The decrease was a small sign of improvement after years of steadily deteriorating safety at sea. Last year, sea attacks world-wide surged by 39% to 406 cases, the highest in six years, with Somali pirates' raids on vessels accounting for more than half of the incidents.
Somalia has been ravaged by violence and anarchy since 1991, fueling a piracy boom that has made its coastal waters among the world's most dangerous. Particularly perilous is the Gulf of Aden, which is connects the Red Sea to the Indian Ocean and is the world's busiest sea lane.
But the number of attacks world-wide fell to 196 between January and June of this year, down from 240 incidents in the comparable period a year earlier, the International Maritime Bureau's piracy reporting center in Kuala Lumpur said in a statement.
It said attacks dropped to 33 in the Gulf of Aden from 86 a year earlier. However, it said attacks in the Somali basin—that is, the country's coastal waters, excluding the Gulf of Aden—and the wider Indian Ocean have risen to 51 from 44 a year earlier as pirates shifted attention to other areas.
"The actions of the navies in the Gulf of Aden have been instrumental in bringing down the attacks there. The Indian Ocean poses a different challenge," warned the bureau's director, Capt. Pottengal Mukundan.
An international flotilla, including U.S. and European warships, has been deployed to the Gulf of Aden and prevented many hijackings, most which were opportunistic in nature, with some pirates paid multimillion-dollar ransoms.
The bureau said that globally, 70 vessels were boarded and 31 hijacked during the first half of the year, with 597 crew members taken hostage and one killed.
Of the hijacked vessels, 11 were seized by Somali pirates in the Gulf of Aden and 16 more in the wider Indian Ocean region. The maritime bureau said Somali pirates had increased their capability by hijacking vessels farther into the sea.
In other areas with significant attacks over the first six months, there were 16 raids in Indonesia, 15 in the South China Sea, 14 in the Red Sea and nine in Malaysia.
The island nation Seychelles announced Thursday that it has signed an agreement with the U.S. to accept suspected pirates for prosecution who are detained in the waters off East Africa. The U.S. Ambassador to Seychelles, Mary Jo Wills, said the U.S. is grateful that countries such as Seychelles and Kenya accept pirates for prosecution.