Atlantic bluefin tuna can sell for $20 a bite in Japanese sushi restaurants, and it's profits like these that have resulted in severe overfishing, causing tuna stocks to plunge by more than 80 percent since 1970. Conservation groups have been calling for deep cuts in tuna fishing, arguing that the tuna is being fished into extinction. However, at last year’s meeting of the International Commission for the Conservation of Atlantic Tuna, the organization set a 2011 quota of 12,900 tons, down just 600 tons from 2010. Conservationists say not enough is being done to protect the bluefin tuna, and activists have become more involved in the issue. In June 2010, the Sea Shepherd Conservation Society launched “Operation Blue Rage” and began freeing tuna from fishing nets. That same month, a Greenpeace activist was hospitalized after a fisherman threw a grappling hook into his leg as he attempted to free the endangered tuna.