Open coast beaches are exposed to constant wave action and sand is constantly moving within the dynamic beach and dune system. Open coast animals are especially adapted to live in these conditions.
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Our region’s beaches
The West Coast of the Region is characterised by long open sand beaches often backed by wind-blown dunes. On the East Coast, beaches are generally shorter, interspersed between rocky headlands.
Most of the Region’s open coast beaches are sandy (for example, the long iron-sand beaches of the West Coast). Fine sand beaches are found on more sheltered stretches of the coast, such as in bays and sheltered inlets. Some beaches are made up of gravel, pebbles, cobbles or boulders. Open coast beaches are exposed to constant wave action.
The mobile beach
Sand constantly moves within the dynamic beach and dune system. This results in changes in the shape of the beach and dunes. In our Region, video monitoring is being used to provide information on how beaches change. Check out the monitoring at Tairua and Mokau on the Cam Era website.
Many people see coastal erosion as a problem. But it is often just a part of the natural system where sand is circulated around the beach, dunes and offshore areas. Most shorelines vary between periods of sand erosion and accretion (building up). However, when these natural processes are interfered with, our coastline becomes more exposed to Coastal Hazards such as storms and flooding. There are two types of coastal erosion:
- Short-term erosion - This can be caused by storms or climate cycles without causing a permanent change in the position of the shoreline. While the area usually recovers, a full erosion and recovery cycle can take several decades.
- Long-term erosion - This is when there is a permanent change to the position of the shoreline, for example, through erosion caused by sea-level rise.
Beach animals
The animals found on open coast beaches are well adapted to live in conditions where there is constant wave action and the sand is constantly moving. These animals include shellfish such as tuatua (Paphies subtriangulata) and biscuit shells (Dosinia anus), and a variety of crustaceans1 such as sandhoppers and paddle crabs (Ovalipes catharus).
Many of the marine animals that live on open coast sandy beaches burrow in the sand in the shallow water below low tide. After storms, the shells of these animals can wash ashore in large numbers.
Our dunes and beaches are home to several birds found only in New Zealand - including northern New Zealand dotterels, banded dotterels, New Zealand pied oystercatcher, red billed gulls, black banded gulls, and variable oystercatchers. The banded dotterel and the northern New Zealand dotterel are threatened with extinction because of:
- human disturbance – people driving and walking near or over nests and young birds
- introduced predators (including feral cats, rats, mustelids, dogs and hedgehogs)
- habitat loss from introduced plants.
Restricting the access of people and their dogs to the birds’ breeding sites helps to protect these birds.
People’s effects on beaches
Many of the Region’s beaches have been modified, particularly by coastal structures such as:
These structures can affect the natural character of the beach environment. Find out more about coastal structures.
People’s recreational activities - for example the use of motor vehicles (4 wheel drives and quad bikes) - can also affect our dunes and beaches. Find out more about the impacts of recreation.
Taking care of dunes and beaches
Protect our dunes and beaches and the plants and animals that live there, by following the Dune Care Code.
Beachcare groups encourage dune care among coastal communities and work to protect and enhance the natural character of beaches and dunes.
Find out more about Beachcare groups.
Want to know more?
See our publications pages to order a copy of:
Footnotes
- Aquatic animal which has a hard outer shell instead of an internal skeleton. Typical crustaceans include crabs, shrimp and lobsters (crayfish).