Artificial reefs | Flanders Marine Institute

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Artificial reefs

Two artificial reefs, installed in offshore wind farms on the Belgian part of the North Sea, will be monitored in the framework of the project 'North Sea Observatory'. Soon, a monitoring network will be operational in order to evaluate their potential to increase biodiversity.

When offshore wind farms are constructed, it is necessary to preserve and wherever possible reinforce the natural habitat, e.g. by creating artificial reefs and seal haul-out sites. Two artificial reefs, each existing out of 33 reef balls, were sank in August 2013 nearby the offshore wind parks of the companies Belwind and C-power. The impact of these artificial reefs will be monitored by means of an extensive monitoring network. The installation of the seal haul-out sites will follow in a later phase. A semi-automatic sea observation station that will be consultable online will be set up in order to actively involve the general public in these developments.

The monitoring network will consist of the following equipment installed on a buoy nearby the artificial reef at C-power wind park:

  • a CTD for continuous measurement of the temperature and salinity supplemented with sensors for measuring the turbidity, the dissolved oxygen rate and the seawater productivity;
  • a transceiver system based on acoustic telemetry to monitor the behaviour and movement patterns of fish around the artificial reefs;
  • porpoise detectors to register and monitor the presence of harbour porpoises and other dolphins over time;
  • an underwater camera to monitor the use of the artificial reef balls by fish, marine mammals, lobsters and crabs;
  • a underwater camera to register the use of reef balls by fishes, marine mammals, lobsters, etc.

In March 2014 VLIZ and Ghent University divers explored the artificial reefs on the Thornton bank for the first time. Eight months after installation many organisms already found their way to the concrete reef structures. Among them several crab species, sea anemones, starfish, fish and even a lobster. These first sightings are indicative for the harbour function of the reefs for both mobile and sessile organisms. Have a look at the images in the picture gallery.

The North Sea observation station will be fully operational by the end of 2014. It will be part of the ‘Actieplan Zeehond’ (seal action plan) launched by the Belgian Minister for the North Sea Johan Vande Lanotte. It will be funded by the Belgian Lottery as part of the ‘Sustainable Development’ call. The Flanders Marine Institute will conduct the semi-automatic measurements in close cooperation with Ghent University, the Research Institute for Nature and Forest, the Directorate Natural Environment (RBINS) and the wind farm operators.

For more information, contact Jan Seys.

Related press release: Artificial reefs in the North Sea show good prospects for biodiversity