Australia’s iconic Sydney Harbour is a world-famous destination for millions of local and overseas visitors. On the surface, the harbour looks enticing, but under water it’s been a different story for the resident marine life. Since the 1800s, human interventions such as the construction of sandstone seawalls, built to protect the coast and reclaim land, and other structures such as pilings, built to support travel, tourism, and commerce activities in the city, have affected more than half of the shoreline. These changes have destroyed many of the harbour’s natural habitats and led to progressive declines in water quality and marine biodiversity.
In response to the problem, which is common to marine environments around the world, marine ecologists Dr. Mariana Mayer Pinto, from the University of New South Wales, and Associate Professor Melanie Bishop and Dr Katherine Dafforn, from Macquarie University, have led a team that has developed a technology-based solution to recreate shelter and breeding sites for the growth of seaweed, fish, and invertebrate species – an environment in which marine life can once again flourish. A simple idea, Dr. Mayer Pinto says, that works. But, she adds, it’s based on 20 years of research carried out globally, including at the Sydney Institute of Marine Sciences (SIMS).
In 2015, Mayer Pinto, Bishop and Dafforn began collaborating with industrial designer Alex Goad, director of Reef Design Lab in Melbourne, to produce 3D-printed customised concrete panels that mimic a variety of natural marine micro-habitats. The first step is designing a panel based on ecological data about the site supplied by the research team. Then, a reusable mould is 3D-printed and concrete panels are cast from it. Panels, each weighing approximately 23 – 30 kilograms, are attached to either a flat seawall or substrate in a lattice-like framework. They can be installed bare or with living oysters and sea weeds attached.
Receiving approval for larger installations of panels took time due to the logistics involved and the permits required. “Each council can interpret the works a different way,” Mayer Pinto explains. It was North Sydney Council that stepped in and helped make it happen. “We call them our champions,” says Mayer Pinto. “They were the first ones that said: ‘Yeah let’s do it!’”
The Council’s support triggered other philanthropical, government and corporate sponsorships, and in 2018 the Living Seawalls project was officially established with the installation of panels at two sites in Sydney Harbour. The first ‘living seawall’, located in Milson’s Point under the Sydney Harbour Bridge, was sponsored by North Sydney Council and Volvo. It ingeniously imitates mangrove roots, creating habitat for filter feeders like mussels, and other marine fish species. The second site, at Sawmiller’s Reserve, features a range of panel designs that recreate crevices and ridges, rockpools, “swimthroughs”, and pitted surfaces, as well as flat panels that serve as a control in ongoing research into biodiversity at these sites. The panels are designed to last 20 years in situ.
To date, the largest ‘living seawall’ is located at Waterman’s Cove at Barangaroo. It’s the only installation where panels are completely submerged, and a community of oysters, sponge fingers and other species is flourishing there. The installation was sponsored by Lendlease, a long-time collaborator, in November 2020, while funding from Infrastructure New South Wales (INSW) supports the monitoring of the panels through methods such as on-site video recordings and photography, and sampling and identification of marine species.
Today, eight installations in and around Sydney Harbour are reducing the massive footprint that human constructions have made in the mangrove forests, and oyster and seagrass beds, says Mayer-Pinto. Her team have documented increases of up to 36% in the number of fish, seaweeds and invertebrates at these sites. At Sawmiller’s Reserve, the researchers observed six species of algae and invertebrates on the living seawall that were not found on either unmodified walls or natural rocky shores in the area. Water clarity and quality has also improved due to growing populations of oysters and mussels filtering particles from the water, benefitting those who enjoy recreational activities in the area, such as water sports, fishing and swimming.
No surprise, then, that the project has expanded to Port Adelaide, South Australia (2019) and Townsville, Queensland in partnership with James Cook University (2021 as well as overseas. There are installations in the Port of Gibraltar in Europe (2019); Keppel Bay Marina, Singapore (2020) in partnership with the National University of Singapore; and Milford Haven in Wales (2020). Mayer-Pinto says the blueprint for the Living Seawall panels and the installation techniques can be adapted to suit the substrate and biological profile of temperate or tropical locations.
The extraordinary potential of the Living Seawalls innovation on a global scale was recognised when the project was selected as one of three finalists in the Revive our Oceans category in the 2021 Earthshot Prize, a highly prestigious global environmental prize.
From a design perspective, the unique fusion of form and function in the panels has been recognised in exhibitions around the world including the 2022 Biennale of Sydney, the Smithsonian Design Museum in New York and the Helsinki Design Museum.
Immersing the public in the science
“In the marine environment, everything is out of sight, out of mind,” says Mayer Pinto. “We are very passionate about communicating the science and the importance of the marine environment in the world.” The team’s different personalities and style of communicating information complement one another, she says. “We tend to joke that I am the passionate one. Katie’s very eloquent, and Mel is the one who will give you all the facts. We make a good team I think.”
The data the team collects is invested into educating local and international communities about the social, economic, and environmental benefits the living seawalls represent. Support from SIMS and funding from partner associations has facilitated a range of public outreach activities, including seminars at community venues and immersive experiences in ocean pools, where the team can demonstrate how effective the installations are in rewilding the environment and supporting marine biodiversity, says Mayer Pinto.
“We participate in the Ocean Lovers Festival at Bondi Beach,” says Mayer Pinto. “Every year we have panels that are placed in the swimming pool at Icebergs, alongside Operation Crayweed [a research project that aims to restore Sydney’s underwater forests]. Adults and children can swim among the algae and the habitat panels. That’s a very good way of raising awareness.”
Engaging and inspiring young minds to explore the ocean and learn about sea creatures is an important part of the project’s outreach. The team creates activities for educational events held at the Maritime Museum and libraries across Sydney during Science Week, providing kids with the opportunity to learn about the marine ecosystems the living seawalls support by designing their own panels.
Maintaining public interest in the project has never been difficult. Living Seawalls is a good news story, Mayer Pinto says, that inspires anyone feeling overwhelmed by the problems associated with climate change and pandemics. “People really appreciate a good story that gives you hope,” she says.
Mayer Pinto says anyone can emulate the Living Seawalls story if they take it step by step. “You don’t need to be an Einstein to do it,” she says. The possibilities for developing an effective science-based project like Living Seawalls are endless because technology can offer innovative solutions to problems experienced by human society and the natural environment. Mayer Pinto’s advice to others is: “Be brave, try it and be passionate … it doesn’t feel like a burden when it’s something you like doing.”
Article by Gabrielle Ahern