘shout’ to hear each other over ocean noise pollution, a new study reveals. Dolphins in noisy environments struggle to communicate and cooperate on tasks, researchers from the University of Bristol, UK, have found. This could have wide ranging implications for marine life.

Sound travels far further underwater than light, and up to three times faster in water than in air, making it an essential form of communication for dolphins and other marine mammals. They rely on vocalisation to find prey and mates, to navigate, and to work together. In recent decades, human-made underwater noise pollution has dramatically increased. Shipping, drilling for projects like offshore wind farms, fishing vessels, military sonar and tourism are all culprits.

The European Commission found that underwater background noise levels have doubled every decade in the last 60 years, mainly because of shipping. Noise pollution can also disrupt ‘echolocation’, the sensory ability of whales and dolphins to find food, socialise, and navigate underwater. In extreme cases, it can even cause physical harm, including temporary hearing loss