There is absolutely nothing wrong with eating bluefin tuna.
Bluefin is a delicacy, not usually eaten as steaks. It is usually three small slices, certainly no more than five or six, on a plate containing three or four species of fish.
In the controversies surrounding fishery management and questions of species abundance in the US and Europe, environmental organizations may tend to overstate the issues, and for very good reason: Environmental organizations are essentially lobbyists and mostly depend on public donations for their livelihood. Therefore, they tend to overstate in order to attract the attention of the public to a given issue. And that is precisely how public opinion has been shaped on the issue of bluefin.
Anyone who reads the news knows that these days NOAA is not considered a compliant partner of US fishermen. NOAA’s decision to not place Atlantic bluefin under protection of the Endangered Species Act at the end of May 2011, was not a capitulation to the bluefin fishermen, but an historic decision based upon exhaustive study undertaken over 12 months and involving US and European scientists and fishery management specialists both inside and outside of government. Some of the best minds in bluefin science had input into this exhaustive process. There is no doubt that if NOAA had any way of validating the probability of extinction or even the threat of extinction, they would have listed the bluefin under ESA. The simple fact is that there is no creditable pelagic scientist who will sign their name to a statement saying that Atlantic bluefin is, 1/ endangered with extinction, 2/ threatened with extinction or, 3/ near [or “on the edge of..”] extinction.
As to the issue of commerce driving the bluefin to extinction, we can thank the media for this misunderstanding. There are no US bluefin fishermen who have Mercedes parked in front of their homes. Practically every article written on bluefin never fails to mention that bluefin sells in Tokyo for upwards of $150,000 “for one fish”. It is amazing to me that journalists have never even bothered to check on this. Auction data from Tsukiji Market for bluefin is available every day online. US bluefin fishermen receive approximately $4-8/lb for their fish, less than they would get if they fished for scallops. The US bluefin fishery is a small, artisanal fishery in which the fish are caught sustainably using hand techniques. The Pew has recently validated this statement. No industrialized fishing methods are allowed. Each vessel is a sole proprietorship, owned by its captain. The US bluefin artisanal fishery is the most highly regulated bluefin fishery in the world. The limit per day in season is three fish and the minimum size must be 73”. A fisherman would be very lucky to catch three fish in one day. It is true, however, that once every year or so, usually in Dec or Jan, an Asian restauranteur dramatically bids up the price of one bluefin at Tsukiji Market as a publicity stunt and this is what finds its way into the media.