In the oceans, concrete is the main construction material, accounting for more than 70% of coastal and marine construction such as ports, coastal defense structures and waterfronts. "Concrete is damaging the ocean because, to put it in place, natural ecosystems are destroyed," says Alex Rogers, director of a nonprofit company studying ocean health and raising awareness of global impacts on the marine environment. "Concrete is a conventioal material, and it is low cost. But we should be looking at alternative materials."
Those alternatives might already be here. Among them is a substance called ECOncrete. It produces bio-enhancing concrete products intended to protect coastlines and marine resources. This is achieved by using a mixture made almost entirely of by-products and recycled materials, and is thus nearly carbon neutral. The overall result is a low-carbon concrete.
Furthermore, unlike traditional concrete, which is highly alkaline (碱性的), the specially designed concrete has a PH value near to that of sea water, which helps to promote the growth of marine species such as crabs,clams, mussels, and oysters. ECOncrete is already in use across eight countries and six different areas.
However, Beth Strain, a project leader for Australia's National Center for Coasts and Climate, says the evidence for the concrete as a better surface for marine organisms is very mixed. "It can be location specific. We did an experiment in 13 harbors around the world with the same type of concrete surface complexity. Largely, the results were positive, but in Penang, Malaysia, for example, using the concrete that would theorectically preserve moisture (水分) and be better for organisms to survive made no difference." Strain thinks this is because of the area's typhoons, which make the area very wet already, so the features of the concrete aren't a big help. "There is a degree of difference and each location has its own environmental chanllenges," says Strain.
Nevertheless, from multiple perspectives, it appears that nature-based solutions are definitely the way forward.
