Oceans

Powerful volcanic eruptions over the last century have slowed the rise in sea level by releasing fine particles that deflect sunlight, cooling the oceans and thus reducing their volume, according to a study published Thursday in the journal Nature. But the effect is only temporary. Using computer models and satellite data, researchers found that the 1991 eruption of Mt. Pinatubo in the Philippines dropped sea levels by about 5 millimeters, or a fifth of an inch, within a year.

An underwater acoustic signal was heard across the globe this week, marking a milestone in an experiment that researchers hope will make it easier to detect warming of the world's oceans from the greenhouse effect. Sounding like an underwater foghorn, five transmitters suspended 600 feet below a U.S. Navy ship in the southern Indian Ocean began booming every three hours, for one hour at a time, last Saturday.

His rough-cut hair and beard shine silver like sunlight off water. His eyes are dappled with hues of the reef. He wears a dive-suit sewn in shades of ocean blue. His name seems derived from the sea, too: Cousteau. When he splashes off the stern of a dive boat, Jean-Michel Cousteau folds at the waist. His arms draw to his side. His swim fins flex and bite into the water. He is fluid, streamlined, serene. A cascade of chrome bubbles rise from the scuba regulator in his mouth.

President Bush on Friday established a White House advisory committee to coordinate the nation's ocean policies and begin considering hundreds of recommendations from a presidential commission on how to restore collapsing fisheries and polluted oceans. Bush set up the Cabinet-level committee as part of his legally required response to the U.S. Commission on Ocean Policy; that panel of presidential appointees spent nearly three years studying the nation's oceans.

Scientists seeking to transmit loud sounds through the Pacific Ocean to measure global warming defended their experiment Wednesday, insisting that the noise would not deafen whales and pledging to halt the project if it appeared to be causing harm. "We are not out to harm a single whale with these underwater sounds," said David Hyde, director of the research project at Scripps Institution of Oceanography in San Diego. "We will cease sound transmissions to avoid harm to marine mammals."

For more than three hours last week, delegates to the world body responsible for the global ban on killing whales for profit discussed more efficient and painless ways to do just that. Norway recommended its new harpoon-borne, high-explosive grenade fired deep into the whale's brain, noting in a scientific report that 63% of the 625 whales it killed that way last year died instantly. Japan said a .

A massive ocean circulation pattern that plays a crucial role in shaping the world's climate may not have been slowing down over the last few decades as scientists previously believed, according to a study released Thursday. The perceived slowdown had been considered alarming support for computer predictions that global warming would disrupt the planet's heat regulation.

A national panel of scientists has recommended immediate and substantial reductions in ocean fishing to rebuild marine ecosystems throughout the world that are so severely depleted they are in danger of collapsing. The total volume of fish being caught has reached or exceeded the maximum amount that can be sustained by the world's oceans, the scientists reported. About 84 million metric tons of fish and other seafood are caught each year in marine waters worldwide, worth about $3.

The extremely warm ocean waters fueling this season's record hurricane season are stressing coral reefs throughout the Caribbean and may kill 80% to 90% of the structures in some areas, scientists reported Monday. These colorful undersea landmarks -- homes for tropical fish and magnets for divers and snorkelers -- are turning white, or "bleaching" in an area extending from the Florida Keys to Puerto Rico and Panama because of warmer-than-usual water that has persisted in the Atlantic for months.

President Clinton will unveil a plan today intended to permanently protect coral reefs in the northwest Hawaiian Islands and set a course that would ban fishing, offshore drilling and other activities from sensitive ocean waters, a White House official said Thursday. Clinton will order the Commerce and Interior departments to designate "marine protected areas," marked by diverse marine ecosystems.