Flavor and health benefits lure people to seafood. Consumer demand, however, can lead to a depletion of the ocean's resources. While markets today offer a variety of sustainable fish choices, they can be expensive. It's simple economics: High demand plus low supply yield higher prices. Buying sustainable seafood increases the odds that your favorite fish will be available and affordable in the future.
What does "sustainable" mean? Monterey Bay Aquarium spokesman Ken Peterson explains, "Sustainable seafood comes from sources, whether fished or farmed, that can exist into the long term without jeopardizing the health of the fish population or the integrity of the surrounding ecosystem." Key factors that determine sustainability are population, percentage of by-catch, and impact on the environment.
Harvesting quantities of fish that leave too few to reproduce renders populations unsustainable. Examples of fishery collapse include Atlantic cod and wild Atlantic salmon. The latter is considered commercially extinct―only farmed Atlantic salmon appears in markets. Overfishing proves especially troublesome for slow-growing fish, such as Pacific rockfish and Patagonian toothfish (Chilean sea bass), both of which reach spawning age at about 10 years. Some species of orange roughy need 20 years to mature. If overfished, stocks can take decades to recover.
By-catch occurs when such nontargeted ocean-dwellers as sea turtles, albatrosses, and dolphins are caught with the harvest. Trawling for wild (not farmed) shrimp brings up an inherently high degree of by-catch (up to 10 pounds per pound of shrimp). Turtle- release nets and fish-excluder devices used by U.S. trawlers and the availability of trap-caught shrimp help keep this number from escalating even higher. Farmed seafood such as catfish, striped bass, and shellfish has little by-catch due to aquaculture methods.
Habitat destruction happens when manufacturing waste pollutes streams, rivers, and oceans. Dams are especially problematic for spawning fish that attempt to return to their natal waters. Harmful harvesting methods have the potential to sweep vast sections of ocean floor barren of life, wreaking environmental devastation.
The bottom line is that consumers make a difference. If shoppers are selective about fish, reduced demand for jeopardized species will force fishers to turn to more abundant seafood. And the old adage "there's always more fish in the sea" would once again ring true.
Downloadable seafood cards listing safe seafood choices.
Seafood Watch cards from the Monterey Bay Aquarium.