Sea piracy worldwide fell to its lowest level since 2008 over the first nine months of this year as navies and shipping companies cracked down on attacks off the coast of Somalia, an international maritime watchdog said Monday.

The International Maritime Bureau said 233 attacks were recorded worldwide in the first nine months of this year, down from 352 in the same period last year. The bureau's piracy reporting arm, which is based in Kuala Lumpur, said 24 vessels were hijacked worldwide between January and September 2012, with 458 crew members taken hostage and six killed.

The numbers fell because attacks off Somalia's coast plummeted during that same period, from 199 last year to 70 this year. The bureau said only one Somali attack was reported in the entire third quarter of 2012.

Piracy soared in 2009 because of attacks off largely lawless Somalia, where pirates became more daring and desperate. Since then, pirates have been deterred by international navies, and by ships taking their own security measures, such as hiring armed guards.

A recent trip by Associated Press reporters to areas of the Somali coast once controlled by pirates found many of them hiding from creditors in unfurnished rooms. Rather than attacking cargo ships, they were playing cards, or catching lobsters.

"We welcome the successful robust targeting of pirate action groups by international navies in the high-risk waters off Somalia, ensuring these criminals are removed before they can threaten ships," said IMB director Pottengal Mukundan. But he added that the waters "are still extremely high-risk and the naval presence must be maintained."

The bureau said piracy in Africa's Gulf of Guinea, ranging from Benin to Togo, was becoming increasingly dangerous, with 34 cases in the first nine months. It said the attacks were often violent, planned and aimed at stealing refined oil products.

Mukundan said 21 attacks were recorded in Nigeria alone, but he praised the country's navy for helping to rescue vessels. He said many navies in the vast gulf don't have resources to fight piracy far out at sea, allowing gangs to shift their operations to other areas.

In Asia, the bureau said Indonesia reported 51 attacks in the first nine months this year, up from 46 for the whole of 2011. It also warned ships to be alert in Malacca Straits, South China Sea and around Malaysia; each of those areas has reported a hijacking this year.