In the 1980′s, fishermen trawling for tuna killed tens of thousands of dolphins each year, scooping them up as “bycatch” in their nets. A public backlash spurred development of a “dolphin safe” fishing method — which, while great for dolphins, turns out to be a catastrophe for sharks, sea turtles, mahi-mahi, and other sea creatures, many of them endangered. Dolphin-safe fishing is also a less ecologically sustainable way to harvest tuna stocks. The Southern Fried Science blog has the grisly details, showing that eco-reform, like everything else, is beholden to the law of unintended consequences. [%comments]
Unintended Consequences in Tuna Fishing
TAGS: unintended consequences
and 
. You can also watch it on 
This seems like a fair argument in the defense of not only dolphins but also any other sea creature. The world, as it is, is suffering from a condition called the “tragedy of the commons” which basically means we are taking to much from places that don’t belong to use, but belong to everyone. This is tragedy that in time will affect everyone, and most definitely have an impact on the economy. If too much tuna is fished one year, then they wont be able to reproduce enough to satisfy everyone’s needs. This usually happens when people start getting greedy, and try to take more than the competition. In a way it might seem as if these new fishing methods, which prevent the dolphins of being caught, but have the opportunity cost of catching less tuna, might be better, than just catching as much as you can of everything. This would cause the the price of the tuna to go up, but it would prevent a tragedy of the commons, and if a tragedy of the commons were to occur, then wouldn’t this as well make the price of the tuna go up? I mean, there is less tuna, giving the people who sell tuna scarcity power, basically regulating the price at what they feel is correct.
On the other hand, we have the problem of other sea creatures in extinction getting caught as well, in this new way of fishing. This is also a problem because, first of all no animal should be in extinction, no matter how useless they might be, and second of all if one sea creature goes extinct, then it will affect the way that the whole marine cycle works, because you are taking out a component of it. The best thing to do in this case to devise a way in which tuna, and only tuna are caught. Maybe by using something only tuna is attracted to as bait, or isolating the tuna, and putting them on breading grounds (which is done with other types of fishes like salmon).
In conclusion the opportunity cost regular tuna fishing is also fishing dolphins, which are in extinction, and creating a tragedy of the commons. In the other hand we can use the dolphin-free fishing method, but make sea creatures go extinct disrupting the marine life cycle.
Isn’t the lesson that not accounting adequately for externalities creates a backlash that creates distortions?
It’s not that the dolphin free initiative was at the behest of eco freaks that valued dolphins above the other species you mentioned. Rather, the outcry was against the impact and waste of the existing harvesting techniques. “Dolphins” in a way was simply a metaphor for the unaccounted environmental impact — costs imposed on us all that were not borne by the harvesters.
I’m not sure that your argument is that any attempt to address externalities will result in absurd distortions and area waste of time? Seems a tad cynical. Note that the comments seem to have stirred up the usual cynical anti eco freak humbuggery.
Mahi-Mahi are too valuable to be considered by-catch.
Agh the worst part about it is I hate dolphins!
Are there any dolphin-lethal brands I can buy?
Also @11, not unless they’re separated, processed differently, and sold as Mahi Mahi.
The problem is tuna purse seine fishing. It isn’t sustainable, be sharks, turtles, dolphins, and not even the tuna. Take a pick? I say, industrial tuna purse seiners have got to go…and replaced by the old pole method. The problem is that you have the industry, with all their infrastructure and political and economic power, pushing to keep the status quo, organized in Tuna Commissions all over the globe, where they are represented IN the local governments. The sad thing, is that this doesn’t seem like it will stop, precisely because of this political arrangement, until of course the tuna are depleted and the industry collapses, dragging the turtles, sharks and dolphins to extinction. This has already happened to several species of tuna, and its happening to the yellow fin tuna in the Eastern Pacific too.
Dolphins: cute, great personality, very photogenic.
Other species: not so much.
Dolphins: Win!