Sustainable Beaches and Dunes
The beach is a favorite gathering place for many islanders. Although it provides a tranquil, stress-relieving and beautiful place to be, it also performs many other natural services.
- It provides wildlife habitat for our native species, many of which are found only in dune fields, including dwarf live oak, prickly pear cactus, sea oats, six-lined racerunner lizards and Spanish bayonet.
- Beaches and dunes provide important wildlife corridors that can get animals from one end of the island to the other without crossing roadways.
- Dense dune vegetation can protect your house and landscape from damaging salt spray. Dunes provide important storm barriers that protect upland property from the effects of wave energy, and can store storm water in the troughs between the dune peaks to minimize flooding. Our beaches also are a major draw for tourists year round. For all these reasons, we need to protect our beach-dune system and encourage the formation of new dunes.
In nature, new dunes form when wind-blown or water-transported sand starts to pile up. Many times, wind-blown sand hits and is caught by the brown stems of Spartina grass that wash up on the beach from the marsh to form what we call wrack. This wrack not only forms a good base for the building of a dune, but as it breaks down, provides nutrients for plants that take root in the emerging dune and help anchor it. We help this natural dune building process by putting out sand fencing, either in "V" shapes or parallel lines, to catch wind-blown sand. In some cases, we also plant native, salt-tolerant plants on these new dunes to help anchor them; in others, "volunteer" plants from nearby dunes take hold.
In 2009, the Town took a giant step in protecting our dune systems by passing the Critical Storm Protection and Dune Accretion and Transition Area Ordinance. This ordinance creates a line adjacent to the beach that prohibits most development in the dune systems. For more information, check out the Land Management Ordinance on this website.
If you live adjacent to the beach, you can help protect our beaches and dunes by taking the following actions:
- Don't walk or take a bicycle or other wheeled vehicle through the dunes. Most dune plants have roots that are very close to the surface of the sand, and are easily damaged or killed by compaction. Once the plants are gone, the sand begins to erode away. Only use existing paths or dune walkovers to access the beach. If you are planning to build a dune walkover, contact the Town first, as there are local and state guidelines that must be followed so that the dunes are not damaged. Construction in the dunes is limited to dune walkovers.
- Never remove dune vegetation, or plant non-native or invasive plants in the dune system. Our native dune plants are protected by law. If you want to prune them to maintain a view of the ocean, or you want to reestablish native vegetation on them, contact Town staff, who will be glad to assist in both. Some non-native plants, such as beach vitex, can actually destroy all native vegetation and cause dune erosion.
- Don't store anything in the dunes. The action of dragging boats, chairs and other furniture in and out of the dunes kills plants and causes erosion of the dune.
- Never place carpet or other materials in the dune field. This cuts off oxygen to plant roots and can cause leaching of dangerous chemicals (such as stain preventers, formaldehyde, etc.) in the carpets into the groundwater.
- Dune vegetation doesn't need to be fertilized; the plants that grow in dunes are adapted to the nutrient-poor conditions found in very sandy soils. Fertilizer, herbicide or other chemicals used in the dunes will move through the porous sands very quickly and contaminate the groundwater.
You may notice that some of the woody plants in the dunes look "burned" one to two weeks after a few windy days on the beach. This is caused by wind-blown salt spray from the ocean, which kills leaves and sometimes buds on these plants. In major storms, some of this vegetation will be killed from salt spray, but for more normal conditions, these plants will regrow new leaves and buds. You can see the result of salt spray "pruning" on live oaks near the ocean. Look at them from the side, and you will notice that the part of the canopy nearest the ocean is lower than the part furthest from the ocean, so the canopy appears to "slope" away from the ocean.