Gazania is a plant which grows along the ground. The leaves are green on the upper side and have a whitish felt on the underside. Flowers on the gazania are yellow orange and are 5-8 cm in diameter. The fruits on the Gazania are hairy and have a series of scales at the top. This plant flowers in summer and is found in many gardens as well as on the dunes.
Gazania plants grow low to the ground which helps it to be protected against strong winds. The leaves grow rather small so that there is a smaller surface area for the sun to extract moisture from and the leaves also have a white underside to protect them from the salt and also to help stop large amounts of evaporation.
Euphorbia is a native plant to the dune area. The plant inside has a milky latex which can be seen when broken. These plants have a fascinating and unique floral structure as the tiny looking flowers are actually a group of even smaller flowers. The flowers are surrounded by four, white bordered petal structures which are attached to a green cup. It grows to a height of one metre and has 15mm leaves which are dense and oblong. The leaves often have a red tinge and near the top of the stems become more circular.
Coastal Rosemary is a native dark green shrub. It grows to the height of two metres tall. The leaves are straight and are arranged in a whorls of four, they are 25mm long and have a grey underside. The flowers on the shrub are a white to mauve colour and grow to about 15mm long. Coastal Rosemary is often found on cliffs although it is common all throughout the sea area, it flowers almost all year round.
The shrub is able to survive because it’s branches are flexible and the upper leaves are able to shelter the base of the plant to give the roots shaded and not give off too much moisture. The leaves are designed small so that each leaf has a small surface area and have only a low evaporation rate. Although the coastal rosemary is not low lying, it has a large root system which holds it firmly into the sand as well as holding the sand together in to form sand dunes.
Port Noarlunga – Coastal Protection
At Port Noarlunga there are many plants growing in the sand dunes which protect the sand dunes from being washed away or blown away by the wind. Some of the beach plants are marram, sea rocket, Spinifex, pigface, euphorbia, coastal rosemary, gazania and roots. These plants are all fore dune plants and hey are mostly all small and low lying. Fore dune plants are able to survive living on the beach because they are succulent, they extrude the salt and they grow on runners. As the fore dune plants are able to survive these conditions they make it easier for more delicate and less adaptable plants to grow on the primary and secondary dunes because they provide shelter and humus for these plants.
Coastal protection is making it easier for the fore dune plants to grow and also protecting the sand dunes by bringing in laws and rules, building special structures and general coastal protection for example, cleanups and education services.
Some of the structures built are:
Carparks- to direct people into one area going down to the beach. Near the car park is most likely a board walk or trail for people to walk down to the beach on instead of walking over the sand dunes.
Board walks – The board walks are put in throughout the beach to encourage people to walk on them instead of on the sand dunes. These are placed consistently along the beach so people do no thave to walk too far and decide to walk down to the beach over the sand dunes because a board walk is too far away.
Fences – Fences are put up around the sand dunes to stop people walking over them. This gives the sand dunes a real chance to develop fore dune plants on them.
Signs are placed over the beach, with restrictions and laws on them. If people disobey these laws, large fines are needed to be paid or sometimes the person can go to jail. Other signs are informing that coastal protection is being used in the Port Noarlunga area and to be considerate of the wildlife.
Witton Bluff – Rip Rap
The cliff at Witton Bluff had been undergoing a lot of erosion and now a protection scheme has been built to help prevent the cliff from eroding. Coastal protection is used to stop cliffs from eroding, a few different methods have been experimented with, but the protection used at Witton Bluff called ‘Rip Rap’ is the best method.
Irregular shaped rocks are placed in front of the cliff to absorb the waves energy and slow the wave. Under the rocks is a wire mesh and under that is a mixture of sand and gravel, these all act as filters to slow the wave and return it slowly to the beach and ea. The reason why this method is used is because the method of using large rocks is very unsightly which is the same with concrete walls, but the concrete walls also destroy the beach because the reflected waves remove the sand. Rip Rap causes the cliff base to still look natural as the rocks are placed in an effective way as well as stopping the cliff from eroding and protecting the beach at the same time.
The cliff at Witton Bluff is now more likely to erode from wind erosion not wave erosion.