How Many Fish in the Sea?

How many fish in the sea? The answer is not as many as the commercial fishing industry would like you to believe. You can access a blow up of this map here. The map of the North Atlantic on the left shows the biomass in tons of popular food fish per square kilometer in 1900. The one on the right shows the same data for 2000. Clearly overfishing is destroying the fish stock of our favorite food fish like cod and haddock. The map is based on a statistical study called "Hundred-year Decline in North Atlantic Predatory Fishes." So we've screwed up the ocean as a food source, and there is very little evidence that things are going to change. We could all start eating sand lance like the Humpbacked Whales, but somehow I'm not expecting that on the Legal Seafood menu any time soon.

Interestingly, at least one article I've read recently from an environmental organization promotes fish farming. As you may know, most environmental groups have been down on aquaculture because poor practices can pollute the sea, introduce disease to wild populations, and weaken wild fish population with genes from escaped domestic stock. Obscured in these strong arguments are the pluses of fish farming. Fish fed on grain based pellets require less food to produce a pound of fish compared to chickens, pigs, or beef. Industrial production of livestock also produces more methane than similar sized fish operations. Unfortunately, as you can see by checking out the fish counter at any supermarket, most fish farms are in Asia where environmental regulations are more lax than in North America or Europe, but the article notes that China, a major producer, is set to upgrade its regulations regarding aquaculture. We'll have to wait and see.

The collapse of fishing stocks is another example of the Tragedy of the Commons, a basic environmental principle that proves that some kinds of free markets need government regulation to actually work. Here's the classic example. Imagine that Boston Common has been turned back to its original purpose of grazing land for people in the town. Imagine that 100 sheep can graze there and become fat and wooly. Imagine further that 10 shepherds have 10 sheep each there. One day a shepherd figures out that adding one more sheep to his flock will make him richer than the other 9 farmers. All 101 sheep will be a little less fat and wooly, but our capitalist shepherd will have 10% more sheep to sell less the tiny loss that is spread among all the sheep. The rational individual decision for all the other shepherds who have families to feed is to add sheep as well. Any shepherd who doesn't do so accepts all the losses in fat and wool that come to his sheep without the benefit of additional skinnier less wooly sheep to sell. Ultimately, the Common gets so overgrazed that no one can graze sheep there. The solution is for the ten shepherds to get together and regulate the number of sheep on the Common.  Unfortunately, the North Atlantic is vast, and the number of fisherman large and multinational so it has been difficult for the players to see that while it is always beneficial for you to pull one more cod out of the ocean; it is not good for the commons long term. Hence government regulation of fisheries is fought rather than accepted by the fishermen. Trevor Corson's 2005 The Secret Life of Lobsters tells how Maine lobstermen in a much smaller commons began self-regulation several generations ago. All in all, for New Englanders the travails of the fishing industry is of major importance both for our pocketbooks and our dinner plates.