A lack of consistent widespread information on potential environmental effects, monitoring outcomes, and mitigation strategies continues to hinder the development and deployment of marine energy systems around the world. To address this need, member nations of the Ocean Energy Systems-Implementing Agreement (OES) formed Annex IV, a three-year collaborative effort (2010-2013) to increase knowledge sharing, research collaborations, and efficient regulatory decision-making associated with investigating and evaluating the potential impacts of wave and tidal energy. The efforts of Annex IV resulted in the launching of a publically-available, searchable online database of environmental information (called Tethys), housing scientific literature pertaining to the environmental effects of marine energy systems, as well as metadata on international ocean energy projects and research studies. In addition to providing broad access to information on environmental effects of marine energy development, Tethys can act as a commons for bringing together researchers, device and project developers, regulators, and stakeholders, to explore common interests and information needs for the emerging marine energy industry. This paper will demonstrate the development, existing functionality, and content of Tethys, as well as discuss the future of Annex IV including information updates, improvements, and additional outreach efforts over the next several years.