What was going on when I was born?

Algae covering Peconic Bay throughout the summer have destroyed the commercially valuable scallop crop here on eastern Long Island, scientists and baymen said this week as scallopers prepared to begin their annual harvest. They added that the damage was so extensive, that the future of scalloping in the bay, one of the richest scalloping areas on the East Coast, was endangered. In effect, they said, the scallops are starving. The algae have been so successful in the bay that they have supplanted the organisms that the scallops normally feed upon. The microscopic, hatbox-shaped diatoms that compose the algal bloom, or large-scale spread of algae, are too small for scallops to digest.

President Reagan today called on Mikhail S. Gorbachev, the Soviet leader, to translate his publicly stated readiness for sharp cuts in nuclear forces into ''concrete proposals'' at the Geneva arms talks, which resume next week. He said such a move could produce ''a positive additional stimulus'' to their meeting Nov. 19-20 in Geneva. Mr. Reagan met for 30 minutes today at the White House with the chief American arms negotiator at Geneva, Max M. Kampelman, who also is in charge of the space defense talks; former Senator John G. Tower, who heads the delegation to the strategic arms talks, and Maynard W. Glitman, who heads the team for the talks on medium-range arms. 'Unprecedented Authority' In a statement issued by the White House after Mr. Reagan's meeting, the President said his team in Geneva had ''unprecedented authority'' to negotiate flexibly. ''There is no reason why a serious reduction process cannot begin promptly,'' he said.

White South African businessmen and newspaper editors held talks in Zambia today with leaders of the main rebel group opposed to white minority rule in South Africa. The encounter, which President P. W. Botha has branded as a betrayal, brought together business leaders, mostly from the Anglo American Corporation, the country's biggest mining company, and leading figures from the outlawed and exiled African National Congress, which seeks the overthrow of white rule in South Africa. White opposition figures inside the country, meanwhile, welcomed proposals Thursday by a Government-sponsored panel for dismantling apartheid legislation that restricts blacks' rights to move to the townships set aside for them in urban areas. Proposal Is Criticized But the most prominent black opposition movement, the United Democratic Front, said the proposed changes would not dent ''white power and privilege,'' while other opponents said more changes would be needed to defuse the nation's racial confrontation, which has taken about 680 lives in a year of violent unrest in the black townships.

A Soviet intelligence operative whose defection led Thursday to an order for the expulsion of 25 Russians from Britain had been working for Britain as a double agent for nearly 20 years, Western intelligence sources said today. It was also learned from British officials that the agent, Oleg A. Gordiyevsky, defected in late July or early last month because he feared that his cover had been destroyed. The officials said he believed that his life would be in danger if he remained at his post as head of the London mission of the K.G.B., the Soviet intelligence agency, for even a few more days. The timing of his departure from the mission indicated that his decision was not connected with the recent defection of the West German senior counterespionage officer, Hans Joachim Tiedge, who fled to East Berlin at least two weeks after Mr. Gordiyevsky's defection.

President Reagan's special representative on acid rain told the governors of six New England states today that he believes the problem is caused by sulfur emissions from industry and that he will recommend a cleanup program. The envoy, Drew Lewis, said that while some scientific questions remained, ''it seems to me that saying sulfates do not cause acid rain is the same as saying that smoking does not cause lung cancer.'' The Administration has argued that more study is needed to justify the expense of national action to reduce sulfur emissions from the smokestacks of factories and power plants. Around the nation, but especially in the Northeast and in eastern Canada, scientists have linked the death of fish and the decline of forests to the acidity of rainfall.

An Air Force missile destroyed an orbiting derelict satellite 290 miles above the Pacific Ocean today in the first such test of an anti-satellite weapon. The Air Force said the heat-seeking missile, carried into space by a rocket launched from an F-15 fighter plane, homed in on a 6-year-old Air Force satellite orbiting at 17,500 miles an hour. The Air Force said the missile struck the satellite at 4:42 P.M. Eastern standard time. ''From everything that we can tell, it went absolutely flawless,'' Lieut. Gen. Bernard P. Randolph, Air Force deputy chief of staff, said at a news conference.

Twisting a handkerchief nervously in her hand, one woman recounted how a younger sister had been shot four times in the back by her husband. When asked to arrest the man, she said, a police official remarked indifferently that the victim must have committed adultery. Another woman in her mid-20's said between sobs that she was being terrorized by a former lover, a man with an extensive criminal record who had threatened to kill her if she did not live with him again. She said she went to the police, who advised her mockingly to ''get a sharp knife and stick it in his gut.'' Neither woman, though, seemed surprised by the reaction of the police. The inclination of police and judicial authorities here to view violent acts against women as justifiable ''crimes of passion'' has been such that, until now at least, many women never bothered to report rapes or beatings.

A revealing moment in what has come to be called the Rainbow Warrior affair - the sabotage of the flagship of the Greenpeace environmental group in New Zealand in July - came here the other day when Prime Minister Laurent Fabius, appearing in a 90-minute television interview, answered questions from the French television audience. One caller raised the matter of the Rainbow Warrior, but it was not to ask if French intelligence agents had sunk the vessel - an accusation being made by the New Zealand Government - or whether France had abused its power in the affair. Rather, the caller wanted to know whether Mr. Fabius did not think it necessary to ''combat'' Greenpeace's campaign of interference with French testing of nuclear weapons in the Pacific. The episode has clearly embarrassed France and the French. But at the same time the affair has provoked a combative spirit among segments of public opinion and among Government officials. Tonight, for example, the Government announced that President Francois Mitterrand would travel Thursday to the French nuclear testing site at Mururoa Atoll. The announcement came amid reaffirmations by the Government that the testing would continue despite protests and the uproar over the Rainbow Warrior sinking.

A former C.I.A. insurgency specialist testified to the World Court today that the agency had drafted a plan to send 1,500 armed rebels into Nicaragua and had won President Reagan's approval of it. The specialist, David Macmichael, who worked for the Central Intelligence Agency from 1981 to 1983, told the court that the agency's Latin American affairs office developed a plan in the fall of 1981 to ''destabilize the Nicaraguan Government or reduce the threat Nicaragua posed to the region.'' The Nicaraguan Government has filed a complaint charging that United States support for anti-Government rebels constitutes ''state terrorism'' and violates international law. Mr. Macmichael took the stand for 30 minutes in the second day of oral testimony in the case.

In an effort to counter Nicaraguan Government arguments before the World Court, the State Department issued a long position paper today asserting that the Nicaraguan Government has continued to supply weapons, training and advice to the guerrillas in El Salvador. The United States has refused to take part in the World Court case, so the paper has no legal force. Elliott Abrams, Assistant Secretary of State for Inter-American Affairs, said the Nicaraguan position that no weapons have been shipped from Nicaragua to the Salvadoran rebels since early 1981 ''is an outright lie.'' He asserted that there was now ''a mountain of evidence'' against Nicaragua on the issue and said even Congressional critics of United States policy toward Nicaragua accepted the evidence.

The Honduran Air Force shot down a Nicaraguan helicopter and attacked Nicaraguan positions inside Nicaragua today in the most serious border confrontation yet between the two countries, according to Honduran Government and American diplomatic officials in the Honduran capital. It appeared to be the first time Honduran forces have entered Nicaragua to attack military forces there. President Roberto Suazo Cordova of Honduras cut short a vacation to announce the Honduran attack today. The Honduran Army was mobilized and military units were moved to the border, according to Western diplomats and Honduran officials, who were interviewed by telephone in Tegucigalpa. President Suazo also recalled the Honduran Ambassador from Nicaragua.

Canada warned South Africa today that it would impose stringent sanctions against that nation unless there were changes in the policy of apartheid. The changes Ottawa is seeking include the rescinding of laws classifying South Africans by race, extending full citizenship and voting rights to blacks and releasing political prisoners. The External Affairs Minister, Joe Clark, in a major speech to the House of Commons, also announced new measures to restrict Canadian business activity in South Africa and to promote international cooperation against apartheid. They follow Canadian sanctions against South Africa announced July 6. Some of those, such as a ban on the sale of computers to South African security forces and restrictions on the import of Krugerrand gold coins, are similar to sanctions announced on Monday by President Reagan.