The new European Climate Plan, launched in 2008, imposes upon each member state a target contribution figure for the production of electricity from renewable energy sources that should be achieved by 2020. For Belgium, this target figure is 13% of the total energy consumption, part of which will be realised in offshore waters. To allow for a proper evaluation and auditing of the environmental impacts of offshore wind farms, the environmental permit includes a mandatory monitoring program to ensure (1) the ability to mitigate or even halt the activities in case of extreme damage to the marine ecosystem and (2) an understanding of the environmental impact of offshore wind farms to support policy, management and design of future offshore wind farms. The former objective is basically tackled through the baseline monitoring, focusing on the a posteriori, resultant impact quantification, while the latter monitoring objective is covered by the targeted or process monitoring, focusing on the cause-effect relationships of a priori selected impacts. As such, the baseline monitoring deals with observing rather than understanding impacts and hence leads to area-specific results, which might form a basis adjusting existing activities (or even halting activities, in case of extreme environmental damage). Targeted monitoring on the other hand deals with the understanding of the processes behind the impacts and hence leads to more generic results, which might form a sound basis for impact mitigation. The monitoring program targets physical (i.e. hydro-geomorphology and underwater noise), biological (i.e. hard substratum epifauna, hard substratum fish, soft substratum macrobenthos, soft substratum epibenthos and fish, seabirds and marine mammals), as well as socio-economic (i.e. seascape perception and offshore renewables appreciation) aspects of the marine environment. The first phase of the monitoring program started the year before the (anticipated) construction of the first wind turbines at the Thorntonbank (i.e. 2005). At the end of this first phase (2005-2012), an overview and discussion of the monitoring activities and outcomes between MUMM, its monitoring partners and the wind farm industry is planned. This workshop will be the first thorough evaluation of possible impacts of marine wind farms in Belgian waters.