Living Seawalls - How Humans and Nature can Coexist

In my last blog post about Operation Crayweed, we discovered how with time, collaboration, and community, we can create real and substantial change.

What started as a small, community-driven effort to clean up Cabbage Tree Bay transformed not only the bay into the most biodiverse area in Sydney but also led to several similar and interconnected projects all around Sydney Harbour.

One such successful venture with Sydney Institute of Marine Science was the Living Seawalls Project - a plan to regenerate marine species in the harbour by protecting the living seawall habitats.

An essential part of my wellbeing routine is swimming with Sydney’s Cabbage Tree Bay, which was at the heart of the Operation Crayweed project, so I’ve really enjoyed the opportunity to talk to scientists and locals who’ve worked on these projects within Sydney.

And if you’re also interested in how everyday people can collaborate to make our coastal cities a more hospitable home for both humans and nature alike, then I hope these stories inspire you as much as they did me.

Today, I’m joined by Dr Melanie Bishop, who runs the all-female team on the Living Seawalls project. Bishop has over 20 years of experience working within a marine environment. In her earlier career, part of Bishop’s work was documenting the impact humans have on the coastline… which she says ‘got depressing pretty quickly.’

She soon realised her energy was better spent thinking about solutions. Since then, she’s been working on innovations for how humans and nature can coexist within our coastal cities.

What is the Living Seawalls Project?

Built structures are constructed in our oceans for a whole range of purposes; from coping with sea level rises and storm surges, to agriculture and energy production

Unfortunately, although these structures are essential for humans, they typically disrupt natural habitats and come at the cost of biodiversity.

So, what’s the solution?

Well, the concept of the Living Seawalls project is pretty simple. Bishop’s team is incorporating protective habitats within the seawalls, trying to mimic features of nature that support marine life.

The key is to build structures that have the nooks and crannies and protective spaces that marine life flourish in, rather than installing seawalls with flat and featureless surfaces. For example, structures that include the honeycomb weathering of Sydney sandstone, the protruding fingers of sponges, or the complex shapes that muscles and oysters form within the marine environment.

Bishop explains that the team now have 11 different seawall designs, each supporting a distinct ecological community.

The configurations are also customisable so they can be made especially for specific locations and their environmental goals. For example, seawalls can be constructed to include rock pool panels, designed to hold onto water as the tide goes out to support seaweed and crustaceans.

In 2018, the city’s first installation was placed at McMahons Point. In the early days, it was really hard to convince people that this was a meaningful thing to do and wouldn’t cause further damage. However, once that first installation went in there was a real ‘a-ha moment.’ It looked fantastic and was doing exactly what it was meant to do ecologically.

‘Collectively we breathed a huge sigh of relief and thought, ah, we’re on to the right thing here.’

That said, marine habitat restoration, like living seawalls, can’t be used as greenwashing over polluted environments. The seawalls will do well at providing ideal homes for marine life, but it won’t work if the water isn’t cleared up first.

Bishop also points out that we should look to nature-based solutions first, before adding in constructions, such as restoring reefs, and mangroves, and protecting shorelines.

However, these Living Seawalls become a useful tool when those options aren’t available.

How collaboration is key to the future of coastal cities.

While Bishop’s team are doing integral work, they’re not working alone. SIMS (Sydney Institute of Marine Sciences), Macquarie University (where Bishop is based), and the University of New South Wales all work together. Collaboratively their different areas of expertise can help solve a very complex problem.

Together, Project Restore is revitalising marine habitats in Sydney Harbour, bringing together multiple flagship restoration projects operating under the umbrella of the Sydney Institute of Marin Sciences.

Bishop explains that simultaneously restoring multiple complementary habitats is essential. For example, a fish doesn’t rely on a single habitat within its life cycle; they move between several. So collaboratively working on multiple habitats is the key to the greatest change.

Community support is also absolutely key. Without them, it’s hard for marine ecological restoration projects to succeed.

First of all, communities create noise. Councils and developers are much more likely to favour these projects if the community is serving as advocates. Secondly, educating those who live in coastal cities about the value of marine life is important. We need our human populations to care about living happily with nature, Bishop explains.

‘The Manly community is an absolute delight to work with. Their passion and stewardship for the marine environment is second to none.’

Moving forward: A future where humans and nature alike can thrive

Living Seawalls can now be found on three continents, which shows their phenomenal success!

In Sydney, you can see Living Seawalls in action on the side of the pool at Ferry Bower or Fairlight Pool. You can also see some next to the ferry wards at Balmain East and Drummoyne, during low tide at Waterman’s Cove in Barangaroo.

Elsewhere in Australia, installations are going in in the Sunshine Coast, Fremantle, Adelaide, and Newcastle. And internationally in Singapore, the UK, Gibraltar, and beyond.

‘Our vision is that all new construction is co-designed for both humans and nature. We don’t need to be at odds with one another. Although marine construction is the problem, it can also be the solution if we’re designing with ecological principles in mind as well,’ says Bishop.

If you’d like to learn more, head to livingseawalls.com.ie, where you can see what a living seawall looks like, alongside the 11 different panel designs.

Or learn about the water hands-on and just get out there and enjoy our oceans! Like me, Bishop loves getting out in the water; most mornings you’ll find her enjoying the harbour on an outrigger canoe and on Saturdays, her happy place is out on the beach with her daughter.

Experiencing the marine underworld is the best reminder of how much we have to lose.

So grab your reef-safe sunscreen before taking a dip, take part in community clean-ups, or read up on local initiatives in your area if you want to keep our Earth beautiful for the next generation of humans and animals.