During this time, Australian fishing activities diversified through the development of new fisheries and fishing technologies. Australia has the world's third largest fishing zone covering 11 million square kilometres and extending 200 nautical miles out to sea. Despite this impressive size, Australia only ranks 52nd in the world in terms of tonnes of fish landed due to the low nutrient levels in Australia's waters. Western Australia, the Commonwealth, South Australia and Queensland are the largest producers in terms of the gross value of fish. Australian waters contain over 150 fisheries, most of which target high-value species such as lobsters, prawns, abalone and tuna.
Many fisheries operate on a multi-species basis.
The most valuable Australian fisheries include the Western Rock lobster, Northern Prawn, Southern Bluefin Tuna and South East fisheries. Australia is now developing a significant deepwater trawl capacity for Patagonian toothfish in the Southern Oceans and a high seas longline capacity on the west and east coasts, targeting high quality tuna and swordfishes. Aquaculture Aquaculture is the farming of fish and other aquatic animals and plants in marine and freshwater environments. Aquaculture is now one of Australia's fastest growing rural industries. Currently more than 60 species are being farmed including pearl oyster, pacific and Sydney rock oysters, mussels, prawns, freshwater crayfish, native fish, salmon, tuna, eels, crocodiles, and algae.