Plant
Algae comprise several different groups of organisms which produce food by photosynthesis and thus have traditionally been included in the plant kingdom. The seaweeds range from large multicellular algae to single-celled organisms and are classified into three groups, the brown, red and green algae. There is good evidence that the brown algae evolved independently from the others, from non-photosynthetic ancestors that formed endosymbiotic relationships with red algae rather than from cyanobacteria, and they are no longer classified as plants as defined here.
Agriculture in Australia
The shorelines, especially the Great Barrier Reef, are providing motivation to help the continent by using seaweed (algae) to absorb nutrients. Because of the giant number of natural Australian seaweeds, not only could seaweed cultivation be used to help absorb nutrients around the GBR and other Australian shores, cultivation could also help feed a large part of the world. Even the Chinese, who could be considered far more advanced in seaweed cultivation, are interested in the future of Australian seaweeds. Lastly, the GBR itself, because of the delicate corals, has lent itself to utilizing seaweed/algae purposely as a nutrient reduction tool in the form of algae. This has occurred in the form of algae scrubbers, and seaweed cultivators, which are now available for domestic use worldwide.