Greenpeace zeros in on Norway

A blockade at sea - possibly near the port of New York - is being planned by European environmental activists and their American counterparts. Their target: Norwegian freighters and the fishermen whose products are on board for export to the United States.

Blockades on the semi-monthly shipments will continue until Norway abandons its whaling operations, says Michael Neilsen, who heads the Greenpeace organization's European lobby to save the whales. Few details have been divulged , but the protests are expected to involve a number of vessels and may begin within two to three weeks.

''Until now we have cooperated with American environmental groups working on boycotts of Norwegian fish products, and these activities will be greatly extended,'' Neilsen says. ''Last April Norway lost its contract with a major customer, the Long John Silver restaurant chain, and this was worth about $5 million. Since then McDonald's and Burger King have followed suit.''

A Norwegian official has admitted that in an important export market where antiwhaling sentiments run high a campaign of blockades and boycotts could be a serious blow to his country's vital fishing industry.

Since the International Whaling Commission met in Britain in July, Norway has become 1 of only 3 countries that object to the commission's four-year moratorium on whaling from 1986. But with Japan and the Soviet Union also refusing to accept the ban, why are the environmentalists channeling their energy into Norway?

''Our tactic is to go for the weakest country,'' Neilsen says. ''When Iceland withdrew its objection earlier this year, Norway [found] itself alone among the European countries. The Norwegians are proud of their environmental policies at home, and it is an embarrassment to be in the company of two countries with particularly poor records.''

If Norway steps into line with world opinion, Greenpeace will tackle Japan.