Menhaden, also known as mossbunker and bunker and "the most important fish in the sea", are forage fish of the genera Brevoortia and Ethmidium, two genera of marine fish in the order Clupeiformes. Menhaden is a blend of poghaden and an Algonquian word akin to Narragansett munnawhatteaûg, derived from munnohquohteau, referring to their use of the fish as fertilizer. It is generally thought that Pilgrims were advised by Tisquantum to plant menhaden with their crops.

Forage fish, also called prey fish or bait fish, are small pelagic fish that feed on plankton and other tiny organisms. They are preyed on by larger predators, including larger fish, seabirds and marine mammals. Typical ocean forage fish feed near the base of the food chain on plankton, often by filter feeding. They include particularly fishes of the order Clupeiformes, but also other small fish, including halfbeaks, silversides, smelt such as capelin and goldband fusiliers.