Concrete is all around us. It makes up our sidewalks, our buildings—even our very foundations. We hardly notice it in our day-to-day, but it helps us get around, live comfortably, and flourish.

However, not all forms of life cohabitate happily with concrete. Concrete can be particularly problematic in the marine environment, where it is used in coastal and offshore infrastructure such as jetties, breakwaters, and ports. Many threatened microorganisms such as algae and coral cannot survive on concrete due to its physical and chemical properties. The opposite is true for invasive species, which are adept at colonizing our structures.

It was thought that this problem was intractable—that is, until Dr. Ido Sella and his late business partner, Dr. Shimrit Perkol-Finkel, made a surprising discovery that led to the creation of ECOncrete in 2012. In this conversation with LEFF, Sella (who is also ECOncrete’s CEO) discusses how he and his business partner created a concrete that could help wildlife thrive. Sella also describes how the pair built their business and grew it to achieve positive results around the world. An edited version of the conversation follows.

Claire: How did the idea for ECOncrete come about? What connected the dots between marine life and concrete for you?

Ido: It happened completely by accident; I never thought I was going to deal with concrete. It’s broadly accepted that concrete is not a suitable material for the biological recruitment of larvae, so it’s not usually experimented with.

Here’s one way to think about it: When you look at a fresh concrete wall in your neighborhood, how long will it take for it to develop mosses and lichens? You’re usually only going to see them after years and years of exposure to rain. The same is true for corals, bryozoans [small aquatic invertebrates], or barnacle larvae trying to colonize concrete in the marine environment.

As marine biologists, my partner and I spent 20 years focusing on how coastal and offshore construction in marine environments, such as seawalls, ports, breakwaters, and jetties, affected ecological performance. We did a survey for a client on waterfront assets where we dove along their concrete seawalls and saw the typical scenario of high levels of invasive species, low biodiversity, and algae dominance. But as we swam along the seawalls, in one section we suddenly saw more bryozoans and sessile organisms than usual.

We were lucky that the construction of the seawalls had been carefully recorded. When we brought our findings to the client, he told us that what we had marked lined up exactly with a single casting day. In other words, the area with more organisms had been constructed with one particular batch of concrete.

That was when we started to think that there might be some subtle changes within the concrete mix that might affect biological recruitment.

So we started testing.

Claire: Walk us through the research and development (R&D) process and how you built your business.

Ido: My partner and I came out of academia, so if we’re professional in something, it’s writing grants. We managed to tap into a small funding grant that allowed us to buy some monitoring equipment and run some experiments with colleagues.

Running an ecological experiment is a three-year process. You put the experiment in the water, and then you go back every three months to assess it. This continues for two years to measure two full cycles of seasonal changes. Then you need to do statistical analysis, write a paper, and get it peer reviewed.

For a very long time before we started to grow as a company, we focused on building the database and doing R&D. As we started to gain more and more projects, we made sure they each had a monitoring program and a control site so we could compare performance between our modified structures and the standard existing seawalls in the area.

But other areas of building the business didn’t come so naturally to us at the start. We never had formal financial education or went to business school. We divided roles between ourselves. Shimrit, my partner, was focused on gaining business development knowledge. I focused more on technical development and on learning about concrete. Because we worked as partners, it was very efficient. Over time, we tapped into people we trust and like to work with, such as family, friends, or professors at our university, to help us grow.

Claire: How is your technology different from normal concrete used for breakwaters and riprap?

Ido: It’s actually very simple. We use the local concrete for building seawalls, breakwaters, and boat slips, but we make it a bit different by adding very small quantities of additional materials to it.

The concrete that is used for marine construction is high-end in terms of structural performance because it’s exposed to salts, abrasion forces by sand, cracking, freezing, and thawing. The chemicals commonly added the concrete mix to achieve this high performance decrease the likelihood that sessile organisms will choose to colonize it.

To test new concrete mixes, we hung what we call “settlement tiles” underwater in different regions. Once we started to gain data, we noticed that some concrete mixes could increase larvae recruitment. However, even though we saw more species in the first few months, there was a die-off later. And why was that? Sessile organisms that have settled on concrete are sensitive in their initial phases to environmental conditions. They can’t escape if turbidity in the water settles sediment on top of them or if turf algae grow over them. In both cases, they’re not going to survive.

To address this, we increased the complexity and the rugosity of the concrete’s surface to create microhabitats, where organisms are protected from sediment and are shaded so algae won’t grow on them. Of course, we did this while staying in compliance with marine construction standards.

Today, we have different levels of offerings. At the first level, we modify the chemistry of the concrete with our admixture. At the second, we apply different agents to modify surfaces to allow species to grow and thrive on the structure. At the third, we incorporate nature-inclusive designs to provide different morphologies and habitats on the structure.

Claire: Has one of the considerations in developing your technology been reducing the CO₂ emissions in the concrete mix?

Ido: Because cement is the main source of emissions in concrete mixes, we’ve always pushed to use concrete mixes with less cement. But at the end of the day, the decision is with the client, and, unfortunately, sometimes low-cement concrete mixes aren’t available locally.

However, by promoting biology with a modified seawall, you can sequester seven times the carbon compared to a standard seawall. This is because oysters, mussels, and barnacles secrete skeletons made of calcium carbonate as they grow, which is one of the most efficient carbon sequestration processes out there. By promoting the biology, we promote carbon sequestration.

But we need to be realistic: Concrete is the second-most-consumed material in the world after water. Because of the size of the market, it will be a long time before supply chains will be able to provide the industry with enough low-carbon construction materials. With the current condition of our seas and ongoing biodiversity crises, we don’t have time to waste, and we need to push the industry toward more nature-responsible marine construction.

Claire: Out of all the projects you’ve worked on, what are some of the standouts?

Ido: One of the most important for the development of our company was the Living Breakwaters in New York, a chain of breakwaters protecting the town of Tottenville at the tip of Staten Island. A hundred or so years ago, this area was the East Coast capital of oyster harvesting. Tottenville was severely damaged during Hurricane Sandy, and one of the reasons was because the oyster beds that used to attenuate the waves are not there anymore.

A large part of the Tottenville breakwaters involves our technology, creating intertidal habitats for oysters to grow and develop. It’s a very important and close-to-heart project, and I’m looking forward to seeing it finalized.

Another beautiful project that recently showed our technology impact had to do with an underwater cable running between two of the Canary Islands in the Atlantic. Our client needed to put this massive cable in an underwater trench and cap it with concrete. They reached out to us, and we developed a system for them.

Only eight months after the project was complete, the client saw that recruitment was very similar to what they see on the natural reef nearby. Now, two years later, you actually need to mark on images where the cable is because it’s hard to see where the natural reef ends and our system starts.

There are also several projects in the United Kingdom that I like. In the southern UK, a certain algae that was not seen there for the past 25 years almost immediately started to grow on concrete that was modified with our technology. It was amazing to see this species on the breakwater and to understand that it’s because of our technology.

Claire: Does it make maintenance hard if you’re essentially creating a coral reef?

Ido: That’s a great question, but the short answer is no. Clients can clean the biology the same way that they clean standard infrastructure for inspection or maintenance. Because we modify the concrete itself, even if they scrape the surface, it’s still going to be chemically balanced and can be recolonized.

Some clients are concerned that once there are more species on the infrastructure, it might restrict maintenance due to regulatory protection of these organisms. This normally works out because regulators across the board, specifically in the US and in some regions in Europe, are more aware of the concept of nature-inclusive design. More companies and entities, NGOs, and regulators are understanding that it is important to build standards for promoting ecology in waterfront designs. These standards then trickle outward and are adopted in other places in the world.

Claire: Looking forward, what plans do you have for ECOncrete?

Ido: We want to promote the notion of responsible marine construction. If you can build in a better way, why not do it? We want to be more available and affordable to our clients, and we also want to help in areas where this concept is less widespread—such as China, India, and Africa—as they start to frame their regulations. We’re pushing ourselves, and we will keep working hard in the coming years with the aim of changing the way coastal and marine infrastructure look and function.

Behind the scenes

This interview is part of LEFF’s Into the Weeds interview series—a series that amplifies individuals whose work contributes to the achievement of the SDGs at every level. We’ll be bringing you insights from renowned experts and the leaders of global organizations and innovative local businesses. Claire Holland (she/her) is an editor at LEFF, and Clair Myatt (she/her) is the manager of LEFF Sustainability Group, for which Katie Parry (she/her) is the director.

Comments and opinions expressed by interviewees are their own and do not represent or reflect the opinions, policies, or positions of LEFF or have its endorsement.