The Atlantic menhaden (Brevoortia tyrannus) is a silvery, highly compressed fish in the herring family, Clupeidae. A filter feeder, it lives on plankton caught in midwater. Adult fish can filter up to four gallons of water a minute; and they play an important role in clarifying ocean water. They are also a natural check to the deadly red tide.
Menhaden historically occurred in large numbers in the North Atlantic, ranging from Nova Scotia, Canada to central Florida, USA, although their presence in northern waters has diminished in the 20th Century. They swim in large schools, some reportedly up to long. As a result of their abundance they are important prey for a wide range of predators including bluefish, striped bass cod, haddock, halibut, mackerel, swordfish, and tuna.
The menhaden is also called pogy, mossbunker, bug fish, alewife, shad, greasetail, bunker, bunker fish and fat back.
The Atlantic menhaden is popular for use as live or dead bait. The fish is notorious for its rapid deterioration when caught, as well as its bony and oily makeup. As a result, they are primarily used for the production of fish meal, oil and fertilizer. It was likely the fish that Squanto taught the Pilgrims to bury alongside freshly planted seeds as fertiliser. It went on to be used for this purpose on a large scale on farmland on the Atlantic coast, though this process was stopped after it was realized that the oily fish parched the soil.
In recent years their population is considered to be sustainable coastwide, though a possibility for a localized depletion exists in the Chesapeake Bay due to a concentrated harvest. Omega Protein, a Houston, Texas-based company, has a virtual monopoly on the menhaden reduction industry in the United States. The company uses a process known as purse-seining to corral and remove from the water entire schools of menhaden, often numbering in the hundreds of thousands. Purse seining has been outlawed by every Atlantic coast state except Virginia and North Carolina. Tremendous algal blooms that starve the bay of sunlight and oxygen have been attributed to a diminished menhaden population due to the menhaden's important role as a filter feeder of algae and other phytoplankton. Significant malnutrition and disease in one of its primary predators, the striped bass, is also widespread in the Chesapeake.