Menhaden are small fish that play a gigantic role in the Atlantic marine ecosystem—and they're in trouble. Similar to the delta smelt of the San Francisco bay, these unassuming fish are so vital to the bay's ecosystem that last year, the federal government stepped in to enforce Endangered Species Act laws that stopped the delivery of fresh water to agricultural lands in the central valley. Menhaden is similar to the delta smelt in both size and vitality to the larger ecosystem as a species indicator.
Menhaden spawn and grow in the ocean. Unlike some fish that spend part of their lives in freshwater and salt water, its entire life is spent in the Atlantic. It feeds on microscopic plankton, tiny animals most fish and marine birds cannot eat, and turns that into a digestible resource. This makes menhaden a fish that other fish and birds of prey readily feed on. Thus, it's a vital part of the Atlantic marine food chain.
Without menhaden, the Atlantic marine ecosystem would quite simply collapse. The alarming reality is that signs of this collapse — as evident in the health and population of menhaden — are becoming ominous.
Read the complete piece from Greenpeace.