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Underwater noise

Water is an ideal medium for the propagation of sound: acoustic waves travel four times faster than in air and sound attenuation is considerably less. 

Most marine mammals (whales, dolphins, porpoises and seals), many marine fish and even some shellfish use sound to communicate, to locate mates, to search for prey, to avoid predators and hazards, and for short- and long-range navigation. Humans are engaged in a number of activities that produce underwater sound which can affect marine organisms in various ways. Anthropogenic underwater sound can mask important signals such as echolocation clicks or communication calls; it can lead to a variety of behavioural reactions; it can result in hearing loss; and at very high received levels, sound can injure or even kill marine life. The distribution and level of sound generating activities is very difficult to quantify and long-term data on trends in ocean noise is patchy. There are considerable gaps in our understanding of the effects of noise on marine life - for example on behavioural reactions - which make it very difficult to assess effects conclusively.

We have a wide range of expertise on underwater noise. We conduct playback studies to investigate behavioural effects on fish, model ambient noise profiles based on field measurements and are developing risk assessment frameworks for noisy activities. Cefas also provides advice and undertakes research on underwater noise for the UK government (DECC, Defra) national organisations such as COWRIE (Collaborative Offshore Wind Research Into the Environment) and the ALSF (Aggregate Levy Sustainability Fund). Our international list of customers includes the International Association for Oil and Gas Producers and the Danish Government. Last but not least we provide leading input into international policies dealing with noise such as ICES and OSPAR.

Dolphin pod

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Last Modified: 01 May 2014