Borkum Stones, Voordelta
Restoration Projects

Photo: with copyright

The Netherlands
Borkum Stones, Voordelta

Borkum Stones:

WWF Netherlands is planning to restore Ostrea edulis reefs in the Borkum Stones area. A pilot project is currently being prepared, to start in 2018. In the pilot, 3-D printed reefstructures, other hard substrate material and a starting population of (Bonamia free) Ostrea edulis are to be combined.

ARK and WWF have now released the first report on the pilot project at the Borkum Reef. You can read more and download the full report (in English) here..


Emilie Reuchlin-Hugenholtz
WWF Netherlands


Since 2016, an Ostrea edulis reef restoration project is undertaken in the Voordelta area, off the coast of Zeeland. It is part of the large ‘Dream fund Haringvliet Project’ ( The project is funded by the National Postal Code Lottery Netherlands and lead by Ark Natuurontwikkeling and WWF Netherlands. The work is executed by Wageningen Marine Research, Bureau Waardenburg and Sas Consultancy. When surveying the area to find a suitable pilot location, a mixed Ostrea Edulis/Magellana gigas reef was discovered. The Ostrea coverage varies strongly, but the reef roughly extends over 40 hectares. Most likely, the Voordelta population is offspring of the Ostrea culture in Lake Grevelingen nearby. Because of this discovery, it was decided to re-orient the project from ‘restoring’ to ‘extending’ Ostrae reefs: experiments are undertaken to investigate the mechanism of spatfall, to extend the population and also use the results to ‘kick-start’ Ostrea reefs elsewhere. In line with this, a new pilot location, further offshore, is being planned. The biodiversity of the mixed Ostrea/Magellana bed is investigated in order to show the difference with soft sediment habitat.


Karel van den Wijngaard
Ark Natuurontwikkeling

Check out our reports on VOORDELTA, GEMINI, BORKUM STONES:

  • Sas, H., Didderen, K., Van der Have, T., Kamermans, P., Van den Wijngaard, K., Reuchlin, E. 2019. Recommendations for flat oyster restoration in the North Sea. Synthesis of lessons learned from the Dutch Voordelta experiments, with additional observations from flat oyster pilots in Borkum Reef and Gemini wind farm, modelling exercises and literature.
  • Didderen, K., W. Lengkeek, J.H. Bergsma, U. van Dongen, F.M.F. Driessen, P. Kamermans 2020. WWF & ARK Borkum Reef Ground oyster pilot and Active restoration of native oysters in the North Sea – Monitoring September 2019. Bureau Waardenburg Report no.19-227. Bureau Waardenburg, Culemborg.
  • O.G. Bos, P. Kamermans , M.Schutter, M. Maathuis, A. v Gool, T vd Have, J. Bergsma , T. Raaijmakers , L. v Duren, H. Sas. 2020 Monitorng of oyster bank re storation Gemini Offshore windfarm and Borkum Reef 2019, 
    Progress report Project Ecofriend 2019. Contact Oscar Bos for report. Bos, Oscar
  • Fieldreports Voordelta upon request, please contact Ernst Schrijver

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