The answer, or so we thought at the time, was to ban the encirclement method of tuna fishing. It was one of the most visible and effective victories in the history of environmental activism. But this is not the truth. It only means that no dolphins were encircled. The good news is, an observer is on board each ship in the eastern Pacific, and dolphin deaths have indeed declined there.
Ships get by with verbal reports to dockside observers.
Bottom line, no matter what fishery it comes from, when you pull a can of tuna off the grocery shelf, you really have no idea whether a dolphin was killed or not. Earth Island Institute would prefer that you did not realize this. It means we made a good start. Thankfully, these nations and the U.S. signed a voluntary initiative to reduce dolphin deaths. In 1992, in La Jolla, California, the fishing countries of the eastern Pacific negotiated a voluntary schedule for reducing dolphin deaths by three fold over seven years - from 19,500 to less than 5,000 by 1999.