Living seawalls / biodiversity tiles

Living Seawalls. Photo from Reef Design Lab.

Living seawalls or biodiversity tiles are used on artificial structures like sea walls in marine environments. The added texture adds a surface for sea biota to cling to or create new habitats. Living seawalls are an enhancement strategy for existing structural coastal protection (Jackson et al., 2022). See also: Living breakwaters.

Name of NbS

 Living seawalls / biodiversity tiles

Type of NbS

Engineered interventions (not using vegetation) 

Location

Added to seawalls or constructed rock breakwaters

Case Study

Kete Tiles

Volvo Living Sea Walls

Newly installed Living Seawall. Photo by Reef Design Lab

Relationship to Indigenous knowledge

Living seawalls and biodiversity tiles do not come directly from traditional ecological knowledge. However, for indigenous communities in Te Moananui Oceania, the ocean is not just a resource but a fundamental aspect of cultural identity and livelihood (Mihaere et al., 2024). Traditional ecological knowledge passed down through generations provides insights into the intricate dynamics of coastal ecosystems, including the behaviour of marine species, seasonal patterns, and sustainable harvesting practices. It is crucial to include Indigenous people therefore in the design of such systems.

Climate change benefits
  • Changes in phenology 
  • Coastal erosion
  • Coastal inundation and storm surge
  • Ocean acidification
  • Sea level rise 
  • Temperature rise

Using habitat tiles on sea walls gives these structural systems ecological benefits that increase climate change resilience, giving habitat to oysters, barnacles, sponges and other organisms including fish. These habitats provide ecosystem services including but not limited to chloride penetration, enhanced resistance to erosion, sourcing, and abrasion, reduced maintenance, and prolonged lifespan (Perkol-Finkel et al. 2018). Benefits other than biodiversity enhancement, include maintenance of clean water, fisheries production, and carbon sequestration (Vozzo et al., 2021). Further research is underway to try to understand the potential benefits of water filtration and carbon sequestration by using living seawalls and biodiversity tiles.

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Societal / socio-cultural benefits
  • Disaster risk reduction and resilience

shoreline environments. Increased biodiversity tends to enhance the climate adaptation potential of ecosystems which humans live in.

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Ecological and biodiversity benefits
  • Biodiversity health and conservation
  • Biological control (regulation of pests and disease)
  • Disturbance prevention (erosion, storm damage, flooding etc.)
  • Genetic resources (diversity)
  • Habitat provision
  • Purification (of water, soil, air)

Habitat biodiversity is the key benefit of living sea walls and biodiversity tiles. The development of designed concrete tiles on sea walls has re-introduced habitat complexity. The complexity of habitat means a greater density of spatial elements and therefore supports a richer and larger number of diverse species (Strain et al. 2021). The enhancement of sea walls allows for ecosystem services including food, shelter, and nursing grounds for a diverse range of invertebrates, algae, and fish (Perkol-Finkel et al. 2018). With this increased biodiversity, results of study sites have seen that a build-up of oysters, barnacles, sponges, and other organisms have deposited calcium carbonate skeletons that form habitats (Perkol-Finkel, S et al 2018).

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Technical requirements

The panels are first designed digitally and are informed by forms and features seen in natural rocky shores or mangrove roots. These are fastened onto sea walls where they become covered naturally in marine life over time.

Issues and Barriers

Evidence-based research is still evolving. This limits the knowledge of the benefits created and perhaps limits people’s confidence in using the tiles.

Opportunities

Living seawalls and biodiversity tiles offer opportunities for rehabilitating degraded habitats and enhancing marine biodiversity, thereby bolstering ecosystem resilience in the face of climate change impacts.

In Te Moananui Oceania, where indigenous knowledge and cultural connections to the ocean are deeply ingrained, involving local communities in coastal conservation efforts is essential. By incorporating traditional ecological knowledge and practices into project design and implementation, living seawalls and biodiversity tiles can foster a sense of ownership and stewardship over coastal resources, empowering communities to take an active role in environmental management.

The development of these nature-based solutions catalyses opportunities for collaborative research and innovation. Te Moananui Oceania boasts rich marine biodiversity and Indigenous knowledge systems, providing fertile ground for interdisciplinary research.

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Financial case

Coastal habitats in Te Moananui Oceania, such as coral reefs, seagrass beds, and mangroves, are vital for supporting marine biodiversity and fisheries productivity. However, these habitats are increasingly degraded due to human activities and climate change impacts. Living seawalls and biodiversity tiles may offer opportunities for restoring and enhancing these habitats by providing shelter for shell fish, juvenile fish, and other associated biodiversity. By bolstering fisheries productivity and ecosystem health, these initiatives may generate economic benefits for local communities, such as increased fishery yields, improved food security, and enhanced ecotourism opportunities.

Living Seawalls. Image by Alex Goad / Reef Design Lab.
References
  • Simcock, R. (2017). Water sensitive Design in Auckland, New Zealand. In Susanne M. Charlesworth, Colin A. Booth (Eds.). Sustainable surface water management: A handbook for SuDS (380 – 392). https://doi.org/10.1002/9781118897690.ch28
  • Filazzola, A. (2019). The contribution of constructed green infrastructure to urban biodiversity: A synthesis and meta-analysis. Journal of Applied Ecology, 56 (9), 2131 – 2143.  https://doi.org/10.1111/1365-2664.13475
  • Mazer, G. (2001). Limitations to vegetation establishment and growth in biofiltration swales. Ecological engineering, 17 (4), 429 – 443). https://doi.org/10.1016/S0925-8574(00)00173-7
  • Chikeluba, I.J. (2022) Urban green infrastructure and its effects on climate change – a review. Available at SSRN 4190459. http://dx.doi.org/10.2139/ssrn.4190459
  • Newman, G.D & Qiao, Z. (2022) Landscape Architecture for Sea Level Rise: Innovative Global Solutions. Routledge. doi: 10.4324/9781003183419
  • Kabisch, N., Korn, H., Stadler, J., & Bonn, A. (2017). Nature-based solutions to climate change adaptation in urban areas: Linkages between science, policy and practice. Springer Nature.
  • Groves, W. W., & Hammer, P. E. (1999). Analysis of bioswale efficiency for treating surface runoff (Doctoral dissertation), University of California, Santa Barbara.