Offshore Renewables

Noise from piling of monopiles may impact marine mammals and cause disturbance or even injury to animals appearing close to the piling. Therefore, a vessel with marine mammal observers (MMO) is in place during each piling to ensure a ‘marine mammal free’ sea for a radius of 500m from the piling location. This is done by visual observation in combination with applying Passive Acoustic Monitoring (PAM) equipment.

The frequency range, call type and vocal behaviour of cetaceans varies enormously between species and this affects the degree to which PAM provides additional detection power, especially in the noisy environment of a seismic survey.   This system has proven very effective in detecting small odontocetes and sperm whales. PAM is particularly effective for the detection of sperm whales as they can be heard at significant ranges (several miles) and are consistently vocal for a large proportion of the time. Smaller odontocetes such as dolphins, killer whales, pilot whales and other “black fish” can be detected at useful ranges from both their whistle and click.