In Belgium, flat oysters used to be abundant and formed large oyster reefs, a valuable habitat supporting a unique marine biodiversity. What used to be a key element of the country’s biodiversity, cuisine and culture, is almost extinct today.
Belgian offshore wind farms might offer a unique environment to interactively restore oyster reefs and develop aquaculture. Bottom fishing is not allowed in wind parks and oyster reefs would thus not be damaged. In addition, the hard substrate used as scour protection around wind turbines may be the perfect substrate for oyster larvae to settle on and initiate natural oyster reefs. Aquaculture could be developed hand in hand with restoration efforts, as the two activities would enhance each other : aquaculture would provide the initial stocking material to help developing natural reefs and in the longer term, natural oyster reefs would provide oyster larvae to the aquaculture sector.
Co-location of restoration and aquaculture in wind parks looks like a logical choice, but we are still far from its large-scale application. The distance from the coast complicates implementation, operation and maintenance of the structures needed for restoration and aquaculture production, and the same can be said about the harsh sea and weather conditions in the North Sea. Optimal growing conditions of flat oyster are quite specific, and this makes offshore aquaculture and restoration very challenging. The selected scour material must fulfill the technical requirements imposed on scour material in general and, at the same time, it should creat ab attractive habitat for oyster larvae to settle.
The Belgian pilot, being one of the 5 demonstration pilot of the European funded Horizon2020 project “United” (https://www.h2020united.eu/) is addressing these challenges by finding the best technical and managerial solutions in a pilot wind farm within the designated zone for offshore wind in the Belgian offshore space (exclusive economic zone). Models to correctly position the longlines are applied, proper systems for spat collection and grow-out are being developed, and several scour protection materials are being tested. In addition, the Belgian pilot is combining the culture of flat oyster and sugar kelp, and compares the characteristics of sugar kelp grown nearshore and offshore.
Industry: Jan De Nul, Brevisco, Colruyt, Parkwind
Research institutes: UGent (Pilot leader), ODNature
Dr. ir. Nancy Nevejan
Dr. Annelies Declercq