Living shorelines

Before And After: Living shoreline by Lewes, Delaware’s Little League ball fields, located on the Lewes-Rehoboth Canal, USA. Photos by Partnership for the Delaware Estuary, CC BY-NC-ND 2.0 DEED.

Living shorelines provide a protective barrier on the edge of a body of water the same way concrete seawalls do. Living shorelines protect land against sea and wave activity while also providing habitat and shelter for wildlife between land and water. Te Moananaui Oceania has a large number of shorelines that can use this nature-based solution.

submerged in water or out of it, which creates a barrier between land and water. This may be combined with areas of rock or concrete to support plant growth. This barrier is not only more versatile but is also more sustainable and visually appealing because it uses natural materials and living organisms as opposed to slabs of concrete and man-made materials. The barrier it provides is also softer, less harsh on the eye and creates less disconnect between the land, people and the water erosion it is mitigating. Erosion may be caused by large swells, and rising water levels. Living shorelines can also absorb displaced sediment from storms and large swells. See also: coastal setbacks.

Name of NbS

 Living shorelines

Type of NbS

Hybrid living/engineered interventions

Location

The water’s edge, especially where seawalls would be or have already been placed.

Scott’s point (before implementing living shoreline NbS). Photo from: NSW Department of Primary Industries (Jenkins and Russell, 2017).

Relationship to Indigenous knowledge

Living shorelines in Te Moananui Oceania are deeply rooted in Indigenous knowledge frameworks that prioritise sustainability, resilience, and the interconnectedness of humans and the environment. This includes traditional methods of coastal protection using natural materials like coral, rocks, and plants, as well as community-based governance systems that emphasise collective responsibility for coastal resources.

Climate change benefits
  • Biomass cover loss
  • Coastal erosion
  • Soil erosion

Living shorelines are designed to address several climate change impacts on coastal areas, primarily focusing on sea-level rise, increased storm intensity, coastal erosion, and habitat loss. 

Living shorelines help mitigate the effects of sea level rise by providing natural buffers. Coastal vegetation such as mangroves, marsh grasses, and other native plants absorb wave energy and reduce the impact of high tides and storm surges. This helps to maintain shoreline integrity and reduce the risk of flooding in coastal communities (Currin, 2019). As climate change leads to more frequent and severe storms, living shorelines can play a crucial role in protecting coastal areas. The vegetation and natural features of living shorelines act as barriers, breaking up wave energy and reducing the force of storms on the coastline. This helps prevent erosion and damage to coastal infrastructure. Living shorelines are also effective in combating coastal erosion, which is exacerbated by sea-level rise and storm events. The roots of coastal plants stabilise sediments, preventing them from being washed away by waves and currents. Over time, this process builds up sediment and helps to rebuild eroded shorelines.

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Societal / socio-cultural benefits
  • Climate change adaptation
  • Disaster risk reduction
  • Water security and quality

Living shorelines enhance the resilience of coastal communities by reducing their vulnerability to climate change impacts such as sea-level rise, storm surges, and coastal erosion (Currin, 2019). Coastal infrastructure, including homes, businesses, and public facilities, is often at risk from erosion and flooding. Living shorelines preserve coastal property and reduce the need for costly infrastructure repairs and replacements.

Vulnerable communities, including those with limited resources or marginalised populations, are disproportionately affected by climate change impacts on coastlines. Living shorelines promote social equity by prioritising nature-based solutions that benefit all community members, including low-income residents, Indigenous peoples, and other vulnerable groups.

Many coastal communities have strong cultural ties to their coastal environments, including traditional practices, livelihoods, and cultural heritage sites. Living shorelines help preserve these cultural assets by maintaining coastal landscapes, habitats, and natural resources that are integral to local cultures and identities. Moreover, implementing living shorelines often involves community participation and engagement. It also provides opportunities for education, skill-building, and empowerment within coastal communities.

Coastal economies often rely on tourism, fishing, and other marine-linked sectors. As Arkema et al. (2017) note, living shorelines play a crucial role in maintaining economic stability by safeguarding coastal ecosystems and fisheries. These vibrant habitats draw in tourists, offer recreational activities, and sustain the livelihoods of those reliant on marine resources. Living shorelines create avenues for fishing, birdwatching, kayaking, and nature tourism, enhancing recreational opportunities, and enriching cultural and educational experiences.

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Ecological and biodiversity benefits
  • Climate regulation
  • Disturbance prevention
  • Purification
  • Soil building
  • Habitat provision
  • Species maintenance
  • Recreation and tourism.

Coastal ecosystems in living shorelines contribute to climate regulation by influencing microclimate conditions, moderating temperatures, and reducing heat island effects in coastal areas (Currin, 2019). Mangroves, salt marshes, and seagrasses are particularly effective at sequestering carbon, helping to mitigate climate change by reducing greenhouse gas concentrations (Davis et al., 2015).

Climate change can lead to habitat loss for coastal species due to erosion and sea-level rise. Living shorelines create and enhance habitats for various marine and terrestrial species (Bilkovic et al., 2016). 

Coastal vegetation in living shorelines helps improve water quality by filtering pollutants, sediment, and nutrients from runoff and coastal waters. Roots and vegetation capture sediment, trap pollutants, and absorb nutrients, reducing nutrient loading and improving water clarity. This benefits aquatic habitats and supports marine life.

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Technical requirements

The first step to implementing a living shoreline is to analyse the chosen area and determine whether the land needs further stabilising to accommodate the plants and organic materials that are necessary. If the land is not stable enough due to erosion it will need to be developed further before putting the living shoreline in place (Miller et al., 2015).

Existing sea walls and natural/man-made debris may need to be removed. Sewage and stormwater issues may need tobe addressed. 

Once prepared, the installation can begin, which includes placing organic fibre mats, planting a range of aquatic plants and sometimes fabricating oyster reefs. Maintenance includes planting new vegetation and adding additional sand/soil as well as monitoring new habitats.

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Issues and Barriers

Plants take time to grow and become fully established. Introducing or promoting certain plant species or structures in living shoreline projects can pose risks, such as the introduction of invasive species or altering natural ecosystems. Coastal protection measures, including living shorelines, require financial support for research, planning, construction, and long-term maintenance. Miller at al., (2022) provide Living Shorelines Engineering Guidelines.

Opportunities

There are many opportunities for living shorelines in Te Moananui Oceania because of the large number of shorelines around islands. Restoring and enhancing these ecosystems can provide natural coastal protection, support biodiversity, and enhance ecosystem services such as carbon sequestration, water filtration, and habitat provision (Arkema et al., 2017).

Financial case

The cost-benefit analysis of living shorelines can vary widely depending on factors such as project scope, location, design complexity, materials used, labour costs, and environmental conditions. Cost-benefit ratios for living shorelines can vary depending on project-specific factors, but studies have shown that the benefits, including avoided damages by not managing coastlines, increasing ecosystem services, and property value enhancement, often outweigh the initial and ongoing costs.

References
  • Arkema, K.K., Scyphers, S.B., & Shepard, C. (2017). Living shorelines for people and nature. In Living shorelines (pp. 11-30). CRC Press.
  • Bilkovic, D.M., Mitchell, M., Mason, P., & Duhring, K. (2016). The role of living shorelines as estuarine habitat conservation strategies. Coastal Management44(3), 161-174.
  • Currin, C.A., Chappell, W.S., & Deaton, A. (2010). Developing alternative shoreline armoring strategies: the living shoreline approach in North Carolina. Puget Sound shorelines and the impacts of armoring. Proceedings of a state of the science workshop. U.S. Geological Survey. http://hdl.handle.net/1834/30714.
  • Currin, C.A. (2019). Living shorelines for coastal resilience. In Perillo, G.M.E et al., (eds), Coastal Wetlands: An Integrated Ecosystem Approach (pp. 1023-1053). Elsevier. https://doi.org/10.1016/B978-0-444-63893-9.00030-7 
  • Davis, J.L., Currin, C.A., O’Brien, C., Raffenburg, C., & Davis, A. (2015). Living shorelines: coastal resilience with a blue carbon benefit. PloS one10(11), e0142595.
  • Miller, J.K., Kerr, L., Bredes, A. (2022). Living shorelines engineering guidelines: 2022 update. New Jersey: Stevens Institute of Technology.