A consortium of partners in the Netherlands will introduce at least half a million flat oysters into the Port of Rotterdam on September 2 as part of a new pilot project to raise oysters around marine infrastructure, such as wind turbines, breakwaters and subsea cables.
This pilot is aims to restore oyster reefs in the North Sea on a large scale.
Known as the remote setting method, it involves cultivating millions of oyster larvae in a dedicated hatchery before transferring them to a harbor or other location close to the sea. There, they are placed in shipping containers filled with seawater and rocks. In just a few days, the larvae attach themselves to the rocks and then grow into juveniles.
After a few weeks, the shipping containers are loaded onto vessels. Before being installed at sea, the foundations of this infrastructure are covered with juvenile oysters. The rocks bearing the juvenile oysters are released into the sea, where they seek their new habitat.
By incorporating the oyster-bearing rocks directly into the engineering, construction and maintenance of wind farms, subsea cabling, breakwaters, platforms and other marine structures, the consortium members are combining marine infrastructure and large-scale nature restoration.
The partners hope that this modular, flexible design will provide a cost-efficient method to raise oysters and support reef restoration that can be applied anywhere and on any scale. Though some research indicates that leached metals from such installations could harm sea life in the vicinity.
Researchers will spend the next few months monitoring the survival and growth rates of the oysters. Next year, the consortium members plan to test the remote setting method again, at a TenneT cable crossing in open sea.
The consortium is also investigating the influence of reef sounds. Do flat oysters use these sounds to find a suitable habitat for themselves? If so, then the sounds can be used to improve their chance of settling.
‘Thanks to close collaboration, our consortium has been able to deliver and implement a major innovation,” Nienke Oostenbrink – Pilot Lead & Business Developer for Van Oord Ocean Health. “I’m extremely proud of that. It holds promise for scaling up nature restoration in the North Sea and may have a significant positive impact in years to come.”
Oyster reefs
The partners said the push to develop this new method comes from an awareness that marine life in the North Sea is under pressure. Oysters form large-scale subsea reef structures by clustering together over the course of their lifespan. The reefs create a solid bedding full of nooks and crannies that are ideal habitats for numerous types of plants and animals. The oysters also filter the water, release nutrients and absorb waste products. All this makes them a vital factor in sustaining life in the North Sea. The North Sea’s oyster reefs have disappeared almost entirely, however, due to overfishing, pollution and disease. The remote setting method can make a significant contribution to regrowing the reefs.
“Oysters are the silent engineers of a healthy aquatic ecosystem. Restoring the reefs is no luxury, it’s a necessity. I am hopeful that we can restore the reefs using this innovation,” said Vera Bánki, De Rijke Noordzee Programme Director.
The project draws on the expertise of the nine consortium partners: Wageningen Marine Research, Wageningen University & Research, ARK Rewilding Nederland, Stichting Zeeschelp, Waardenburg Ecology, Van Oord Ocean Health, TenneT, Port of Rotterdam Authority and De Rijke Noordzee (a joint venture between Dutch nature conservation organisations Stichting de Noordzee and Natuur & Milieu). The companies, public knowledge institutions and nature conservation organizations that make up the consortium have spent the past three years working together to refine the remote setting method.
