The super-fast and warm-blooded bluefin tuna competes with fisheries off the U.S. Atlantic coast for menhaden, its preferred prey.
Atlantic bluefin tuna are extremely fast-swimming migratory fish found throughout the Atlantic Ocean. Prized as one of the most valuable fish in the sea, bluefin tuna have been heavily overfished. Bluefin tuna off the east coast of the U.S. feed primarily on menhaden in the winter, which makes up to 96 percent of their diet. When menhaden disperse each spring, bluefin tuna migrate north in search of herring and other prey.
Atlantic menhaden is a bony, oily fish considered inedible to most humans. However, its high level of omega-3 fatty acids make it a favorite prey item for many fish higher up the food chain, including striped bass and bluefin tuna. Menhaden also serve other important ecological roles by feeding on microscopic algae which can otherwise grow out of control, particularly in polluted coastal waters. They live in near-shore waters from central Florida to Nova Scotia, Canada.
Bluefin tuna face multiple threats and have been severely overfished, losing 80 percent of their population since 1975. Bluefin tuna are further stressed by fisheries targeting menhaden, which is their primary food source for a large portion of the year. The menhaden fishery is the second largest in the United States and this extreme competition for resources can only make it harder for bluefin tuna to recover.