Off the Dutch coast, a biomaterial is bringing wildlife back from the brink.
In 2024, researchers left biobased concrete in the Yerseke mudflats. Within a year, they were covered in oysters, mussels, and algae – species that have been on the decline in the area.
Organised by researchers at the Royal Netherlands Institute for Sea Research, the experiment proved biomaterials could replace concrete in coastal restoration.
Biomaterials like this could become a bigger part of habitat restoration across Europe. There, new laws are pushing countries to rebuild landscapes that offer protection from climate impacts.
Here is how renewable materials can rebuild ecosystems from the ground up, sustainably.
Restoring the wild
The Netherlands are rich in salt marshes and mudflats. These bleakly beautiful landscapes are deeply embedded in the cultural imagination, so much so that there is a Dutch word for the act of walking across them: “wadlopen”.
Over the centuries, the Dutch wetlands have been systematically drained for agriculture and settlement. Now, these wild spaces are becoming the target of restoration efforts.
There are economic reasons behind the wetland restoration. As a low-lying country, the Netherlands is particularly vulnerable to climate impacts like flooding and sea level rise. Wetlands will be the first line of defence against increasing storms and coastal erosion.
Rebuilding the coast
Coastal restoration is a formidable task. It often involves constructing new areas of land either as anchors for wildlife or as buffers against erosion.
Concrete is the standard material for its strength and durability. Yet it has major drawbacks from a conservation perspective.
Concrete is incredibly carbon intensive to manufacture, increasing the environmental costs of restoration projects that use it. Heavy metal leaching is another concern with this industrial material. It is also difficult to mould into custom shapes for specific conservation tasks.
Its lack of biodegradability is another concern for projects that do not require permanent structures in the landscape.
In the Yerseke experiment, a biobased concrete called Xiriton replaced conventional concrete. Made of grass, pozzolan, slaked lime, shells, sand, and seawater, these solid blocks are a cheap and ecological alternative for coastal restoration.
Grass replaces concrete
Not only is it made from many abundant natural resources, Xiriton overcomes many of the limitations of concrete.
Biobased concrete is easier on the environment because it releases far fewer carbon emissions to manufacture than normal concrete. It is also less alkaline than normal concrete, which makes it more appealing to wildlife.
The biggest advantage that Xiriton has over conventional concrete and synthetic plastic is that it is rapidly biodegradable.
Researchers were even able to control when the material would start degrading – in this one case year – by adjusting the drying time or the amount of binder they added to the concrete mix.
The ability to adjust when a material begins to recompose can be all-important in ecological projects, where material life-spans must adapt to the rhythms of the natural environment.
This was a priority in the Yerseke experiment, where the Xiriton blocks were only meant as temporary footholds. The aim was to attract enough wildlife so that the habitat could eventually grow out in a self-sustaining manner.
Other projects, however, may demand longer lasting materials. Reconstructing large areas of the coast to ward off erosion would require structures that lasted decades, not months.
Xiriton has not yet been tested in the field along these timescales. However, the tests conducted so far show that the natural concrete can be incredibly durable, including under sustained wave action.
All in all, this bio-concrete combines the versatility of plastic or concrete with the biodegradability of all-natural materials – an unusual mixture of properties that make it ideal for extended use in natural environments.
Potato waste honeycombs
Salt marshes are another iconic Dutch habitat where restoration efforts are underway.
A major actor in salt marsh regeneration is the Dutch environmental consultancy Bureau Waardenburg. The company has developed a biodegradable material from potato wastes designed specifically for conservation projects in the salt marshes.
Bureau Waardenburg’s sister company BESE uses the waste-based polymer to make scaffolds that help rebuild these fragile habitats. One of these is a 3D hexagonal frame known as “potato mats”.
Resembling intricate honeycombs, BESE’s potato mats are placed around the marshes, offering shelter and anchorage for aquatic plants and shellfish.
Oyster reefs and vegetation provided these functions before they were destroyed by human activity. BESE’s artificial structures are meant as temporary substitutes that can kickstart the natural reef-building process.
The honeycomb structure of BESE’s frames is not an aesthetic choice. Rather, it is designed to get vegetation growing in a way that maximises its benefits as anti-flooding infrastructure.
The more sediment and salt that salt marsh plants are able to trap, the quicker they can create a physical barrier against incoming storm surges.
BESE’s frame encourages aquatic plants to grow in optimal patterns that scientists believe maximises their particle trapping – and therefore anti-erosion – capabilities.
Traceless structures
Like in the Xitiron experiment off the Belgian coast, BESE’s structures last only as long as it takes for wildlife to re-colonise the area.
Plastics are usually the first choice when it comes to manufacturing intricate structures like BESE’s scaffolds. This is because few materials can match them on mouldability.
Yet most modern plastics do not degrade easily or safely in nature. BESE’s material unites biodegradability with mouldable precision, making it ideal for conservation uses.
Within conservation, it is important to define precisely what biodegradability means. How long a material lasts in the environment can make or break the effectiveness of a project.
BESE’s materials are certified as industrially compostable. This means they meet that microorganisms can break them down in the highly controlled conditions of a composting facility within 6 months.
In addition, BESE has conducted their own field trials to show that its material breaks down in natural conditions as well.
Yet biodegradability varies dramatically between different natural environments. For the BESE material, it ranges from 2 to 4 years in tropical locations and 10 to 20 years in the colder climate of Northern Europe.
The company is actively scoping new biomaterials that degrade more quickly in saltwater habitats, even in colder conditions. The microbially-produced bioplastic PHA is first in line for testing. These are known as the biopolymers that break down most readily in seawater.
Right now, BESE says it’s still searching for high volume, high quality PHA supply made from sustainable waste inputs it can use to make new products. As is typical in the bioeconomy, supply bottlenecks rather than technical performance is what holds back wider adoption.
A new market
By strengthening its wetlands, the Netherlands are preparing its economy for a future of more volatile weather. Other countries are preparing to do the same.
In August 2024, the European Nature Restoration Law entered force. It is a legally binding framework for member states to restore 20% of the bloc’s land and seas by 2030. EU countries will have to draw up and implement plans for where and how they are going to fulfil these objectives.
The law appears to favour rewilding, an approach to nature restoration that allows ecosystems to return to a state it was before industrial development or cultivation.
The concept of rewildling also permeates the EU’s wider Biodiversity Strategy, which the Nature Restoration Law supports. The strategy sets binding targets to restore degraded ecosystems, particularly those that reduce impacts of natural disasters.
Biomaterials like the ones being trialled in the Netherlands could become crucial to these projects. In particular, they offer a light-touch tool to implement rewilding – a passive way of getting nature to a state where it can rebuild on its own.
By offering temporary, non-toxic placeholders for vegetation and wildlife, biodegradable biomaterials kickstart self-sustaining ecosystems in a way that keeps human intervention in fragile habitats to a minimum.
Biomaterials that support biodiversity
We normally think of biomaterials as tools to bring down carbon footprints in industry. Yet Dutch trials in eco-restorative biomaterials show they have enormous benefits for biodiversity and climate adaptation too.
The key to their success is biodegradability. Unlike concrete or synthetic materials, these biomaterials break down in the environment quickly, letting nature take over the work of habitat restoration.
The properties of these biomaterials can also be custom-engineered. They can be adjusted to degrade at certain times or be shaped in ways that serve specific applications.
The next step for the field is developing the ability to control biodegradation rates more precisely. BESE is already experimenting with PHA to develop next-gen bioplastics that break down more reliably in very different habitats.
Low carbon manufacturing, climate policy, and biodiversity protection intersect in eco-restorative biomaterials. Made from abundant local materials, in some cases produced as waste byproducts, these materials could be the future of nature protection in Europe.
The post How bio-concrete and potato plastic is saving the Dutch wetlands appeared first on World Bio Market Insights.
- Source: https://worldbiomarketinsights.com/how-bio-concrete-and-potato-plastic-is-saving-the-dutch-wetlands/
