This paper provides a general description of the environmental monitoring programme currently ongoing at Vattenfall’s/Tussa’s wave power test site "Maren", on the Norwegian west coast. The purpose of the environmental monitoring is twofold: (i) to monitor the potential impact of the Maren installation on the environment, thereby fulfilling the consent requirements of the Norwegian authorities, (ii) more generally, to gain experiences about the design and management of an environmental monitoring programme and test a variety of monitoring methodologies and equipment. The primary environmental parameters assessed in the monitoring programme include fish, benthos and seabird communities. Observations on marine mammals are included marginally and underwater noise measurements are scheduled to be included at a later stage. The rationale for choosing the specific components of the monitoring programme is elucidated in the context of site specific environmental features, as well as project-specific technical characteristics. Generally, the monitoring strategy follows a modified so-called BACI (Before-After, Control- Impact) design, i.e. takes place before and after deployment of the wave power devices and during operation over a period of approximately 3 years. A communication plan accompanies the programme and is considered an essential prerequisite for transparency and public acceptance of the programme.