Abstract
The Biscay Marine Energy Platform ( bimep ) is an offshore infrastructure for the demonstration and testing of wave energy harnessing devices promoted by the Basque Entity of Energy (Ente Vasco de la Energía - EVE). Bimep is located close to Arminza town (Basque Country, Nor thern Spain) and it consists on an 5.3 km 2 sea area between 50 and 90 m depths where four static submarine cables will be placed, operating at 13kV and 5MW. On the first of June 2009, the General Council on Environmental Quality Assessment of the Ministry of Rural, Marine and Natural Environment of the Spanish Government, on the light of the Environmental Impact Study (EIS) of the bimep project undertaken by AZTI in 2008, decided not to submit the project to the whole Environmental Impact Assessment (EIA) process. Nevertheless, the Environmental Impact Statement (EISt) of the Ministry, taking into account the great uncertainties about some predicted environmental impacts, underlined the need to implement the proposed Environmental Monitoring Program (EMP) o f the EIS. Among other environmental factors, an increase in noise from shipping activity would be expected during installation of submarine cable s and consequently may affect marine mammal communities . Hence, on August 29 of 2013, the EVE entrusted to AZTI to carry out the acoustic EMP of the installation of the submarine cables , which consist on an acoustic characterization of : (i) sound background levels ; (ii) cable installation operations; and (iii) a propagation of the measured cable i nstallation sound. The results showed a background level of 70 - 80 dB. The acoustic signal during cable installation is characterized by a 11 kHz frequency and 188,5 dB re 1μPa which is able to affect a 400 km 2 area. Impacts over marine mammal’s communities were not expected due to the temporality, the season and intensity of the installation operations.