Adapt to storm risks with nature-based solutions

In 2024, the world experienced 58 natural disasters (such as floods, wildfires, droughts, heatwaves, and storms) that caused over USD $1 billion in damages each (1). At the same time, Swiss Re estimates that insurance losses from natural disasters are rising at 5–7% annually, reaching USD $145 billion by the end of this year (2). In particular, commercial buildings and infrastructure, ranging from office buildings to production facilities, warehouses, roads and power grids, face increasing exposure to the growing risk of natural hazards. For businesses, this requires shifting from reactive recovery efforts towards proactive prevention strategies.

Research by UNEP has shown that Nature-based Solutions (NbS) - which are defined as actions to protect, conserve, restore, and sustainably manage different types of ecosystems to address business and societal challenges - can reduce the negative effects of natural hazards and simultaneously provide tangible benefits for the implementing business (3). By applying NbS at the landscape level with the involvement of local experts and stakeholders, these solutions achieve their greatest impact in terms of cost savings and protection potential against natural hazards.

Van Oord is a Dutch marine contractor specializing in dredging, offshore wind, and coastal restoration. In 2020, the company launched Ocean Health, an initiative designed to turn climate and nature commitments into tangible action. Through Ocean Health, Van Oord supports energy companies in safeguarding coastal and offshore infrastructure from storm-related damage through the installation of oyster reefs.

As the company expands its work in renewable energy—particularly offshore wind—it increasingly integrates Nature-based Solutions (NbS) to enhance marine biodiversity and mitigate the impacts of climate change. For coastal infrastructure, oyster reefs have proven effective in reducing storm impacts and supporting intertidal ecosystems. While the same claim cannot yet be made for offshore assets, oyster reefs can form an integral part of scour protection systems, helping to stabilize seabed conditions and secure offshore foundations of wind farms.

Around 150 years ago, oyster beds blanketed an estimated 20 to 30 percent of the Dutch North Sea floor. These rich ecosystems once provided habitat and food for several species of fish and other marine life, and served as a natural coastal protection for the communities living along the shorelines. However, during the 19th century, oyster populations declined sharply as a result of overfishing, pollution, and disease outbreaks. Today, the seabed has largely transformed into a sandy plain, offering little of the hard substrate that oysters need to settle and grow.

Figure 1: Piscatorial Atlas showing the original distribution of the European flat oyster in the North Sea (Olsen, 1883).

Van Oord’s RESO project is executed by a 9-party consortium (more in section ‘Stakeholders involved’) and aims to demonstrate new techniques to restore native European flat oyster reefs in the North Sea. The project brings together hatchery production of flat oysters, innovative settlement technology, offshore engineering expertise, and robust ecological monitoring to deliver a scalable, replicable solution for boosting biodiversity and enhancing storm resilience.

The process begins in a hatchery, where adult oysters (broodstock) are conditioned to produce millions of larvae. Environmental parameters such as temperature, salinity, and feeding rates are closely monitored to optimise larval health and settlement potential. These larvae are the foundation of the nature restoration project that will later be deployed in coastal and offshore sites.

Once larvae reach settlement stage, they are transferred to a remote-setting facility - a mobile, containerised unit that allows oyster larvae to attach to rock substrates under controlled conditions. This modular, containerized setup allows flexible scaling and on-site production near deployment areas, reducing logistical costs and biosecurity risks.

Inside each container, rocks are placed in temperature-controlled seawater tanks enriched with algae to promote settlement. Within days, the larvae firmly attach to the hard substrate (in this case: the rocks), forming so called ‘spat-on-rock units’ - each containing several of juvenile oysters that will continue to grow after deployment.

Figure 2: Adult oysters are placed in a hatchery (left), where they produce large amounts of larvae. This larvae is then placed in a containerized unit with rocks, to create ‘spat on rock’ – larvae that has attached the hard substrate.

The spat-on-rock is then deployed using offshore-certified placement methods, adapted from Van Oord’s dredging and installation operations. Two main techniques are used: Rock bags, which unfold upon contact with the seabed, and tipping baskets, which release material with controlled precision. The first coastal deployment took place in Alexiahaven, Port of Rotterdam, where approximately 9 tons of rock covered with spat-on-rock were placed. Each ton hosted tens of thousands of oysters - together representing around half a million individual oysters. Future offshore deployments, for example for a wind farm in the Dutch North Sea, plan to scale this up to about 18 tons of material per site.

Figure 3: Oyster larvae are outplaced in the port of Rotterdam via a tipping basket (right). In the future, larvae can also be outplaced to protect monopiles of wind parks (left)

A comprehensive monitoring framework ensures scientific rigour and adaptive management. Pre-deployment surveys record larval settlement rates and initial coverage per rock. Assessments are carried out six months and one year after deployment to evaluate oyster survival and growth. Full-year evaluations include ROV (remotely operated vehicle) surveys and underwater photography to map reef structure and coverage. This process helps quantify ecological and engineering performance (e.g., survival rates, species diversity). The monitoring data is then fed into a central repository shared with the public, as well as partners and universities, who can then identify and recommend improvement areas for future projects.

A key innovation of RESO is its ambition to integrate living reefs directly into coastal and offshore infrastructure. Oyster reefs can serve as natural scour protection around monopiles and foundations of offshore wind farms, or to protect offshore cables from scour. This hybrid approach of combining “grey and green” infrastructure allows companies to strengthen asset protection while contributing to biodiversity restoration targets and regulatory requirements.

If the first projects prove to be successful, the model will be scaled up and replicated across European ports, wind-farm zones, and wider seascapes in the North Sea.

Figure 4: To scale up this solution, flat oysters can be installed across current and upcoming wind parks in the North Sea to protect monopiles from storms.

Sustainability Impact

Climate Impact

Oyster reefs absorb wave energy, reducing the height and velocity of storm-driven waves before they reach the shore or coastal structures. This natural buffering helps protect ports, energy assets, and coastlines from erosion and flooding. The reefs also stabilize seabed sediments, reducing scour and erosion which could destabilize the foundation of wind turbines. In addition, oyster reefs sequester small amounts of nitrogen in their shells and surrounding sediments, contributing modest but measurable climate mitigation benefits.

By integrating reef restoration into storm and scour protection, the project enhances long-term resilience under climate scenarios that project stronger storms and higher sea levels.

Nature Impact

In contrast to the current ‘sandy’ seascape in the North Sea, oyster reefs provide complex, three-dimensional habitats that support a wide range of marine species. The restored reefs attract fish, crabs, and other native species as a natural shelter, boosting local biodiversity and consequently the productivity of local fisheries.

As so-called ‘filter feeders’, oysters improve water quality by removing suspended particles and excess nutrients in the water, increasing light penetration and promoting seagrass and algae growth.

Moreover, the restoration of native oyster reefs can contribute to stabilizing seabed sediments and reducing erosion, which ultimately contributes to healthier coastal ecosystems that are better able to adapt to future climatic pressures.

Social Impact

Next to the climate and nature benefits, oyster restoration projects can enhance local livelihoods by creating employment opportunities in oyster production, reef monitoring, and marine restoration. Cleaner water and restored coastal ecosystems contribute to improved community well-being, as well as higher fisheries yields in these seascapes.

When employed in coastal areas, these flat oyster reefs act as a natural breakwater – reducing wave intensity and thereby protecting the shoreline from heavy storm impacts. Finally, the collaboration between industry, academia, and NGOs strengthens knowledge exchange and helps foster a broader cultural shift toward restorative marine infrastructure.

Business Impact

Business Benefits

The project demonstrates how living reefs can deliver tangible business value for companies that depend on resilient marine environments and coastal infrastructure. By restoring oyster reefs as natural infrastructure, businesses can strengthen the long-term resilience of their assets, reduce maintenance costs, and contribute to ecosystem recovery.

One of the most immediate benefits lies in reduced maintenance costs. Oyster reefs function as living breakwaters, dissipating wave energy and mitigating coastal erosion. For industries such as ports, offshore wind, and other coastal operations, this natural buffering reduces the frequency and severity of storm damage – especially to coastal infrastructure. Over time, this leads to lower maintenance and repair expenditures, as well as improved operational continuity in the face of increasingly intense storm events.

In addition, the restoration of native oyster reefs is a Nature-based Solution for scour protection, a key challenge for offshore wind farms and other marine structures. Traditional scour protection relies on large volumes of mined rock placed around turbine foundations to prevent erosion caused by water currents. Living reefs offer a regenerative alternative: by stabilizing sediments through shell accumulation and biological activity, they naturally protect foundations from scouring. This reduces lowers procurement and transport costs, and enhances the sustainability performance of projects — an increasingly important factor in infrastructure tenders and environmental, social, and governance (ESG) assessments.

From a reputational standpoint, the integration of nature restoration into core business operations strengthens a company’s brand and license to operate. Demonstrating measurable contributions to marine biodiversity and ecosystem recovery supports corporate commitments to sustainability and nature-positive outcomes, while reinforcing stakeholder trust among regulators, local communities, and investors.

At the same time, embedding living reef restoration within offshore or coastal projects can provide a competitive advantage in procurement processes. Many tenders for renewable energy and marine infrastructure projects now include sustainability scoring criteria. By incorporating ecosystem co-benefits — such as habitat creation, carbon sequestration, and water quality improvement — companies can differentiate themselves and improve their standing in competitive bids.

Costs

Implementing oyster reef restoration projects requires an initial investment in oyster spat production, hatchery operations, and remote setting facilities to grow oysters. Additional costs are associated with the site selection and monitoring of the oyster restoration projects. However, these expenses can be strategically offset by integrating reef deployment into existing maintenance and inspection campaigns for offshore wind farms or coastal infrastructure, minimizing additional logistical costs.

Over time, the investment delivers measurable financial and operational returns. If this oyster restoration project will provide evidence that oysters reduce the need for traditional hard-engineering solutions such as ‘rock armoring’ or ‘artificial scour protection’, companies could achieve long-term savings in both material and maintenance costs. Moreover, the restored reefs provide continuous ecosystem services. such as sediment stabilization and water filtration, that enhance asset longevity and resilience, generating value well beyond the initial implementation phase.

Impact beyond sustainability and business

Potential side-effects

Operational challenges include ensuring high survival rates of oysters post-deployment and managing biosecurity risks associated with larval transport. Offshore deployment logistics — such as vessel availability, weather windows, and ROV capacity — also influence costs and timelines.

Furthermore, integrating living reefs into active ports and wind farms requires close coordination with regulators and operators to balance safety, navigation, and ecological goals.

Typical business profile

The approach is relevant for ports, offshore wind developers, coastal infrastructure owners, and marine engineering firms operating in storm-prone or erosion-sensitive coastal regions. These organizations can integrate oyster reef restoration into existing maintenance and investment programs to reduce risk, meet biodiversity goals, and gain a competitive advantage in procurement processes for sustainable operations.

Approach

1. Conduct climate and physical risk assessments for coastal and offshore assets.

2. Produce oyster larvae in hatcheries and prepare settlement-ready rocks in remote-setting facilities.

3. Deploy spat-on-rock using offshore-certified methods (rock bags, tipping baskets, etc.).

4. Monitor survival, growth, and ecological outcomes through underwater photography and ROV surveys.

5. Share results and methodologies across ports, energy companies, and research partners to scale adoption.

Stakeholders involved

The RESO project is delivered through a nine-party consortium that brings together expertise from five different sectors, each contributing unique capabilities to advance large-scale oyster reef restoration in the North Sea.

Van Oord, acting as the marine contractor, leads the execution of restoration works and provides the necessary offshore infrastructure for remote oyster setting. The Port of Rotterdam supports the initiative by offering facilities for remote setting and exploring how oyster restoration can be integrated into existing port infrastructure. TenneT, as the grid operator, contributes by managing the energy infrastructure and facilitating connections between offshore activities and coastal operations.

From the academic sector, Wageningen Marine Research, Wageningen University & Research, and Waardenburg Ecology play a key role in scientific research, monitoring, and evaluating the health and ecological impact of the restored oyster reefs. Meanwhile, the participating NGOs - ARK Rewilding, Stichting Zeeschelp, and The Rich North Sea - collaborate on refining restoration techniques, sharing results, and ensuring that ecological and societal benefits are effectively communicated to broader audiences.

Together, these partners form a cross-sector alliance working to restore marine biodiversity and strengthen coastal resilience.

Key parameters to consider

Species depth tolerance, substrate stability, water quality, permitting processes, long-term monitoring requirements, and the technical feasibility of integrating living reefs into engineered infrastructure.

Implementation and operations tips

Generally, based on guidance and experience from leading organizations such as the International Union for Conservation of Nature (IUCN), the World Resources Institute (WRI), and Arcadis, several critical success factors have been identified for corporate implementation of NbS:

Address a business challenge directly: NbS must be framed as part of a company’s business solutions toolkit to drive investment and adoption. For example, NbS designed for heatwaves can deliver measurable resilience benefits to the implementing business, as illustrated in this case study.

Deliver multiple benefits: NbS inherently provide biodiversity gains while contributing to climate mitigation and offering societal benefits. With limited sustainability budgets, prioritizing projects that deliver multiple outcomes increases their attractiveness to companies.

Implement at a landscape level: Deploying NbS across a landscape maximizes their effectiveness and cost efficiency, enabling collective resilience that protects multiple stakeholders from natural hazards. Therefore, upscaling NbS is crucial.

Accurately value benefits: Proper valuation should capture avoided losses, operational savings, and enhanced asset value, which strengthens the case for private investment and ensures long-term maintenance and sustainability.

Leverage technical and local expertise: Successful NbS implementation depends on technical know-how, thorough planning, and understanding of local environmental conditions. Working in a multistakeholder, landscape-level context requires strong project management, stakeholder coordination, and potentially support from funding partners to overcome long lead times and landscape-specific challenges.

By focusing on these success factors and integrating monitoring, cost-effective resource use, and holistic benefits evaluation, companies can overcome implementation challenges, drive adoption at scale, and ensure the long-term operational success of Nature-based Solutions.