The effects of anthropogenic underwater noise on different marine species is open to study and debate, as it is a source for tension between and within sea users’ (e.g. fishermen, shipping companies, energy companies, etc.), scientists and politicians. This paper aims at identifying and circumventing environmental constrains for better characterising sound emissions from various marine energy converter (MEC) types deployed on both wave and tidal sea-trial test sites. This study benefits from the collaborations of the scientific operators of marine energy sites from Spain (AZTI) and France (Energie de la Lune). Several underwater acoustic measurement campaigns were conducted on Biskay Marine Energy Platform (BIMEP) and SEENEOH tests sites and Mutriku Oscillating Water Column (OWC) wave power plant. The methodology used for data acquisition relies on both drifting and bottom moored hydrophones thus enabling to characterising both ambient operating noises and comparing two different underwater acoustic equipment. Long and time expensive data post-processing allowed for identifying and circumventing different kind of sound emissions from different origins: anthropogenic sound, site-related noises, and ambient noise. Impulsive and continuous sounds were assessed following criteria compliant with the Marine Strategy Framework Directive (MSFD). Results presented here allow for identifying difficulties in operating with different instrumentation and monitoring methodologies in these harsh environments. Analysis of acoustic samples during MEC operation allowed for identifying impulsive noise sources mainly related with mooring lines of MECs. Collection of device-generated noise during various operating states and seasons, for the purpose of evaluating potential noise impacts on marine organisms of concern is needed for a better understanding and characterization of these potential impacts.
