Somali pirate attacks have fallen to the lowest level since 2006, but ships face a surge in violent incidents off the coast of West Africa, the International Maritime Bureau said.
The London-based IMB recorded 138 acts of piracy in the first six months of 2013, down from 177 in the same period last year.
There were seven hijackings, compared with 20 a year earlier, and the number of mariners taken hostage fell to 127 from 334 in the first six months of 2012.
But there was a sharp increase in piracy in the Gulf of Guinea with 31 incidents and four hijackings so far this year, with attacks off Nigeria accounting for 22 of the incidents.
By contrast, there were just four reported incidents off the Somali coast in the first half of the year, against 44 a year earlier.
“There has been a worrying trend in the kidnapping of crew from vessels well outside the territorial limits of coastal states in the Gulf of Guinea,” said IMB director Pottengal Mukundan.
“In April 2013, nine crew members were kidnapped from two container vessels, one of which was 170 nautical miles from the coast. Pirates have used mother ships, some of which were smaller off-shore supply vessels hijacked by pirates to conduct the attacks.”
Mukundan said there was a “significant under-reporting” of attacks again this year, which “prevents meaningful response by the authorities and endangers other vessels sailing into the area unaware of the precise nature of the threat.”
The IMB attributed the decline in Somali attacks to actions by international navies, as well as preventative measures by some merchant vessels, including the deployment of privately contracted armed security personnel.
As of June 30, Somali pirates were holding 57 seamen for ransom on four ships. They were also holding 11 kidnapped crew members on land — four since April 2010 and seven since September 2010.