REPRESENTATIVES OF THE tuna fleet have been splashing about in Washington trying to persuade Congress, the Commerce Department, environmentalists and other that "utter economic disaster" is coming if the industry is not allowed to go fishing in its own style. The source of this supposed doom is the 1972 Marine Mammal Protection Act. Among other measures, it requires that tuna fishermen reduce the killing of porpoises, those air-breathing mammals of the sea that are used by the fleet to find the deep-swimming tuna. As traveling companions, the porpoises are often caught in the tuna nets.Over the years, several million of these intelligent and fun-loving creatures are said to have died (by drowning or shock) as the tuna were trapped.

Rather than accept the decision of Congress, as well as several courts, the tuna fishermen have decided to try to change the law. Failing that, they are threatening to transfer their vessels to foreign flags to get away from the law altogether.

Confronted by forces that agree with the 1976 ruling of Judge Charles R. Richey - that "porpoises and other marine mammals must be protected from the harmful and possibly irreversible effects of man's activities" - the industry has unwisely gambled that resistance is better than adjustment. It has shown little taste for using or developing new methods and technology that would reduce the porpoise slaughter. Recently, the Commerce Department, backed by Juanita Kreps, proposed a new quota of 59,050 porpoises as the limit for this year. The letter of the law actually calls for a kill-rate approaching zero. Environmentalists, who have won several court cases involving porpoises and the 1972 law, would like the 59,050 figure to be lower, but in a healthy spirit of compromise, they are accepting it. Not so the tuna men.

How much support the industry can muster remains to be seen. Hearings have been held in the House and are planned in a few days for the Senate. In our view, the tuna men have been receiving fair treatment. It is less the 1972 law that is bedeviling the industry than its own refusal to accept reasonable restraints. As for Mrs. Kreps her involvement in this dispute is welcomed. In the past, the Commerce Department's indecisiveness in enforcing the law has been part of the problem.