WASHINGTON, D.C.

Oceans stripped of fish

Scientists reported a 90 percent decline in large predatory fish in the world’s oceans since a half century ago, a dire assessment that drew immediate skepticism from commercial fishermen.

Analyzing nearly 50 years of data, two marine scientists at Dalhousie University in Canada said that commercial fishing killed off all but 10 percent of populations of large prized tuna, swordfish, marlin and other fish species. Average weights of those remaining also have declined sharply, they said.

“Although it is now widely accepted that single populations can be fished to low levels, this is the first analysis to show general, pronounced declines of entire communities across widely varying ecosystems,” scientists Ransom A. Myers and Boris Worm report in today’s issue of Nature magazine.

The trends outlined in the report echo a 1994 estimate by the U.N. Food and Agriculture Organization that almost 70 percent of marine fish stocks were overfished. A U.N.-sponsored world summit in South Africa called for restoration of global fisheries by 2015.

Pakistan

String of explosions hits gasoline stations

Attackers on a motorcycle planted explosives and set off a series of explosions early today at 12 Shell gas stations in southern Karachi, police said. There were no injuries.

Over three hours, two men on a motorcycle went from one station to the next, placing the explosive devices in garbage cans, police spokesman Malik Sheikh said. The blasts began at 4 a.m. local time, he said.

No one claimed responsibility for the attacks, but law enforcement officials who have raided militant organizations have seized maps of Karachi with Shell stations marked as possible targets.

Royal Dutch-Shell Group is a British-Dutch firm based in London — but like many Western-owned businesses in Pakistan, it is frequently mistaken for a U.S. company.