In many parts of the world, consumer pressure has led to the labeling and sale of dolphin safe tuna, which is tuna caught without harming or killing dolphins. These concerns arose in the 1980s, when public awareness campaigns by organizations like Greenpeace and the Earth Island Institute alerted consumers to the fact that thousands of dolphins were dying along with tuna every year. The thought of these lovable marine mammals being harvested along with tuna was revolting to many consumers, who started to boycott companies that harvested tuna in an unsafe way. The Earth Island Institute began offering a certification program for dolphin safe tuna, and numerous governments also began to create dolphin safe tuna laws and labels so that consumers could make informed choices about their purchases.
Dolphins are often caught up in the nets used for tuna because of the way in which tuna is harvested. Large circular nets are cast down in a very large area of ocean and then slowly contracted, picking up all of the marine life in the region. Dolphins can be caught in the nets and drowned, or experience severe trauma from the fishing nets. The contents of the nets are dumped on board the fishing ship, and any unwanted species, including dolphins, are tossed back into the water, whether or not they are dead. Drift nets, gill nets, and purse seines are all potentially deadly for dolphins.
There are ways to capture tuna without harming dolphins and other fish in the sea. After heavy consumer boycotting led to demands for dolphin safe tuna, many companies started exploring these humane options. In the United States, all tuna canneries tried to voluntarily obtain and sell dolphin safe tuna, and in 1991, the United States government enacted standards through the Department of Commerce which dictated the requirements for dolphin safe tuna labeling. In 1997, these requirements were controversially relaxed in response to industry pressure, leading to a rise in independent certifications by organizations like the Earth Island Institute.
Most government standards for dolphin safe tuna dictate that no dolphins can be killed or seriously injured in the process of fishing for tuna. Dolphins may be caught in nets, as long as they are not injured. Marine biologists argue that the trauma of being caught up in fishing nets constitutes an injury, but federal governments apparently do not agree. Independent certifications are more rigorous.
The Earth Island Institute offers a dolphin safe tuna label to companies which do not use drift nets, kill or injure dolphins in their nets, or harass dolphins during a fishing trip. Furthermore, dolphin safe and dolphin deadly tuna cannot be mixed in boat wells, and ships over 400 gross tons must submit to being accompanied by an independent observer.