August 23, 1986

Lake Okeechobee, giant linchpin of the water resource network of south Florida and the Everglades, is dying, and the state government is mobilizing to rescue the lake and prevent what some experts fear could be an environmental disaster. State officials were already preparing a program to protect the lake when an eruption of blue-green algae covered more than 100 square miles of its surface last week. Such huge algae blooms are considered unmistakable signs of declining water quality and a stage leading to the biological death of a lake. The loss of Okeechobee would be ''an environmental calamity of the first magnitude,'' said Pat Bidol, an official in the water district that includes the lake. The lake is considered ''the liquid heart'' of south Florida and is a reservoir for coastal cities such as Miami and Fort Lauderdale. Moreover, it has key functions in flood control and supplies water in the long dry season to the Everglades and the region's sugar cane and vegetable industries.

The Soviet Union announced economic initiatives today that signaled a new willingness to become actively involved in the commerce and politics of Western business. Moscow said it was cutting oil exports to the West by 100,000 barrels a day, or about 6 percent, at the request of Iran, a member of the Organization of Petroleum Exporting Countries. Western diplomats said it was a significant gesture of support for OPEC's efforts to stabilize oil prices. Moscow also said it had petitioned the Secretariat of the General Agreement on Tariffs and Trade to give the Soviet Union observer status at the next round of multilateral trade negotiations, scheduled to open Sept. 15 in Punta del Este, Uruguay.

Pan American World Airways has agreed to pay $1.95 million for violations of Federal regulations on aircraft safety maintenance, the Federal Aviation Administration announced today. The fine, stemming from a two-month audit of Pan American's maintenance records last spring, was the largest ever collected by the agency. Federal inspectors found that Pan American had operated planes in need of repair, had installed parts that had exceeded their approved service life and had failed to inspect planes within mandated time limits. Hundreds of Errors The Government faulted the airline on hundreds of errors, including sending a plane on 37 flights beyond the scheduled overhaul of one of its landing gears, and flying one jet 18 times despite a misalignment in the part of the wing that guides direction and movement.

An armada of Coast Guard vessels staged a ''blockade'' of New York Harbor Thursday night and yesterday, and teams of heavily armed guardsmen boarded dozens of pleasure boats and commercial vessels in search of drug smugglers. But after 22 hours of the highly unusual operation, in which more than 90 vessels were searched at random, the Coast Guard said it had found no illegal drugs. Law-enforcement officials had more success on land. In raids in Queens and the Bronx, they said, they seized heroin with a street value of $70 million. [ Page 26. ] A Warning to Smugglers The blockade was the latest in a series of highly visible law-enforcement operations in New York that the authorites said were meant to show they were getting tough on drugs. On Thursday, officers seized 45,000 glass crack pipes, and the police have begun confiscating the cars of drug buyers.

Only eight months into Mayor Koch's third term, his administration, through a combination of design, accident and duress, has undergone a staff overhaul so extensive that even the Mayor did not envision it when he jocularly promised to start the term with ''zero-based'' commissioners. Since January, when the corruption scandal began to shake the Mayor's government, 20 of 44 agency and department heads have left, some because of the scandal, some for reasons totally unrelated, some of their own volition, and some under pressure. The Mayor has argued repeatedly that an examination of the same period at the start of his second term would demonstrate the same kind of turnover. But an analysis of his own personnel records shows that there were only seven equivalent staff changes then -15 percent, compared with 45 percent now. Keeping Number Down The turnover might have been greater, but some officials who had planned to resign stayed on either because they feared being tarred by the scandal brush or to work with the mayor during the crisis.