Concrete increases durability when 'feeding' marine life

Startup Israel develops eco-friendly concrete that becomes even stronger when marine life clings to the surface.

Rising sea levels are causing the need for flood protection measures to increase. However, concrete, the main material used in many man-made retaining walls, can greatly affect marine life and the climate. In order to make coastal structures more sustainable and environmentally friendly, Israeli startup EConcrete develops products that can reduce carbon emissions and attract marine life.

The EConcrete blocks simulate the shape and surface texture of rocks to help marine life cling to. (Photo: EConcrete)

Coastal concrete works bring many benefits to people. However, a lot of marine life also lives near the shore and these man-made structures can destroy their ecosystems. "70% of the world's coastal structures are made of concrete," marine ecologist Ido Sella, co-founder and CEO of EConcrete, told CNN on Wednesday.

Concrete can leach chemicals that make the surrounding water more alkaline and make it harder for some marine life to live. The flat, smooth surfaces of structures such as breakwaters also make it difficult for marine life such as algae, oysters and barnacles to cling to.

EConcrete manufactures admixtures that can be mixed with concrete, making the material better chemically balanced with seawater. The company also manufactures retaining wall blocks that mimic the shape and texture of sea rock. They have tiny grooves in the surface for larvae to attach and grow, undulating sides and shallow depressions that trap seawater like small tidal pools.

ECOncrete products have been installed in more than 35 locations around the world over the past 8 years, including New York, Rotterdam and Monaco. They can more than double the biodiversity of conventional concrete, says Sella. This allows the next generation of organisms to grow on the concrete surface and attract other organisms, kicking off a self-sustaining ecosystem.

Conventional concrete not only harms marine life, but also emits large amounts of carbon. Cement, a component of concrete, contributes to 8% of the world's carbon emissions. EConcrete says its additives reduce the amount of cement needed in the concrete mix, thereby reducing the amount of carbon. However, some ecologists warn that man-made structures cannot completely replace the ecological benefits of natural shorelines.

Surface-dwelling organisms can help make EConcrete concrete stronger over time. They cover concrete with a layer of calcium carbonate, one of the main components of snail shells, preventing the concrete from cracking and increasing its tensile strength by 10 times. The new material is 15% more expensive than traditional concrete but will save money in the long run as it doesn't require much maintenance.