Noise

For most marine mammals, many marine fish, and perhaps some shellfish sound is important for communication, locating mates, searching for prey, avoiding predators and hazards, and for short- and long-range navigation. Noise at inappropriate volume and frequency can mask biologically relevant signals; it can lead to a variety of behavioural reactions; and, at very high levels, earing organs can be adversely affected and in extreme circumstances, sound can injure or even kill marine life. The total amount of man-made sound has been increasing globally and is likely to go on increasing in Scottish waters in association with increasing offshore industrial activity. Sound produced at low frequencies could have effects well beyond Scottish waters.

Sound sources of primary concern are explosions, shipping, seismic surveys, offshore construction and offshore industrial activities and sonars of various types, including military sonar, which has previously been implicated in deaths of beaked whales. The cumulative effects of many different sound sources are difficult to predict but are likely to be a challenge to some marine wildlife.