So much of life on our blue planet relies on the health of its oceans and coastlines. In recent years, we’ve seen how a worldwide decline in reef ecosystems can lead to significant erosion, acidification, and losses in marine species. It’s a problem that’s even affecting the resilience of some cities, many of which are struggling to maintain their harbours and waterways. Taking on this problem in New York City is industrial designer Mary Lempres, who won the Redesign Everything Challenge with her project, Reef Rocket.
Reef Rockets are bio-cement structures that mimic natural oyster reefs to protect shorelines, filter seawater, and boost biodiversity. Grown using plant-based enzymes and crushed waste like shells and glass, this material solution is free of fossil fuels and ideal for growing coral and oyster reefs. It offers a cleaner, cheaper, and more durable alternative to industrial cement, fostering a bio-circular economy and supporting reef restoration efforts all over the world.
We caught up with Mary during the Redesign Everything Sprint to learn more about tapping into nature’s genius, the role of citizen science in climate action, and the challenge of building a sustainable business.
Mary Lempres at the Redesign Everything Sprint. Photo: Anisa Xhomaqi. Right: A Reef Rocket structure. Photo: Reef Cycle.
Hi Mary, can you introduce yourself and your project?
Yes! So, I’m a biodesigner. I’ve always been interested in both science and art and wanted to find a way to exist in between the two different disciplines.
I live in Brooklyn, New York, where there aren’t many ways to access nature. You have to get in a car and drive for a couple hours to get to the closest place that we associate with it. However, I think many people don’t realise that we actually have nature all around us — in our waterways — and they’re largely forgotten or seen as an obstacle to cross to get from point A to point B. So, a major inspiration and starting point for this project was trying to find a better way to connect with nature.
“New York Harbour used to have one of the largest and most biodiverse reef systems in the world.”
Why do you think this is so important?
So, New York Harbour used to have one of the largest and most biodiverse reef systems in the world, and because of that, we had dolphins, we had seahorses. We had a lot of animals and marine species that we don’t see anymore. And that’s because of our activities as settlers in America and the way that we’ve treated our city and the way that we’ve built our infrastructure, which is largely outdated.
So it’s these actions that have contributed to the loss of our local reefs. Especially with climate change, we’re now seeing the impacts and effects that the loss of nature’s infrastructure and ecological services are having. And so reef restoration has emerged as a really important solution to combat climate change, both looking at sea level rise and increased coastal hazards like hurricanes.
Take for example, Hurricane Sandy. The reason that it impacted the community of Brooklyn so severely was because of the wave energy that was created from the hurricane. We didn’t have a way to dampen that energy through ecological means. So instead, we suffered very extreme impacts from wave energy and flooding. This could’ve been prevented with natural reefs, especially to the degree that we used to have reefs in the harbour. So, that’s a major driver of why we’re investing in reef restoration, both through citizen science and volunteer activities, as well as these different nonprofits that are bringing scientists to our harbour to actively restore reefs.
Reef Rockets are made from biocement, rather than metal or plastic. Photo: Reef Cycle.
Can you tell us about the reef structures you’re developing?
So currently, we have a few different structures we’re testing, because the best way to restore reefs is to put structures in the water. We are also putting oyster larvae in the water, but they can’t do anything without having physical structures to attach to and grow on.
So first we tested with mesh bags filled with shells. The benefit of this is that shells are calcium-carbonate based, and that material is highly biocompatible. It’s the ideal building block for oyster reefs. So we’ve tried putting shells from different restaurants into bags and putting that into the water, as well as gabions, which are huge metal structures that we fill with waste shells. But those have various issues associated with their being so porous. They get covered in sediment and get buried. And they also are metal and plastic, which both degrade to harm our environment.
“All these current solutions are made using industrial material, which is not something that occurs in nature and not something that nature knows how to handle. This means they’re all polluters.”
We also tested structures made out of cement, which has been the most successful so far. However, cement is a major carbon emitter. For every tonne of cement you use, you produce an equivalent amount of CO2. So all these current solutions are made using industrial material, which is not something that occurs in nature and not something that nature knows how to handle. This means they’re all polluters. So that’s how we got into this challenge.
So how are you addressing this problem?
We’re actually growing cement. The standard concrete cement is Portland cement, which is produced by mining for different minerals, and then putting it through a kiln, which heats it to really extreme temperatures, and that’s where a lot of the fossil fuel consumption occurs. For our cement, you don’t have to put any energy into the production process, because we’re using plants to grow it. So what we do is we extract an enzyme from plants and combine it with waste aggregate made from glass and crushed shells,in order to grow a kind of bio-cement. That’s the core of our technology and the process that we’re scaling.
Mary Lempres and Reef Cycle team member Helio Takai at the Redesign Everything Sprint. Photo: Anisa Xhomaqi.
Can use this material for construction as well as reef restoration?
Yes, you can. It’s an emerging technology, which has a lot of potential areas of application, and that was something that was very important to us. We applied it to reef restoration first because it was something our community was already working on, but also because we realised that the growth process we’re working with is identical to how oysters and coral forms their reefs. So our structures are literally mimicking nature, and because of that, they actually outperform structures made from industrial cement in some really critical areas, like marine biocompatibility.
In one of our recent tests, we found a baby oyster that actually grew on our material. Usually you’d have to physically put larvae onto artificial material to get them to attach, whereas this happened naturally on a very tiny sample. The odds of this are very small. We have a couple now that have attached to our material in this way, and we’re all amazed — all the scientists we work with are giddy, they can’t believe it. We really proved that by using nature, we can actually keep nature’s functionality — something which has been developed over millions of years. So, this was incredible proof for us that really validated this path that we’re on.
“The scientists we work with are giddy, they can’t believe it. We really proved that by using nature, we can actually keep nature’s functionality.”
What is the next goal you’re currently working towards?
We are building a pilot programme with our non-profit and community partners and looking at how we can actually create a closed-boundary production system. We already have a shell collection programme with restaurants. Oysters are really important to our cuisine in New York City, they have major cultural significance so we have lots of oyster shell waste that are coming from restaurants, and we have a collection programme with our partners to collect those and repurpose them.
Then we’re looking at growing the plants that produce these enzymes on Governors Island, that’s projected to be underwater in the next five to ten years. And so it’s really critical that we do this work as soon as possible and get as many structures into the water as we can.
We’re treating that as our boundary to prove that we can do this locally and to fabricate and produce seawalls. We want to have seawalls that will align the Brooklyn waterfront as a way to engage people in what we’re doing and prove that this works at a larger scale.
Reef Rockets are ideal for supporting the growth of oysters and coral. Photo: Reef Cycle.
What kind of responses do you get from people who come across the project?
Most people in New York City don’t even know that there were oysters here, and that they’re gone, or that we’re working to restore them. I think within our community of volunteers, Reef Rockets offer an image of hope.
Our structures are small and modular, and that’s all by design, because this way you can install them without a permit. You can do this off any harbour, along any coastline, and it allows everyday people to actually engage in the process. If you go larger, then you need cranes to install it. One day we’ll get to that scale, as it’s still a goal of ours to continue to build this for different applications. But for our current context, rapid deployment was essential.
“Reef Rockets are small and modular, and that’s all by design. You can install them off any harbour, along any coastline.”
Lastly, what is the message that you hope people will take away from this project?
I think what’s most important to us is investing in nature and showing that nature has all these solutions that’s already been developed for us. It’s teaching people to reconnect and to acknowledge what already exists around us, and that these solutions can help us address the crisis we’re in. Because oyster restoration is a global problem. We need to restore them, because if we don’t have oysters, other species can’t survive. They are an ecosystem builder, they filter 50 gallons of water a day. They have all these incredible benefits that marine biodiversity needs to survive.
So we are excited about what reef restoration can mean for climate resiliency. Now it’s just figuring out how to fit into that, how to build a business around that, and how to get people to invest in it through education.
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This interview has been lightly edited for clarity and length.
Words by Dune Daffin, interview by Natasha Berting and Chieri Higa.
Designing the Reef Rocket structure. Photo: Reef Cycle.