Atlantic menhaden (Brevoortia tyrannus) occupy estuaries and coastal waters from northern Florida to Nova Scotia and are believed to consist of a single population. Adult and juvenile menhaden form large, near-surface schools, primarily in estuaries and nearshore ocean waters from early spring through early winter. By summer, menhaden schools stratify by size and age along the coast, with older and larger menhaden found farther north. During fall-early winter, menhaden of all sizes and ages migrate south around the North Carolina capes to spawn.
Sexual maturity begins as early as age one to just before age three, with major spawning areas from the Carolinas to New Jersey. The majority of spawning occurs primarily offshore (20-30 miles) during winter. Buoyant eggs hatch at sea, and larvae are carried into estuarine nursery areas by ocean currents. Juveniles spend most of their first year in estuaries, migrating to the ocean in late fall.
Menhaden are very efficient filter feeders. Water is pushed through specialized gill rakers that are formed into a basket that allows them to capture plankton. Menhaden are an important component of the food chain, providing a link between primary production and higher organisms by consuming plankton and providing forage for species such as striped bass, bluefish, and weakfish, to name just a few.
Schooling Atlantic menhaden. Photo ©ASMFC.
The Atlantic menhaden commercial fishery consists of a reduction fishery and a bait fishery. The reduction fishery, named because it processes the whole fish into fish meal, fish oil, and fish solubles, first began in New England during the early 1800s and spread south after the Civil War. The reduction fishery grew with the advent of purse seine after the Civil War in the mid-1800s. Purse seine landings reached a high point in the 1950s with peak landings of 712,100 metric tons (mt) in 1956 (Figure 1). At that time, over 20 menhaden reduction factories ranged from northern Florida to southern Maine. In the 1960s, the Atlantic menhaden stock contracted geographically, and many of the fish factories north of the Chesapeake Bay closed because of a scarcity of fish. Reduction landings dropped to a low of 161,000 mt in 1969. In the 1970s and 1980s, the menhaden population began to expand (primarily due to a series of above average year classes entering the fishery), and reduction landings rose to around 300,000-400,000 mt. Adult menhaden were again abundant in the northern half of their range and, as a result, reduction factories in New England and Canada began processing menhaden again by the mid-1970s. However, by 1989 all shore-side reduction plants in New England had closed, mainly because of odor abatement regulations.
During the 1990s, the Atlantic menhaden stock contracted again (as in the 1960s), largely due to a series of poor to average year classes. Over the next decade, several reduction plants consolidated or closed, resulting in a significant reduction in fleet size and fishing capacity. By 2005, there was only one remaining reduction plant in operation on the Atlantic coast processing menhaden into fishmeal and oil, which is located in Virginia and still operational today. The 2013 harvest of Atlantic menhaden for reduction was 131,034 mt, an 18% decrease from harvest in 2012 (160,627 mt) and 24% below average landings from 2010-2012 (172,600 mt). Seven purse-seine vessels landed Atlantic menhaden during the 2013 season. Most of the catch occurred in the waters off of Virginia and New Jersey.
The coastwide bait fishery supplies fishermen with bait for popular commercial (e.g., American lobster and blue crab) and sport fish (e.g., striped bass and bluefish), and has grown throughout its history along with the expansion of many fisheries that utilize menhaden as bait. Landings for bait have recently dipped due to the aforementioned reduction; levels for 2013 were 35,043 mt, 34% below the average landings during 2010-2012 (52,900 mt). However, in 2012, bait landings peaked at an all-time high of 63,540 mt. The bait fishery has increased in relative importance from North Carolina to New England. This is evident in the increasing percent of total menhaden landings that are attributed to the bait fishery. Between 2001 and 2012, the percent of total landings that were used for bait rose from 13% to a high of 28% in 2012. In 2013, bait harvest composed approximately 22% of the total menhaden harvest. In recent years, the majority of bait landings have been harvested from Virginia and New Jersey waters, followed by Massachusetts and Maryland.
The 2015 benchmark stock assessment indicates that Atlantic menhaden are neither overfished nor experiencing overfishing. Fishing mortality rates have remained below the overfishing threshold (2.98) since the 1960s, and have hovered around the overfishing target (1.03) through the 1990s. In 1999, fishing mortality dropped below the target and was estimated to be 0.27 in 2013 (the latest year in the assessment). In other words, fishing mortality has been decreasing throughout the history of the fishery, and is now 91% below the threshold and 73% below the target, meaning that overfishing is not occurring.
The biological reference point used to determine the fecundity target is defined as the mature egg production one would expect when the population is being fished at the threshold fishing mortality rate. Population fecundity, a measure of reproductive capacity, was estimated to be well above both the threshold and the target in recent years. In fact, in 2013, fecundity is estimated to have been 71% higher than the target value, which is calculated to be 100 trillion eggs. This means that the spawning stock in 2013 appears to be more than adequate to produce the target number of eggs, and thus the population is not overfished.
Atlantic menhaden are currently managed under Amendment 2, approved in 2012. Amendment 2 established a 170,800 mt total allowable catch (TAC) that began in 2013. The established TAC represents a 20% reduction from the average landings of 2009-2011 and an approximate 25% reduction from 2011 landings, which accounts for the recent decline seen in commercial landings. The TAC was established by Amendment 2 in response to the 2011 benchmark stock assessment , which reported that menhaden were not overfished but were experiencing overfishing.
The Amendment allocates the TAC on a state-by-state basis based on landings history of the fishery from 2009-2011. States are required to close their fisheries when the state-specific portion of the TAC has been reached; any overages must be paid back the following year. Under the Amendment, 1% of the overall TAC is set aside for episodic events. If the episodic event set aside quota is unused as of October 31, it is redistributed to all the states on November 1 based on the Amendment 2 allocation percentages. Amendment 2 also adopted new biological reference points for biomass which are based on maximum spawning potential, with the goal of increasing abundance, spawning stock biomass, and menhaden availability as a forage species.
In May 2015, the Atlantic Menhaden Management Board approved a total allowable catch (TAC) for the 2015 and 2016 fishing seasons at 187,880 mt per year, a 10% increase from the 2014 TAC. The increase responds to the positive findings of the 2015 Atlantic menhaden benchmark assessment which indicates the resource is not overfished nor experiencing overfishing relative to the current biological reference points. The TAC will be made available to the states/jurisdictions based on the state-by-state allocation established by Amendment 2. The Board also committed to moving forward with the development of an amendment to establish ecological based reference points that reflect Atlantic menhaden’s role as a forage species. The amendment will also consider changes to the current state-by-state allocation scheme. The Board has established a working group to aid in the development of issues to be addressed in the Public Information Document (PID) and draft amendment. The Board will meet later this year to review the working group’s progress. The PID is the first step in the Commission’s amendment process. It will gather information concerning the Atlantic menhaden fishery and resource and provide an opportunity for the public to identify and comment on major issues relative to the management of this species.