IMIS

In the framework of the assessment of the effects of the construction and operation of offshore wind farms on small cetaceans, the RBINS uses Passive Acoustic Monitoring Devices: porpoise detectors (C-PoDs and F-PoDs). The detector consists of a hydrophone, a processor, batteries and a digital timing and logging system, and has an autonomy of up to four months (www.chelonia.co.uk). Data obtained provide an indication of the presence of harbor porpoises in the vicinity of the device, up to a distance of approximately 300 m. Data obtained from one PoD can give an indication of presence/absence of porpoises, and can be compared to data obtained from PoDs moored at other locations – as such, the presence of porpoise in wind farm areas can be compared to the presence of porpoises in reference areas as well as compared throughout the year.