Part 4: You will hear a lecture about dune shield restoration, including methods used and a project outcome.
LECTURER: Today I want to talk about dune shield restoration and why it matters for coastal protection. When we think about sea defences we often picture walls and rock barriers. Those can be useful, but nature based solutions can work alongside them and sometimes reduce the need for heavy engineering. Sand dunes are one of the best examples.
Dunes matter because they form a natural barrier against waves. A healthy dune ridge sits between the beach and the land behind it. When storm waves arrive, the dune absorbs energy and sand can shift without damaging buildings. In that way dunes protect roads and homes inland. Dunes also reduce coastal erosion. By holding sand in place and slowing the wind, they limit how quickly the shoreline is worn away. If dunes are lost, storms reach further inland and the coast becomes more vulnerable.
Dunes are also easy to damage, especially in popular visitor areas. One main cause is trampling. When people walk over the same path again and again, sand becomes loose, vegetation is crushed, and plants die back. Without roots, wind can lift and carry sand away. Another cause is off road vehicles. Even a single vehicle can leave deep tracks that cut through the dune surface and break the protective layer of plants and compacted sand.
Once the surface is damaged, strong winds enlarge the weak spots. Small openings can grow into bigger holes known as blowouts. A blowout can expand quickly because wind speeds up as it funnels through the gap. As sand is removed, the dune ridge lowers and the barrier effect is reduced. If a dune system develops several blowouts, it becomes harder for plants to return without support.
So how do we restore dunes and rebuild the shield. A common method is to install low wooden fences. These are placed in lines across damaged areas. The fences slow the wind near the ground and trap moving sand. Over time, sand accumulates and the surface begins to rebuild. The fences also guide visitors away from sensitive spots and reduce accidental trampling.
The second method is planting marram grass. Marram is suited to dunes because it tolerates salty air and shifting sand. It has long roots that bind sand together. Restoration teams plant it in clumps or rows, often after fencing has started to collect sand. As the grass grows, it stabilises the surface and reduces the chance that new blowouts will open.
The third method is managing visitor pressure. Many dunes are damaged not only by storms but by daily use. Raised boardwalks help by giving people a clear route to the beach without walking directly on the dunes. Boardwalks protect plants, reduce trampling, and keep access safer in wet weather. Signs and barriers at informal paths reinforce the message and make the preferred route obvious.
Let me give you an example from North Bay. The site had suffered for years from trampling, especially in summer, and from vehicles entering at the edge of the beach. Several blowouts had formed and the dune ridge was patchy. The restoration project combined all three methods. First, access points were controlled. The team closed some unofficial paths and directed visitors to a main entry route. Next, they installed low wooden fences across the most damaged sections. Finally, they planted marram grass in patches along fence lines to anchor new sand.
The outcome was encouraging. After access was controlled, vegetation cover increased within one season. The new plants reduced wind erosion and helped the dune surface hold together. At the same time, far fewer blowouts formed because the most vulnerable spots were protected and visitor movement was guided. Local volunteers helped with monitoring, reporting broken fencing and reminding visitors to stay on the boardwalks. Education sessions encouraged visitors to cooperate daily.
There are limits. Fences can be damaged by storms, and boardwalks need maintenance. Planting must be timed well so young grass is not washed away or dried out. But the wider lesson is that dune restoration works best when it is treated as a partnership between engineers, ecologists, and the community. It also works best when it is continuous, with small repairs made quickly before new gaps grow.
To conclude, dune shield restoration is a practical way to strengthen a coast while supporting wildlife habitat. Long term success depends on public behaviour. If people follow marked paths, avoid trampling fragile areas, and keep vehicles off protected zones, dunes can recover and continue to act as a barrier and reduce erosion. If those behaviours do not change, damage returns and costs rise.
