Sainsbury’s, the large U.K. supermarket chain, recently adopted a red/yellow/green approach to sourcing fish supplies. If it judges a particular fish stock to be in “red” condition, or overfished and at risk, Sainsbury’s will not purchase that species from that source.

This places Sainsbury’s one step ahead of the international certification group, the Marine Stewardship Council (MSC), which labels as “sustainable” stocks whose managers have applied for certification and passed the panel’s rigorous inspection. Some of these certified stocks include, in the U.S., Alaskan wild salmon, two Alaska pollock fisheries, North Pacific halibut and sablefish, Pacific longline freezer cod, as well as more than a dozen other stocks from different countries.

Another 20 or so species are under review for certification, several of them U.S. species. The MSC, formed in 1996 by cooperation between the giant Dutch-British transnational corporation, Unilever, and the former World Wildlife Fund — now the World Wide Fund for Nature. The Council has its critics, but it represented the first major effort to certify sustainability and give consumers a benchmark for seafood choices.

A few smaller organizations publish their own “don’t buy” lists for consumers, including the Monterey Bay Aquarium and the New England Aquarium. These, too, have their critics. Several years ago, Monterey Bay listed Maine lobster as endangered until a traveling Maine lobster harvester stopped in to explain the aquarium’s mistake. The U.S.-based Chef’s Collaborative organized a boycott of swordfish, asking chefs to stop serving the fish because it was endangered. Some chefs did their homework first and discovered that swordfish sourced from U.S. fishermen were not harvested in an unsustainable fashion and were of the proper size required under the international agreement governing swordfishing.

Some restaurateurs undoubtedly just ignored the boycott because swordfish is a good-selling menu item. Some who were listed as joining the “Give swordfish a break” movement objected, saying they had not signed on. Later, the groups behind the movement took credit for the rebuilding of swordfish stocks, although the U.S.-based effort, even if it had been much larger than a couple of hundred restaurants nationwide, would have had a minimal effect on the harvesting and sale of a highly migratory species fished by many countries and sold worldwide.

Busy consumers who don’t have time to do their own investigations to determine which fisheries are endangered or sustainable, may rely on such lists or certifications to help them make informed decisions. Certainly, if more and more consumers are becoming concerned about the source of their food, as news stories increasingly tell us, these lists are better than nothing when they’re not too far wrong.

The Sainsbury’s approach is more democratic and inclusive in some ways than the MSC’s “green” labeling program, which requires an investment of money on the part of the fishery applying for the five-year certification, and another investment every time re-certification is needed.

Some critics say smaller fisheries are left out of the MSC process because they can’t afford it. Others say the interests of big businesses, such as Unilever, are in opposition to the democratic goals of the MSC, even though the panel is independent of Unilever now. These days, all efforts are politically suspect by one side or the other, or as in this case, both.

But consumers would be well served by a system such as Sainsbury’s — as long as they could have confidence in the process by which the red, yellow and green lights were assigned. The National Fisheries Institute will discuss the New England Aquarium’s Choice Catch program and the Sainsbury approach at an upcoming meeting. Perhaps they will help retailers find a simple method all can agree on to inform concerned consumers about “sustainable” choices when buying seafood harvested from wild stocks. Meanwhile, if seafood consumers want to make a New Year’s resolution to help endangered stocks, they can do their own research. Anyone can go on the United Nations’ Food and Agricultural Organization’s website and find their worldwide assessments of fish stocks. Then for domestic stocks, there’s the National Marine Fisheries Service website. These sites provide broad-scale, generic information, but they’re a starting point for consumers who wish to become well informed and they’re a benchmark against which to measure the “don’t buy” lists.