Dolphin safe tuna

One of the most reliable ways of locating tuna stocks is by following dolphins. Once you find dolphins feeding on the fish, you set your nets around and catch them. Of course, this method will sometimes lead to you catching dolphins as well. In eighteen years of dolphin set tuna fishing in the United States, 18 dolphins were recorded as caught, along with 34 tonnes of sharks and rays and 295 tons of other fish. Such by-catch is virtually always discarded. In an equivalent period of dolphin safe fishing (where electronic Fish Aggregation Devices are used instead), no dolphins were caught, but 237 tonnes of sharks and rays were, along with 15,500 tonnes of other fish. Again, this was discarded.

Dolphin safe fishing is also disproportionately likely to catch immature tuna, which have not yet reached their full size and which have contributed very little to reproducing the species, since tuna generally take a long time to reach sexual maturity.

This only makes sense if you strongly privilege dolphins over other forms of marine life. Either because:

  1. You think dolphins themselves are bearers of rights
  2. People have much stronger preferences regarding dolphin treatment than that of other elements of marine ecosystems, and those preferences determine what is moral.

Admittedly, each of these is a viable moral position consistent with the ways in which we generally view what kinds of things can bear rights. That said, the trend in ecology is towards recognizing the importance of ecosystem integrity. From this perspective, setting nets around dolphin pods is probably the greenest way of catching tuna. This is especially true since it is possible to design nets that dolphins virtually always escape, but tuna do not.

Of course, now consumers know that to be eco-friendly, they are meant to buy the dolphin safe tuna. Confident in the belief that the problem has been dealt with, not enough people realize that we have probably made things worse.

Author: Milan

In the spring of 2005, I graduated from the University of British Columbia with a degree in International Relations and a general focus in the area of environmental politics. In the fall of 2005, I began reading for an M.Phil in IR at Wadham College, Oxford. Outside school, I am very interested in photography, writing, and the outdoors. I am writing this blog to keep in touch with friends and family around the world, provide a more personal view of graduate student life in Oxford, and pass on some lessons I've learned here.

7 thoughts on “Dolphin safe tuna”

  1. There are tons of websites of varying levels of credibility that speak on this issue. I got the information above from a presentation I gave in my global environmental politics class in fourth year with Peter Dauvergne.

    I dug it up because we were talking about the WTO dolphin case during my international law seminar today.

  2. According to this Economist article: “Tangled nets.” Oct 2nd 2003

    “Mario Aguilar, of Mexico’s National Commission of Fisheries, stresses that chasing dolphins is the greenest way to fish tuna. Greenpeace agrees, as does the World Wildlife Fund.”

    I am not sure how to square that with how the Greenpeace website seems to have an ongoing campaign against easing restrictions on fishing tuna by following dolphins. Perhaps they recanted, since the article was printed.

  3. Remember when we ate blue fin tuna at hapa izakaya? Deliciously endangered…

  4. Ashley,

    When your bosses see that comment they will cry, then probably fire you.

    Poor Thunnus maccoyii. They have a huge skeleton in the Natural History Museum in Oxford, for anyone nearby who wants to get a sense of their sheer scale. (Up to 2.5m long and 400kg)

  5. Basically, the problem isn’t tuna fishing. The problem is Saner fishing. When my father was a salmon fisherman, he had lines with bait on them. Not anymore, now everyone trails nets of various sizes. The really huge nets which circle around and choke the sea are Saners.

    No one should eat food that comes out of Saners nets. They are the wall mart of the ocean – the boats are so huge that no real people own them, and people work on them for wages. This is not the life of a fisherman. Also, the by-catch is insane and all thrown out.

    They ought simply be made illeagle. We act as if the fishing problem is so unsolvable – it’s not! It’s simple, we just need to restrict the legal methods of catching fish. If they were restricted to small nets, and lines, and licenses were restricted, the price of fish would go up, the number of fishermen who can make a living would not neccesarily plummet.

    The real villain here is capital and technology.

  6. While purse seiners may be damaging, they are a lot better than bottom trawling.

    That catches everything in the path of the net and smashes anything unlucky enough to be sitting on the ocean floor.

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