RESTORE 3 Upscaling

Integrative Measures for the Restoration of Intact Reef Systems of the European Flat Oyster
Project Duration: 2025–2034

The collaborative project RESTORE 3 aims to achieve the long-term restoration of biogenic reef systems formed by the European oyster (Ostrea edulis) in the German North Sea. Commissioned by the Federal Agency for Nature Conservation (BfN), the project is being implemented by the Alfred Wegener Institute (AWI) in cooperation with the Thünen Institute. Over a period of ten years, existing restoration measures will be further developed, expanded spatially, and scientifically monitored. The objective is to establish functional oyster reefs permanently as valuable habitats within the ecosystems of the German North Sea.

Why oyster reefs?

Oyster and mussel beds are among the biogenic reef types of temperate regions and are considered some of the most threatened marine habitats worldwide. Centuries of intensive fishing led to the near-complete collapse of natural populations of the European oyster throughout Europe during the 20th century.

Oyster reefs are hotspots of biodiversity:
They provide food, shelter, and settlement substrate, function as spawning and nursery grounds, and stabilise the surrounding ecosystem through their three-dimensional structure. In addition, they improve water quality through filtration, bind sediments, and contribute to increasing the ecological value of the seabed.

Project objectives

RESTORE 3 builds upon the extensive preparatory work and findings of the BfN-funded projects RESTORE and PROCEED and also benefits from close collaboration with the Native Oyster Restoration Alliance (NORA). These initiatives have established essential foundations for the active restoration of biogenic reefs — ranging from the identification of suitable restoration sites and monitoring methods to the sustainable production of oyster spat. The project focuses on scaling up proven restoration measures:

• Spatial expansion of existing pilot oyster reefs in Borkum Reef Ground
• Establishment of a pilot oyster reef in Sylt Outer Reef
• Expansion of oyster cultivation and oyster spat production
• Broadening of target species: reintroduction of oysters and stock enhancement of associated species
• Scientific support and monitoring
• Enhancement of ecosystem functions and biodiversity

In addition to the European oyster as a key species, further groups of organisms will also be specifically incorporated. These include mesopredators such as the European lobster, as well as top predators such as skates. The aim is to restore stable, functioning reef ecosystems with high biodiversity and essential ecosystem services.

The measures will be implemented within the Natura 2000 sites of the German Exclusive Economic Zone (EEZ) in the Borkum Reef Ground and Sylt Outer Reef areas, thereby making a significant contribution to the implementation of marine conservation management and compensation measures.

RESTORE 3 makes an important contribution to active marine conservation and to the long-term restoration of valuable habitats in the German North Sea.