Biomass: According to the 2010 benchmark stock assessment and the 2012 stock assessment update, overfishing is occurring, but it is unclear whether the stock is overfished. Sensitivity runs of the model in the 2012 assessment update produced conflicting results regarding the overfished status. Since the 1990s, generally low recruitment and declining population fecundity (number of mature eggs) have occurred.
Biological Reference Points: Established November 2011. The Atlantic State Marine Fisheries Commission adopted new threshold and target fishing mortality rates based upon Maximum Spawning Potential (MSP). The new threshold and target levels equates to a MSP of 15% and 30%, respectively. With these newly adopted fishing mortality reference points, the fishing mortality threshold is set at F=1.34 and the target is set at F=0.62.
Overfishing: Based on the revised 2009 Atlantic menhaden stock assessment and the new fishing mortality threshold, overfishing is occurring. Fishing mortality in 2011 (the latest year in the assessment) is estimated at 4.5.
Overfished: It is unknown whether the stock is overfished. Sensitivity runs of the model in the 2012 assessment update produced conflicting results regarding the overfished status.
Fishing and habitat: Atlantic menhaden are primarily caught via purse seine in the commercial fishery. Omega Protein is the only commercial reduction fishery along the Atlantic Coast. The bait fishery for menhaden has become increasingly important from North Carolina to New England. The purse seine is highly effective and has little to no effect on habitat. Cast nets are also used for limited bait catch in the recreational sector.
By-catch: The menhaden fishery is one the of most selective, and effective fisheries, with a small by-catch. Atlantic croaker is the principal species caught as by-catch and is considered insignificant.
Aquaculture: Menhaden aquaculture is nonexistent, but menhaden products are used in aquaculture of other fish. Reduction of menhaden yields three products: fish meal, fish oil, and fish solubles. The fish aquaculture industry depends heavily on fish meal to improve feed efficiency and produce maximum growth rates. Crude fish oil is used in foreign aquaculture, while refined fish oils are used as a nutrition supplement for people. Fish solubles are used to fortify fish meal and increase nutrition in the aquaculture industry.
Science and Management
The Atlantic menhaden fishery is managed by the Atlantic States Marine Fisheries Commission (ASMFC), which tracks and regulates harvest under Amendment 2 to the Interstate Fishery Management Plan for Atlantic menhaden. In October 2006, ASMFC limited menhaden harvest for the reduction fishery in the Chesapeake Bay to a five-year annual cap of 109,020 metric tons. This cap was in place 2006-12. Amendment 2 was approved in 2012; it establishes a 170,800-metric ton total allowable catch for the entire Atlantic coast that will be in place from 2013 until the completion of the next benchmark stock assessment (scheduled for peer review in December 2014). The total allowable catch allocates a specific catch limit to each state. Maryland is allocated 1.37% of the total coastwide catch; the Potomac River Fisheries Commission is allocated 0.62%; Virginia is allocated 85.32%. States are required to close their fisheries when they reach their specific catch allowance.
During the 2010 Atlantic menhaden benchmark stock assessment, the Peer Review Panel noted that menhaden population abundance had declined steadily and recruitment had been low since the last peak observed in the early 1980s. Over the period of known exploitation, menhaden recruitment appears to be independent of fishing mortality and spawning stock biomass, indicating environmental factors may be the defining factor in the production of good year classes. If menhaden recruitment is largely environmentally driven, adoption of the new reference points (MSP approach) may not result in better recruitment. However, there is a possibility that the stock may be able to take greater advantage of favorable environmental conditions if a larger percentage of spawning adults remain in the population.
The NOAA Chesapeake Bay Office provides objective science to support regional management of Atlantic menhaden, and has funded a variety of research projects to determine menhaden abundance in the Bay; estimate menhaden removal by predation; determine the flux of menhaden between the estuarine and coastal systems; and understand larval recruitment dynamics in the Chesapeake Bay and waters of the mid-Atlantic. The Center for Independent Experts reviewed the NOAA Chesapeake Bay Office’s menhaden research program and submitted reports authored by experts from Australia, Canada, and Great Britain.
Life History and Habitat
Life history, including information on habitat, growth, feeding, and reproduction of a species, is important because it affects how a fishery is managed.
Geographic range: The Atlantic menhaden is found in coastal and estuarine waters from Nova Scotia to northern Florida.
Habitat: Menhaden are common in all salinities of the Chesapeake Bay, swimming in large schools close to the water's surface during the spring, summer, and fall. Throughout the spring, the schools stratify by size and age along the coast so that by the summer, younger and smaller fish are found in the Chesapeake Bay and south while the older, larger fish are distributed to the north.
Life Span: Can live up to 10 to 12 years.
Food: Menhaden feed on both phytoplankton and zooplankton. In their well-nourished state, these filter-feeding fish are referred to as fatbacks or bunkers.
Growth Rate: Larvae of 10-34 mm TL (0.4-1.3 in) appear in the Chesapeake Bay in large numbers during May and June, with a smaller influx in November. The larvae use the brackish waters and freshwaters as nursery areas. Here, they metamorphose into juveniles and grow rapidly. By the fall, the young menhaden quadruple in size to reach 40-185 mm SL (1.6-7.3 in).
Maximum Size: Approximately 15".
Reproduction: Sexual maturity begins just before age three; these fish spawn from March to May, and again in September and October.
Migrations: The menhaden return to the shelf waters off the Bay ready to spawn (March-May). The young of the year leave the estuary in late fall and join the schools in southward migration. During the fall and early winter, most menhaden migrate south to the North Carolina capes, where they remain until March and early April.
Predators: Menhaden serve as prey for many fish and sea birds. A large crustacean parasite also commonly feeds off of the menhaden, attaching to the fish's mouth, thus giving menhaden another nickname: bugfish.
Commercial and Recreational Interest: Commercial.
Distinguishing Charecteristics: Moderately compressed body; silvery in color with a distinct black shoulder spot behind their gill opening.
Role in the Ecosystem
Menhaden form a critical link between the lower and upper levels of the Chesapeake Bay food web, because they are a key forage species for fish such as striped bass, weakfish, and bluefish and are filter feeders, grazing on planktonic organisms such as algae and zooplankton. Menhaden is the only forage species in the Chesapeake Bay that is also a major commercial fishery—the species is the largest fishery, by volume, in the Chesapeake Bay. More pounds of menhaden are landed each year than of any other fish in the United States other than pollock.
Menhaden is considered unfit for human food consumption due to its small size and high oil content, but the modern purse seine reduction fishery grinds menhaden into fish meal and oil for use as an ingredient in pet foods, livestock and aquaculture feeds, and various industrial products. East Coast landings of menhaden have ranged from 300,000 to 400,000 metric tons annually since the mid-1970s. Most of that catch comes from estuaries including the Chesapeake Bay and near-shore coastal waters, which are fished with a variety of gear, most commonly purse seines and pound nets. The purse-seine fishery for menhaden is extremely clean, resulting in less than one tenth of one percent by-catch of other species.
Did You Know?
Updated January 2012