Captain Bruce Legge, the director of operations of the multinational Combined Maritime Forces (CMF), said the International Maritime Bureau reported just one attempted attack by Somali pirates between July and September this year, compared with 36 in the same period last year.

CMF is a coalition of 25 nations based in Bahrain in the Persian Gulf. It includes two task forces - Combined Task Force 150 (CTF-150) responsible for counter-terrorism and security activities, and CTF-151, responsible for counter-piracy.

The latest figures were encouraging but did not signal an end to piracy nor a dramatic improvement to maritime security in the region, Captain Legge said.

"Our area of responsibility here stretches across a challenging 2.5 million square kilometres, an area about the size of mainland Australia," he said in a statement.

"The decrease in piracy is due in a large part to the ongoing co-ordinated efforts of the CMF counter-piracy Taskforce 151, with the Task Forces from the EUNAVFOR (European Naval Force) and NATO (North Atlantic treaty Organisation)."

Captain Legge said Australia always had a warship conducting maritime security patrols in this area, currently HMAS Anzac.

Local factors played a part in the reduction in pirate attacks, including increased awareness of piracy by merchant ships and fishing vessels and the south-west monsoon period which prevents pirates getting off the beach in Somalia.

"Nonetheless, the encouraging fact is that we are not seeing a dramatic upsurge in piracy now that the monsoon season has ended," he said.