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.
Two observers are on board the vessel; one conducting the visual observation – the other operating the PAM equipment. The MMO conducting visual observation is located at an observation height of 5m and with a 360 degree view.
The PAM equipment consists of four custom-made hydrophones arranged in a linear towed array deployed approximately 20-50m behind the vessel. Computers on board the vessel interpret the data and present it visually on a screen for the observers.
The MMO vessel is circling the construction vessel prior to piling, and when no marine mammals have been observed for 30 minutes, piling can initiate. The observations will continue throughout the piling, and any animals approaching closer than 500m during piling will be noted as animals entering voluntarily.
The Walney Offshore Windfarm
The Walney Offshore Windfarm project is located approximately 15km west of Barrow-in-Furness in Cumbria. The project consists of Walney 1 and Walney 2 each with 51 – 3.6MW turbines, giving a total capacity of the Walney project of 367.2MW. The rotor diameter of the turbines is 107m for Walney 1 and 120m for Walney 2, with a maximum height of 150m from blade tip to sea level. The total area of the development is some 73km2.
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Source: dongenergy, June 21, 2011