Overfishing—taking fish and other sea creatures from the ocean
faster than they can reproduce—has caused more change to the
world’s oceans than any other single factor so far. From fish to
whales, fishing has depleted many populations of ocean animals.
Some have collapsed to very low numbers. Some are no longer
commercially viable. “How much can we take? and “How much should
we leave?” Fishery management tries to limit human
activities—where, when, and how people can fish, and what they
can take. That’s the idea anyway. It’s about a century old, but
few places have the budgets, personnel, or rule of law to really
limit fishing. Mainly, it hasn’t worked. The U.S., Australia,
New Zealand, and the Falkland Islands are among the few
countries where fishery management is generally organized and
implemented well enough to prevent depletion or let overfished
species recover. This has led many conservationists to say, if
we can’t manage fishing, maybe the best thing we can do is ban
fishing in areas large enough to l