FROM legislation in the US Congress to a stricter code of fishing ethics agreed upon in Rome, new efforts are emerging to deal with the dramatic decline in fisheries around the world.
In just the past week:
* The Food and Agriculture Organization (FAO), a United Nations agency with 174 member countries, approved a new ''code of conduct'' in Rome, calling for selective fishing techniques to replace mass netting that kills millions of fish thrown away as trash.
* Delegates to another UN-sponsored conference in Washington this week and next are looking for ways to protect marine areas from land-based pollution, which is damaging to fish habitat.
* The United States Congress passed a package of conservation bills designed to protect fisheries in US and international waters.
* The Clinton administration and a group of key lawmakers announced a plan to finance the rescue of dwindling salmon in the Columbia River Basin. The bipartisan nature of these efforts stands in sharp contrast to the ideological battle characterizing most other environmental issues on Capitol Hill these days.
There is much evidence that fisheries are in trouble.
The FAO estimates that some 70 percent of global fish stocks are depleted or at least over-fished. ''The ocean's most valuable commercial species are fished to capacity,'' the FAO states.
According to the American Oceans Campaign, an environmental group based in Santa Monica, Calif., some 40 percent of US fish species are over-fished, and many of the most economically valuable fish (such as haddock and bluefin tuna) ''are threatened with commercial extinction.''
In Alaska, what used to be a 120-day halibut fishing season has been cut to one day a year. And in Danvers, Mass., this week, the New England Fishery Management Council met to figure out how to bring back depleted stocks of cod, haddock, and yellowtail flounder in the Atlantic Ocean.
The fundamental problem is more people fishing with more sophisticated equipment.
The world's marine catch increased more than fourfold during the postwar period as the global fishing fleet doubled to more than 3 million vessels. Armed with radar and sonar equipment, trawlers as long as a football field can pull in 30 tons of fish in one net. And while roughly 85 million tons of fish are harvested every year around the world, 27 million tons are tossed overboard as unwanted ''bycatch.''
More fish eaters is another part of the problem, especially in developing countries where fish protein is a relatively large part of people's diets.
''At the moment, population growth is fueling about two-thirds of the current growth in demand for fish,'' says Robert Engleman, co-author of a recent report on the decline of fisheries by Population Action International, a research and advocacy group.
LEGISLATION approved in Congress this week and headed for President Clinton's signature includes several fisheries conservation measures.
It prohibits the US from entering any international agreement with countries that violate the UN ban on drift nets (plastic nets that are several miles long and kill millions of unwanted fish). Another measure provides for the seizure and confiscation of foreign vessels failing to follow sound conservation practices inside the 200-mile US territorial limit.
The House also recently reauthorized the Magnuson Act (a comprehensive fisheries conservation law first passed in 1976) through the year 2000. New provisions are designed to reduce the number of bycatch killed and protect fish habitat. The bill also more strictly regulates regional fishery management councils, which set catch limits.
On Monday, Vice President Al Gore, Sen. Mark Hatfield (R) of Oregon, and several Democratic senators from the West announced a six-year agreement on funding of federal efforts to recover salmon in the Pacific Northwest. This provides that the Bonneville Power Administration (BPA), which markets electricity from eight major dams in the Columbia River Basin, will spend $435 million a year on salmon recovery efforts.