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, Northern Spain) and it consists on an 5.3 km2 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 undertak en 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 envi ronmental impacts, underlined the need to implement the proposed Environmental Monitoring Program (EMP) of the EIS. Among other environmental factors, substratum alteration was foreseen to occur during the commissioning stage of the submarine cables and co nsequently may affect related benthic habitats and species. Hence, on August 29 of 2013, the EVE entrusted to AZTI to carry out the EMP of the installation of the submarine cables in bimep , which consist on: (i) a seabed characterisation with a multi - beam echo sounder ; (ii) a characterization of benthic communities and seabed disturbance by means of a visual inspection with a submarine camera attached to a Remote Operated Vehicle (ROV) all along the submarine cable route and the mooring areas. The results o btained were compared with those obtained during the preoperational phase of the EMP ( carried on 2012 ) , showing that the observed impacts were in the range of those predicted in the EIS of bimep .