A report on the general situation in the Australian tugboat industry can be found in the AIMPE Annual Reports section of this website.
Australia's international trade is dominated by exports of bulk commodities - particularly iron ore and coal. The ships taking these cargoes to their destinations (mainly north east Asia) are very large vessels. They require the assistance of powerful tugs on arrival into port, to assist on departure and at other times too. Here is a slideshow of tugs from around the coast: