In South Australia there are eight defined marine bio-regions and six concurrent marine planning areas. A bio-region is recognized by its distinctive biodiversity.
Our marine environment is significant as it contains some of the most productive waters along the whole of the Southern Australian coastline. Offshore currents and persistent winds draw the less dense warm surface water away from the shoreline. This results in the deeper, cold, dense and nutrient rich waters rising to the surface encouraging productivity.
Our marine environment is dominated by a diversity of fringing intertidal and subtidal reef systems, including calcarious platform reef systems of various depths, forms and covers. Abundant crevices and microhabitats exist amongst the reefs for a variety of organisms and invertebrate fauna. Reefs, seagrass meadows, kelp forests and sandy bottoms provide an interesting mixture of surroundings within the South East near-shore marine environment.
This setting also contains one of the highest centres of algal diversity in the world. Two distinct physical marine environments meet offshore from Robe creating a rich and irreplaceable ecological entity or biota. Two of the eight bio-regions meet (Otway and Coorong) and encompass the whole extent of marine waters in the South East.
The structure of the marine flora and fauna of the cold temperate Otway bioregion is unique in South Australia, with the lower temperatures favouring a definite suite of biotic species. The warmer waters of the Coorong moving west along the coast witness a change from limestone and boulder reef communities to a barrier coast environment and associated lagoons and wetlands of international importance.