The construction and operation of marine renewable energy developments (MREDs) will lead to, among other things, the emission of electromagnetic fields (EMF), underwater sound, and vibrations into the marine environment. Knowledge on these pressures and associated effects has been increasing over the past decade. Yet, many open questions with regard to the potential for MRED to impact on marine life remain. These information gaps pose challenges to the planning and deployment of MREDs. To address this, the European Union (EU) Commission, Directorate-General for Research and Innovation commissioned a study of the environmental effects of noise, vibrations and electromagnetic emissions from MREDs (Marine Renewable Energy, Vibration, Electromagnetic fields and Noise - MaRVEN). MaRVEN provides a review of the available literature related to environmental impacts of marine renewable energy devices and an in-depth analysis of studies on the environmental effects of noise, vibrations and electromagnetic emissions during installation and operation of wind, wave and tidal energy devices. The current norms and standards related to noise, vibrations and EMF were reviewed. On-site measurements and field experiments to fill priority knowledge gaps and to validate and build on the results obtained in reviews were undertaken. Finally, we outline a programme for further research and development with justified priorities.