February 2010

The Natural Values of South Australia's Marine Environment When most people think of Australia’s marine environments, they immediately think of the warm water, tropical regions of Australia, particularly the coral reefs of northern Australia.

But did you know that southern Australia’s coldwater or temperate marine environments are more diverse and unique in many ways than the Great Barrier Reef? Read on to find out why.

Marine Biodiversity – the variety of life southern NSW. This provides for a much larger area in our coasts and oceans and range of coldwater habitats and associated species to develop. Southern Australia’s waters contain some of the highest levels of marine biodiversity in the world. ‘Marine Secondly, the marine life of southern Australia has biodiversity’ is the term used to describe the variety of remained isolated since the Australian continent broke plants, fish and other animal species found in our waters. away from "Gondwanaland" and drifted north to the equator. While the marine fauna and flora of tropical While the diversity of mangroves, corals and fish dominate the warm tropical waters of Australia, the cold Australia mixed with the Indo-Pacific region, the marine waters of southern Australia contain more seaweeds life of southern Australia remained isolated for over 65 (algae), seagrasses, bryozoans (lace corals) and ascidians million years. This has allowed many marine species to (sea squirts) than most other places in the world. evolve their own unique characteristics. In fact, southern Australian waters support more than Marine Ecosystems of South Australia 6000 species of invertebrate animals, 1200 species of In South Australia’s 60,000 km2 of State waters, you will plants (including at least 12 species of seagrasses), find some of the largest range of marine ecosystems in 350 fish species, 16 breeding seabird species and 33 temperate southern Australia, examples of our spectacular mammal species. ecosystems include: South Australia’s rich diversity of marine life is a • the swell-dominated kelp forests of the south east; result of it’s unique south-facing coastline, it’s varying • towering cliffs and high energy beaches of the Great oceanographic conditions (eg. currents, upwellings, gulfs) Australian Bight; and the wide variety of coastal and marine environments and physical conditions - from high energy, swell- • deep water sponge gardens of Backstairs Passage dominated, rocky cliffs and sandy beaches, to the shallow, (between Cape Jervis and Kangaroo Island) and sheltered seagrass and mangrove areas of the gulfs. Thorny Passage (off Port Lincoln); • rocky coastlines and adjacent reefs characteristic of our Endemism – many of our marine species headlands and offshore islands; are found nowhere else • mangroves, saltmarshes and seagrass meadows of ‘Endemic’ is a term used to describe a plant or animal Gulf St Vincent and Spencer Gulf; that is found only in that region. In the cold waters of • the sheltered lagoons of the Coorong; southern Australia, approximately 85 - 90% of all marine • A variety of offshore islands including Pearson Island plants and animals found in the region are endemic. and the Nuyts Archipelago. In contrast, only 10-15% of the marine life found in the tropical regions of Australia is unique to Australia. The species and habitats of South Australia’s marine and coastal ecosystems are formed and maintained by a range Scientists believe there are a number of reasons for this. of natural ecological processes. First, compared to other large land masses in the southern hemisphere, most of which are ‘V’ shaped, Australia has a long coastline, stretching from south western WA to

For more information visit: www.marineparks.sa.gov.au or call 1800 006 120 Did you know? • The seagrasses of Gulf St Vincent (1530 km2) and Spencer Gulf (3700 km2) represent some of the largest temperate seagrass ecosystems in the world. • South Australia has the largest mangrove forests in southern Australia (230 km2), which are critical nursery, feeding and breeding areas for a wide range of species. • Northern Spencer Gulf contains tropical animals and plants that represent relics from an earlier time when the South Australian climate was warmer. • The head of the Great Australian Bight is one of the most important breeding and calving sites for the southern right whale in Australia and the world. The Australian population is estimated at 400-600 individuals. • South Australia’s waters are home to 80% of the world’s population of the Australian sea lion. The Pages Islands, Dangerous Reef and Seal Bay (Kangaroo Island) represent the largest breeding areas for this mammal in the world. Numerous small breeding colonies were recently discovered along the Nullarbor Cliffs in the Great Australian Bight Marine Park. • The low-lying tidal areas of Gulf St Vincent and Spencer Gulf provide habitat for some of the largest areas of mangrove, saltmarsh and associated seagrass communities in southern Australia, with a total of 820 km2. • The ornately camouflaged leafy sea dragon and many other species of seahorses, pipefish and pipehorses are unique to southern Australia, often reaching their greatest abundance in South Australia. • Upper Spencer Gulf is home to the most significant known breeding aggregation of cuttlefish on our planet. • The cold, nutrient-rich, ocean upwelling in the south east (from Robe to Port MacDonnell) is one of the most significant upwellings along the southern coast of Australia, and contributes directly to the high levels of productivity of the region. • South Australia’s location as a transition zone between the warmer waters of Western Australia and the cold waters of Victoria and Tasmania makes it a species melting pot.

For more information visit: www.marineparks.sa.gov.au or call 1800 006 120