Oxygen

"Dead zones" in the Chesapeake Bay - areas with so little oxygen that fish can't live - grew to cover a record portion of the estuary last summer, according to a federally funded monitoring program. An average of 5 percent of the bay was classified as "anoxic" during the summer months, meaning the water had almost no dissolved oxygen, researchers from the Chesapeake Bay Program reported yesterday. The lack of oxygen suffocates oysters and drives fish and crabs in search of water where they can breathe.

ON THE CHESAPEAKE BAY - Motoring through lifeless waters, charter boat captain Richie Gaines suddenly ran into a patch boiling with hundreds of silver-bellied rockfish, packed together so tightly they were leaping out of the water. Tails thrashed. Seagulls shrieked and dove at the feast near the mouth of the Chester River. Gaines unholstered his fly rod, plucking out 27 fish in just a few minutes, reeling in another with nearly every cast. He might have been delighted - but instead he found the thicket of fish disturbing.

The low-oxygen "dead zone" in the Chesapeake Bay spread this month to cover 41 percent of the estuary, the second-worst reading for August in recorded history, according to scientific data released yesterday. The dismal results followed a report in July from the federal- and state-funded Chesapeake Bay Program that 36 percent of the bay's main section had less than 5 milligrams per liter of dissolved oxygen, a level that ranked among the worst for that month in a quarter-century of monitoring.

MOSCOW - Seven sailors aboard a miniature Russian submarine that sank off the Kamchatka Peninsula on Thursday were still trapped in the cold, dark waters of the North Pacific early today, as their air supply steadily dwindled. The stubby, red-and-white-striped Priz tangled its propeller in fishing nets during naval exercises and sank in 625 feet of water, a Russian navy spokesman said. The accident triggered an international rescue effort joined by Britain, Japan and the United States.

More than a third of the Chesapeake Bay was a low-oxygen "dead zone" during monitoring this month, meaning the nation's largest estuary is on pace to have one of its most unhealthy summers on record, according to data released yesterday. "The things we love to eat out of the bay will not do well with this kind of summer," said Bill Dennison, ecologist at the University of Maryland Center for Environmental Science. "Oxygen is a crucial part of the environment for the fish and crabs and oysters, and having low oxygen or no oxygen is just as devastating for them as bulldozing a forest is for other creatures."

This summer, as scientists with the state and federally funded Chesapeake Bay Program follow their annual ritual of reporting on the size of the low-oxygen "dead zone" in the Chesapeake Bay, they will be using a more relaxed standard of what "low oxygen" means. Some environmentalists are concerned that the Environmental Protection Agency's move will weaken water-quality standards in a way similar to what the Ehrlich administration tried this spring, before backing off last month under heavy criticism.

The Chesapeake Bay this summer is expected to suffer its worst season for oxygen-starved "dead zones" in seven years, according to a new projection by a group of scientists. Heavy rainfall this spring flushed significant amounts of fertilizer and other pollutants into the bay, and they are expected to stimulate algae blooms that devour oxygen, creating an unhealthy habitat for fish, oysters and crabs, said researchers with the Chesapeake Bay Program, which is funded by the federal government and six states in the bay watershed.

ISSUE: The conservation group American Rivers recently cited raw sewage, mine runoff, slashed cleanup funds and a proposed inflatable dam near Wilkes-Barre, Pa., in declaring the Susquehanna River "America's most endangered river." PRO: "The volume of untreated and poorly treated sewage that ends up the river is a serious threat to the health of the river and everyone who wants to enjoy it - and the problem is poised to get worse," said Rebecca R. Wodder, president of American Rivers. One University of Maryland consultant has estimated that the river contributes 40 percent of the nitrogen and 20 percent of the phosphorus, both key ingredients in fertilizers, to the bay. These nutrients fuel algae blooms that take oxygen from bay water, killing fish, shellfish and plants.

It was a standard 30-minute hospital procedure, but it grabbed the world's attention overnight. Doctors in Rome performed a tracheotomy yesterday on Pope John Paul II - making an incision in his neck below the larynx and inserting a tube that can provide oxygen to his lungs and help clear fluids or other obstructions from his airway. The 84-year-old pontiff reportedly was breathing with the help of a mechanical ventilator. A Vatican spokesman described yesterday's procedure as "elective" and said the surgery had had a "positive" outcome.

U.S.- Russian crew on way to 6-month space mission BAIKONUR, Kazakhstan - A rocket carrying two Russian cosmonauts and an American astronaut to the International Space Station streaked into orbit yesterday, the latest flight of a Russian space vehicle to fill in for grounded U.S. shuttles. The spaceship is due to dock with the station tomorrow at 8:17 a.m. Moscow time. During the six-month mission, the new crew will do experiments to research new AIDS vaccines, study plant growth and go on at least two space walks.