A catch-22: commercial fishing and the evolution of fish

Atlantic cod

Maritime Aquarium at Norwalk

Few things illustrate the concept of sustainability as clearly as overfishing. When fish are harvested from an area more quickly than they reproduce, the population necessarily shrinks, and the catch shrink along with it.

But fish may actually be evolving in response to the pressure of fishing, reaching reproductive maturity more quickly. That adaptation comes at a cost, however. Fish that spawn earlier might be less fertile, grow less after they’ve reached sexual maturity, and could become more susceptible to other non-human causes of death. Previous studies have shown that those trade-offs could exacerbate the economic and ecological problem of collapsing fisheries.

A new study this week suggests that these genetic changes could actually be economically beneficial to fisheries—but only if they’re managed sustainably.