Next time you're in the mood for fish, chances are you'll buy some tuna steaks, or maybe salmon fillet rather than a fish called menhaden. Menhaden aren't very tasty; they're small, bony, and oily. What's more, you won't find menhaden for sale at the fish counter. Nevertheless, they are the single most harvested fish in Atlantic and Gulf waters.

Though they don't make tasty fillets, menhaden are an important food source in other ways. Members of the herring family, protein-rich menhaden are ground up and used as feed for chickens, pigs, and cattle. They're also a primary food source for many larger fish such as bass, cod, and tuna. So whenever you bite into a burger, you might also be indirectly consuming menhaden.

Menhaden were once so populous that from a bird's eye view schools of the tiny fish resembled small islands. But in recent years over-fishing in bays and estuaries along the Atlantic and Gulf coasts has drastically reduced their numbers. Besides helping to cleanse the water of damaging algae, menhaden are a staple of the coastal marine food chain. Their disappearance therefore negatively affects many species of fish and birds, as well as the food chain in general.

Nevertheless, menhaden fisheries continue to harvest the species without regard for shrinking numbers. This will have little impact on the availability of beefsteak, since soybeans are an alternative to menhaden as a source of animal feed. But as menhaden numbers continue to drop, it may become more difficult to get tuna steak on demand. As menhaden go, so goes the coastal food chain, an interconnectedness affecting countless marine species.