AUSTRALIA – a Wide Brown Land
Australia’s mangroves are found in all mainland States and Territories with coastal boundaries, including Western Australia, the Northern Territory, Queensland, New South Wales, Jervis Bay Territory, Victoria, and South Australia. Mangroves are not present in Tasmania.
Click on any of the States above to view further detail of mangroves in each.
Australia has the third largest area of mangroves in the world after Indonesia and Brazil, totalling around 11,500 km2 representing approximately 6.4% of the world’s total mangrove area. The larger forested areas of Australia’s mangroves, approximately 75%, occur in the humid tropics to the north where human population densities are low. However, there are notable areas of mangroves in temperate regions as far south as Corner Inlet in Victoria around 38° S. This is the most southerly and highest latitude site of mangroves in the world. These southern stands consist entirely of one species, Avicennia marina, a member of the plant family Avicenniaceae.
Contrasting temperate & tropical mangroves
Avicennia marina dominates the temperate south coast, while Rhizophora species dominate the tropical north. Distributions of mangrove species are affected by climate, with most restricted to warmer wetter areas of the north.
Exceptional biodiversity & distributional limits
Australia’s mangroves show exceptional biodiversity, comprising 58% of species in the world. Australia has one endemic species, Avicennia integra, and a number of rare and uncommon species, hybrids and varieties. Australia’s mangroves also occupy the most southerly, and highest latitude, location for mangroves in the world.
Isolated & well protected
Australia’s mangroves are largely low-impacted and protected by their isolation. They are rarely exploited directly and most occupy the least populated northern coast. There are however localised impacts and pressures around estuary ports, and with urban development associated with recent sea-change resettlement to coastal areas.
More on Australia’s Mangroves
Another mangrove family, the Rhizophoraceae, dominates the vast northern coastline. Australia is one of the world’s largest countries, with a land area of over 7.7 million km2. The country spans 33° latitudinal range between tropic and temperate zones from Cape York, around 10° S, to just south of Hobart, around 43° S. By longitude, the country spans 41°, more than 5000 km. Australia is also the world’s driest inhabited continent. Bordering the coast of this vast dry land, mangroves exist as a relatively thin line hugging sheltered areas, including numerous islands and mainland enclaves. Around 70% of Australia’s mangroves occur within the reported 974 catchment estuaries (Ozestuaries 2006).
Greater Awareness and Emerging Pressures
The Australian coastline although relatively lightly populated, compared with other large countries with mangroves, has over 85% of its population living within 50 km of the coast. This reflects the coastal lifestyle that is an integral part of the Australian identity. Furthermore, the trend to move to the coast continues, with all States and Territories reporting their highest population growth rates within 3 km of the coast. Therefore, one of the emerging great challenges of the 21st century is the need to mitigate current environmental damage and disturbance, while addressing the growing threats to diminishing natural habitats like Australia’s amazing mangroves. In the following pages, the extraordinary wonders and numerous benefits of Australia’s mangroves are described and explored, along with the factors that influence their health, growth and distribution. Australia’s mangroves, like never before are facing the challenge of a rapidly changing, dynamic world. Implicit in this, and in consideration of the factors that influence mangrove diversity and growth, is how these growth limitations ultimately define the vulnerability of each species to changes taking place within the unique natural environment of mangroves.
Welcome to the dynamic world of Australia’s Mangroves!