Dune preservation / restoration

Te Paki Sand Dunes and 90 Mile Beach, Aotearoa New Zealand. Photo by Sally Evans.

Coastal regions are frequently chosen for human settlements, yet they are also subject to the relentless forces of erosion, particularly during storms. Despite dune dynamics being integral to the natural ebb and flow of coastal environments, erosion poses significant risks to human life, property, and infrastructure. In response, people often intervene, altering coastlines and dunes to try to safeguard coastal structures like homes and roads  (Magliocca et al., 2011).

However, such modifications can lead to problems when natural barriers, like dunes, are diminished, leaving communities vulnerable to storm surges, tsunamis, and rising sea levels (Ellison, 2018). This vulnerability is further compounded by the effects of climate change. It is important therefore that dunes are preserved and restored where possible, particularly in urban environments where built environments exisits behind the dunes.

Read More

Name of NbS

Dune preservation / restoration

Type of NbS

  • Ecosystem restoration
  • Ecosystem protection

Location

  • Urban
  • Peri-urban
  • Rural

Case study:

Whangamatā dune restoration / construction

Kapukaulua Dune Restoration project

une replanting, Aotearoa New Zealand. Photo from DOC.

Relationship to Indigenous knowledge

In Te Moananui Oceania, dunes play a crucial role in coastal ecosystems and are often intertwined with Indigenous knowledge, practices, and stories. Indigenous communities in Oceania have developed deep understandings of their local environments over generations, including the importance of dunes in coastal resilience.

Traditional knowledge systems often include sustainable practices for dune preservation, such as selective harvesting of coastal vegetation, community-based customary management strategies, and culturally specific approaches to coastal conservation. For many Indigenous peoples in Oceania, dunes serve not only as physical barriers against erosion and storms but also as sacred or culturally significant landscapes. For example the Sigatoka Dunes in Fiji, the Tikopia dune settlements in the Solomon Islands, and the taro pit remnants in the dunes of Ouvea in the Loyalty Isalnds in New Caledonia (Smith, 2014). Some dune plant species are culturally significant to Māori in Aotearoa are used for weaving and tukutuku panels.

Incorporating Indigenous knowledge into coastal management plans can enhance the effectiveness and sustainability of dune preservation efforts. Collaborative approaches that respect and integrate traditional practices can lead to more resilient coastal communities and ecosystems in Oceania, benefiting both indigenous peoples and the broader society.

Read More
Climate change benefits
  • Coastal erosion / wave attenuation
  • Coastal inundation
  • Coastal salt-water intrusion into aquifers
  • Sea level rise 
  • Soil erosion
  • Storm surge

Sand dunes absorb and dissipate wave and wind energy and prevent erosion of the land behind. As wind is deflected over dunes and dune vegetation, sand is trapped, reinforcing the dune structure. Loss of wave energy on dune edges also deposits material to build up the beach and dune edge (Provost et al., 2022). Natural dunes are known to provide a source of groundwater recharge and protect against saltwater intrusion into aquifers (Makowski et al., 2013).

Read More
Societal / socio-cultural benefits
  • Climate change adapatation
  • Disaster risk reduction

Dune ecosystems provide valuable ecosystem services that benefit society, including carbon sequestration, water filtration, and habitat provision for wildlife. The preservation of dunes ensures the continued delivery of these services, which have economic value in terms of climate regulation, water quality improvement, and fisheries support.

Enhancing the adaptability of dunes along the coastal edge as a buffer zone reduces the vulnerability to significant impacts from both natural disasters and gradual erosion. This protection extends to inland areas, safeguarding settlements, housing, and infrastructure.

Read More
Ecological and biodiversity benefits
  • Disturbance prevention (erosion, storm damage, flooding etc.)
  • Fresh water

Dunes provide critical habitat for numerous plant and animal species, including endangered or threatened species. Preserving dunes helps conserve biodiversity, maintain ecosystem balance, and support the overall health of coastal ecosystems. Hesp, (2000) provides the example of 115,000 ha of coastal dunes having been affected by development of agriculture and forestry in Aotearoa New Zealand.

Read More

Technical requirements

Preserving dunes requires a combination of technical measures and management strategies tailored to the specific characteristics of each coastal area. Some key technical requirements for dune preservation follow.Maintaining healthy vegetation cover on dunes is often crucial for stabilisation. This may involve planting native dune-stabilising vegetation species, controlling invasive species that disrupt dune integrity, and implementing erosion control measures such as sand fencing or dune restoration projects. Some projects however remove invasive exotic vegetation in order to enable dunes to return to being more dynamic. An example is the long-term program of marram grass (Ammophila arenaria) eradication in southern Aotearoa New Zealand (Doughboy Bay, Rakiura Stewart Island)  (Konlechner et al., 2015).

Adding sand to eroded beaches / dunes may help replenish dune systems and restore natural coastal processes. Beach nourishment projects may involve dredging sand from offshore sources or redistributing sand from other areas along the coast. See: artificial sand dunes.

In some cases, structural interventions such as seawalls, groins, or breakwaters may be necessary to protect dunes from further erosion and wave action. These measures should be carefully designed to minimise impacts on natural processes and consider long-term sustainability. Nature-based solutions should be considered as alternatives.

Regular monitoring of dune conditions, including vegetation health, erosion rates, and sediment dynamics, is essential for effective preservation efforts. This may involve remote sensing techniques, aerial surveys, field assessments, and community-based monitoring initiatives.

Establishing and enforcing regulatory frameworks, such as zoning ordinances, setback requirements, and coastal management plans, can help protect dunes from inappropriate development and land use practices. Involving the local community is key in dune preservation and restoration.

Read More

Issues and Barriers

Te Moananui Oceania is particularly vulnerable to the impacts of climate change, including sea-level rise, stronger storms, and changing precipitation patterns (Kumar, 2020). These factors exacerbate coastal erosion and threaten dune stability, making preservation efforts more challenging.

Many parts of Te Moananui Oceania are rapidly urbabising (Kiddle, 2021). Rapid population growth and urban development along coastal areas often leads to increased pressure on dune ecosystems. Land reclamation, infrastructure development, and tourism-related activities can degrade dune habitats and compromise their ability to withstand erosion. These are all issues in the region.

Many Pacific Island nations have limited financial resources and technical capacity for coastal management and conservation efforts. This can hinder the implementation of effective dune preservation measures and monitoring programs.

Limited awareness of the importance of dunes and their role in coastal protection can hinder conservation efforts. Engaging local communities in dune preservation initiatives and traditional knowledge exchange is crucial for fostering stewardship and long-term sustainability. 

Inadequate or ineffective coastal management policies and governance structures can undermine dune preservation efforts. Strengthening regulatory frameworks, improving coordination among government agencies, and integrating traditional knowledge into decision-making processes are essential for overcoming these challenges. Land tenure issues, including unclear property rights and competing land uses, can complicate efforts to conserve and manage dune ecosystems. Resolving tenure conflicts and promoting collaborative approaches to land stewardship are necessary for successful dune preservation.

Read More

Opportunities

The natural beauty and biodiversity of dune ecosystems in many places in Te Moananui Oceania offer eco-tourism opportunities that can generate revenue while promoting conservation. Sustainable tourism practices that avoid environmental impacts and contribute to local economies may be a source of incentivising dune preservation efforts.

Financial case

Dunes play a vital role in coastal resilience by buffering against sea-level rise and storm surges. Investing in dune restoration and protection can enhance the resilience of coastal communities to climate change impacts, safeguarding lives, infrastructure, and livelihoods (Ellison, 2018). 

Preserving dunes provides cost-effective natural protection against coastal erosion, storm surges, and flooding. By acting as natural barriers, healthy dune systems reduce the need for expensive engineered solutions such as seawalls or breakwaters, saving on imported material costs, construction, maintenance, and repair costs. The avoidance of disaster-related costs, including emergency response, recovery, and reconstruction, represents a substantial financial incentive for dune preservation.

Exploring innovative financing mechanisms, such as ecosystem service payments, green bonds, and crowdfunding, can provide sustainable funding streams for dune preservation projects. Leveraging private sector investment and philanthropic support can complement public funding and enhance project scalability.

Read More
References
  • Ellison, J. C. (2018). Pacific island beaches: Values, threats and rehabilitation. Beach management tools-concepts, methodologies and case studies, 679-700.
  • Hesp, P. A. (2000). Coastal sand dunes: Form and function (CDVN Technical Bulletin No. 4). Forest Research.
  • Kiddle, G. L., Pedersen Zari, M., Blaschke, P., Chanse, V., & Kiddle, R. (2021). An Oceania urban design agenda linking ecosystem services, nature-based solutions, traditional ecological knowledge and wellbeing. Sustainability, 13(22), 12660.
  • Konlechner, T. M., Ryu, W., Hilton, M. J., & Sherman, D. J. (2015). Evolution of foredune texture following dynamic restoration, Doughboy Bay, Stewart Island, New Zealand. Aeolian research, 19, 203-214.
  • Kumar, L. (Ed.). (2020). Climate change and impacts in the Pacific. Cham, Switzerland: Springer.
  • Magliocca, N. R., McNamara, D. E., & Murray, A. B. (2011). Long-term, large-scale morphodynamic effects of artificial dune construction along a barrier island coastline. Journal of Coastal Research, 276, 918–930. https://doi.org/10.2112/JCOASTRES-D-10-00088.1
  • Makowski, C., Finkl, C. W., & Rusenko, K. (2013). Suitability of recycled glass cullet as artificial dune fill along coastal environments. Journal of Coastal Research, 289, 772–782. https://doi.org/10.2112/12A-00012.1
  • Smith, A. (2014). Cultural landscapes in the Pacific Islands: the 2007 ICOMOS thematic study. Safeguarding Precious Resources for Island Communities World Heritage Paper Series, 38, 52-59.

Further resources