The Offshore Wind farm Egmond aan Zee (OWEZ) was built between April and September 2006 and has been in operation since January 2007. As part of an extensive Monitoring and Evaluation Program (NSW-MEP), Bureau Waardenburg was commissioned to describe the development of benthic communities on hard substrates (monopiles and scour protection layer) within OWEZ. The first qualitative and quantitative assessments were carried out in February and September 2008 and were reported in Bouma & Lengkeek (2009). In 2011 these assessments were repeated in the same months, selecting the same turbines and using the same methods as in 2008. This report presents the results of the 2011 assessments and provides a comparison with the results of 2008.
In February and September 2011 additional information was gathered on the presence of benthic species in scour holes that are present at the edge of the scour protection layers of the turbines. Furthermore, additional samples were collected in September 2011 in order to determine the particle sizes of the sediment in these holes. These results are also included in this report.
For this study three turbines were selected to cover different distances from the shore and different areas within the OWEZ: turbines 7, 13 and 34.