Mandora Marsh facts for kids
Mandora Marsh, also known as Mandora Salt Marsh, is a large and diverse wetland system in Western Australia. It is located very close to Eighty Mile Beach. This special area is part of the Eighty Mile Beach Ramsar Site, which means it's recognized internationally as an important wetland. The marsh is found at the western edge of the Great Sandy Desert and is inside a large farming area called Mandora Station. Mandora Marsh and the nearby Anna Plains Station are considered an Important Bird Area by BirdLife International. This is because many different kinds of waders (birds that wade in shallow water) and waterbirds use this area.
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What is Mandora Marsh?
Mandora Marsh formed over thousands of years. It used to be the lower part and estuary (where a river meets the sea) of an ancient river. The main parts of the marsh are two big lakes. These lakes fill up with water after heavy rain from cyclones.
Lake Walyarta
The western lake is called Lake Walyarta 19°46′S 121°17′E / 19.767°S 121.283°E. It's a claypan, which is a flat area of hard clay that holds water. This lake stretches about 30 kilometers east from the Great Northern Highway. Even though it can be up to 5 kilometers wide, the water in Lake Walyarta is never deeper than 2 meters.
The Eastern Lake
The eastern lake 19°47′S 121°35′E / 19.783°S 121.583°E is separated from Lake Walyarta by a calcrete ridge. A calcrete ridge is a natural bank made of hardened calcium carbonate. This eastern lake is a wide, braided area with many small channels and islands of plants. It floods a lot but then dries out quickly. When it dries, it leaves behind many isolated salt and claypans.
Salt Creek
Connecting the two lakes is Salt Creek. This creek is about 5 kilometers long and 20 meters wide. It has mangrove trees growing along its banks. Salt Creek always has water, and it seems to be fed by many soaks. Soaks are places where groundwater comes to the surface.
Freshwater Springs
Even though it's called a "salt marsh," Mandora Marsh also has many permanent or almost permanent freshwater swamps. These swamps are fed by springs along the southern side of the two main lakes. These springs often form a raised mound, about 2-3 meters high, made of wet peat. Peat is a type of soil made from decayed plants. These mounds support trees like Melaleuca and Sesbania. Mangroves grow near the springs that have salty or slightly salty water.
The springs vary in size, from small areas of 0.1 hectares to several hectares. Each spring mound is usually surrounded by a moat (a ditch of water). This moat can be up to 50 centimeters deep, or just have shallow pools or wet soil. Many springs also have small groups of cumbungi plants. The plants growing underneath are sometimes dominated by the fern Achrostichum speciosum.
You can find thick groups of saltwater paperbark trees where floodwaters stay the longest. Water bores (holes drilled for water) have been set up in these areas. The watering troughs are used by waterbirds all year round. The most amazing spring is Mandora Soak, which is a raised peat bog that is thought to be 7000 years old!
Flora and Fauna
Mandora Salt Marsh is home to many different plants and animals.
Plants of Mandora Marsh
About 269 different kinds of vascular plants have been found at Mandora Salt Marsh. Vascular plants are plants that have special tissues to carry water and nutrients. These plants belong to 55 different plant families. This includes 37 species from the Poaceae, which is the true grass family. There are also nine types of introduced weeds.
One interesting plant fact is that the most inland place where mangroves grow in Australia is right here in Mandora Marsh. There's an isolated group of grey mangroves in the eastern lake, about 60 kilometers inland from Eighty Mile Beach. A new species of bush tomato, called Solanum oligandrum, was first described in 2001. It is only known to grow in the Mandora Marsh area.
Animals of Mandora Marsh
A total of 55 different kinds of waterbirds have been seen at the marsh. At least 13 of these species have been recorded breeding there. Some common waterbirds include the black-winged stilt, whiskered tern, grey teal, white-necked heron, and great egret. When floods make conditions right, many Australian pelicans and black swans also breed there.
The threatened bilby has been seen in the sandy parts of the marsh. The bilby is a special animal protected by the Australian government. In total, 22 species of mammal, 49 types of reptiles, and six kinds of frogs have been recorded at Mandora Marsh. A new species of goby fish was also discovered in Salt Creek!
Traditional Ownership
The Mandora Marsh is very important culturally to the Nyangumarta people. They are the traditional owners of this land.
Conservation Efforts
Unfortunately, grazing by cattle has caused a lot of damage to the plants and the environment around the springs and Salt Creek. To help stop this damage, Saunders Spring was fenced in 1997, and Grants Spring was fenced in 2001. There are also many feral camels and cats in the marsh, which can harm the native wildlife.
Images for kids
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Black-winged stilt
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Bilby
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Australian feral camel
