Originally posted on December 11, 2009.
In our chapter, Public Goods and the Tragedy of the Commons, we discussed the 75% decline in the catch of southern bluefish tuna, which is highly prized as sushi. 60 Minutes has a great episode on this issue which covers the fascinating Tsukiji fish market in Tokyo, the biggest wholesale fish and seafood market in the world, the Mediterranean fishermen who are losing their livelihood as fish stocks decline, the industrialization of fishing (including tuna ranches!) and finally the decline of the tuna stock.
The whole video is fascinating but if you want to shorten it I suggest covering the first 4 minutes on the Tsukiji fish market then jumping to around the 8 minute mark when the purse seiners are discussed.
An interesting puzzle is that tuna is relatively inexpensive. Ask students whether this can be reconciled with an impending collapse of the tuna stock. After all, isn’t a low price a sign of plentiful supply? The answer points directly to the tragedy of the commons – the low price is possible because the purse seiners are scooping up enormous quantities of tuna which pushes today’s price down but too few fish are left to breed so future stocks are imperiled. An entrepreneur who owned the stock of tuna–like Frank Purdue owns his chickens–would not do this but tuna are not owned until they are caught. In other words, the current tuna boom is like “eating the capital stock,” you get a big party today but a tragedy tomorrow.
FYI, the tragedy of the commons is driving many other fish stocks into collapse.