Scientist aboard the NEAMAP SNE/MA Nearshore Trawl Survey with a dominant, male black sea bass as evidenced by the nuchal hump right at the top of its head before its dorsal fin. Photo credit: NEAMAP.
Black sea bass (Centropristis striata) inhabit Atlantic coastal waters from the Gulf of Maine to the Florida Keys, concentrating in areas from Cape Cod, Massachusetts to Cape Canaveral, Florida. A temperate reef fish, black sea bass commonly inhabit rock bottoms near pilings, wrecks, and jetties. Black sea bass rely on their large mouth and swift ocean currents to catch prey, which include fish, crabs, mussels, and razor clams. Two distinct stocks of black sea bass exist along the Atlantic coast with overlapping ranges. The northern stock migrates seasonally. Black sea bass summer in northern inshore waters at depths of less than 120 feet and winter in southern offshore waters at depths of 240 to 540 feet. Spawning occurs off of New England in the late summer.
Black sea bass are protogynous hermaphrodites, which mean they start life as a female and then change sex to become males when they reach 9-13 inches (2 - 5 years of age). Thirty-eight percent of females in the Mid-Atlantic demonstrate sex reversal between August and April, after most fish have spawned. Even though some fish are males when they reach sexual maturity, most produce eggs when they first mature. Following transition, a sea bass will either become a dominant male, characterized by a larger size and a bright blue nuchal hump during spawning season (see accompanying photo), or a subordinate male that has few distinguishing features.
Black sea bass are highly sought by both commercial and recreational fishermen throughout the Mid-Atlantic. Fisheries change seasonally with changes in fish distribution. Inshore and more southern commercial fisheries primarily use fish pots and handlines, and when fish move offshore in the winter, they are primarily caught in trawl fisheries targeting summer flounder, scup, and Loligo squid. Recreational fisheries generally occur during the period that sea bass are inshore (May to September), but season duration varies among the states. Since the fishery management plan’s approval in 1997, the black sea bass commercial fishery has operated under a quota. The recreational fishery is restricted by a coastwide recreational harvest limit.
Commercial landings have been recorded since the late 1800s. Fish were primarily harvested by handlines until the early 1950s. From 1887 through 1948, commercial landings north of Cape Hatteras fluctuated around six million pounds. By 1952, with the emergence of the trap fishery, landings peaked at 22 million pounds. Since 1998, commercial landings have been primarily influenced by the commercial quotas. Between 1998 and 2007, landings averaged 2.8 million pounds. From 2008 to 2012, reduced quotas resulted in average landings of only 1.6 million pounds. Landings have since increased, reaching a high of 3.8 million pounds in 2017, and 3.3 million pounds in 2018. Commercial fishery discards historically represented a small fraction of total fishery removals from the stock at less than 0.4 million pounds per year, but have increased in recent years. In 2017, commercial discards were 1.78 million pounds. Otter trawls and fish pots/traps have accounted for the majority of the black sea bass landings in most states. Other important gear include handlines and lobster pots.
Black sea bass are also an important recreational species in the Mid-Atlantic, commonly caught using squid and natural bait. In 1965, over half of the total catch of black sea bass was credited to recreational fishing. Angling pressure increased markedly in the mid-1980s. In 1998 and 1999, recreational landings decreased substantially, which may be partially attributed to an increase in minimum size limits. Landings started to increase in 2000 and averaged 4.4 million pounds from 2000 to 2009. Recreational landings increased rapidly and peaked in 2016 at approximately 12 million pounds, and in 2017 dropped slightly to 11.4 million pounds. Recreational discards have also increased to about 85% of total catch over the last 10 years. Assuming a 15% hook and release mortality, in 2018, estimated mortality from recreational discards were estimated at 3.13 million fish, equal to 44% of the total recreational removals (harvest plus dead discards).
An operational assessment that incorporated new recreational harvest estimates was peer reviewed in August 2019. The assessment found that the black sea bass stock north of Cape Hatteras, North Carolina was not overfished and overfishing was not occurring in 2018 relative to revised reference points.
Starting in 2007, spawning stock biomass (SSB) increased rapidly and reached a peak in 2014 at over 76 million lbs., then decreased slightly. In 2018 SSB was estimated at 73.65 million pounds, 2.4 times the updated biomass target of 31.07 million lbs. The average fishing mortality in 2018 was 0.42, 91% of the updated fishing mortality threshold of 0.46. To account for the fact that black sea bass are protogynous hermaphrodites, which change sex from female to male, the assessment defined SSB as the total of male and female mature biomass to adjust for changes in sex ratio.
Recruitment of the 2017 year class as age 1 in 2018 was estimated at 16 million fish, well below the time series average. The 2011 year class was estimated to be the largest in the time series at 144.7 million fish and the 2015 year class was the second largest at 79.4 million fish. Despite uncertainty associated with the most recent year estimates, exploitable biomass is expected to decrease in coming years due to poor recruitment by the 2017 cohort along with declining abundance of the 2015 cohort. Over the past decade, the distribution of the fishery and catches has generally expanded northward.
Black sea bass is managed jointly by the Atlantic States Marine Fisheries Commission and the Mid-Atlantic Fishery Management Council (Council) under Amendment 13 to the Summer Flounder, Scup and Black Sea Bass Fishery Management Plan (August 2002) and its subsequent addenda (Addenda XII-XXXII). The objectives of the FMP are to reduce fishing mortality to assure overfishing does not occur, reduce fishing mortality on immature black sea bass to increase spawning stock biomass, improve yield from the fishery, promote compatible regulations among states and between federal and state jurisdictions, promote uniform and effective enforcement, and minimize regulations necessary to achieve the stated objectives.
The management program divides a total annual quota between the recreational fishery (51%) and the commercial fishery (49%). The recreational fishery is currently managed on a regional basis using a combination of minimum size limits, bag limits and fishing seasons to achieve a regional allocation of the recreational harvest limit (RHL). The coastwide commercial quota is divided among the states annually. Specific management measures for the commercial fishery are set by each state, which may include 1) minimum size limits, 2) minimum mesh requirements for trawls or 3) a moratorium on entry into the fishery and closed seasons.
Although the black sea bass fishery was declared rebuilt in 2009, the unique life history of the species contributes to uncertainty about the size of the stock. The response of this species, as well as other hermaphroditic species, to exploitation is not fully understood. Given these concerns, the Commission and Council approved a 3.52 million pound commercial quota and a 3.66 million pound RHL for the 2019 fishing season. Based on the 2019 operational stock assessment results indicating SSB is larger than previously thought and the stock status is positive, the Board approved a commercial quota of 5.58 million lbs and an RHL of 5.81 million lbs for 2020 and 2021.
In December 2018, the Board approved Addenda XXXI and XXXII to the FMP. Addendum XXXI adds to the suite of tools available for management, with particular focus on enhancing the compatibility of state and federal regulations, by allowing the use of conservation equivalency for recreational management starting in 2020. Conservation equivalency allows recreational management measures in federal waters measures to be waived, and instead requires recreational anglers to abide by the measures of the state in which they land their catch. The Board and Council will annually decide whether to enact conservation equivalency.
Addendum XXXII establishes an annual specifications process for developing recreational management measures. The Board will approve regional measures in early spring each year, based on technical committee analysis of stock status, resource availability, and harvest estimates. Public input on specifications will be gathered by states through their individual public comment processes. The specifications process will provide the Board more flexibility in adjusting measures, if necessary, to constrain harvest to the annual coastwide recreational harvest limit (RHL). Further, the process will enable the Board to consider a host of factors, including: regional equity; regulatory stability; species abundance and distribution; and late-breaking recreational harvest estimates.
In February 2021, the Board and MAFMC jointly approved several changes to the management program for black sea bass commercial fisheries. These changes include modifying the state allocations of the commercial black sea bass quota, adding the state allocations to the MAFMC's Fshery Management Plan (FMP), and modifying the regulations for federal in-season closures. The Board adopted the new allocations through Addendum XXXIII to the Summer Flounder, Scup and Black Sea Bass FMP, while the Council recommended these changes through an amendment to its FMP. These actions address significant changes in the distribution of black sea bass that have occurred since the original allocations were implemented under Amendment 13 in 2003 and also account for the historical dependence of the states on the black sea bass fishery.
Summer Flounder, Scup, and Black Sea Bass Commercial/Recreational Allocations Amendment
The Board and MAFMC developed a joint amendment to consider an adjustment to the allocations between the commercial and recreational fisheries for summer flounder, scup and black sea bass. The commercial and recreational allocations for all three species are currently based on historical proportions of landings (for summer flounder and black sea bass) or catch (for scup) for each sector. Recent changes in how recreational harvest is estimated have resulted in a discrepancy between the current levels of estimated recreational harvest and the allocations of summer flounder, scup and black sea bass to the recreational sector. Some changes have also been made to commercial catch data since the allocations were established. This amendment considers whether modifications to the allocations are needed in light of these and other changes in the fisheries. The amendment also considers options that would allow a portion of landings to be transferred between the commercial and recreational sectors each year, in either direction, based on the needs of each sector. At the April 2021 meeting of the Board and MAFMC, final action was postponed to allow for further development of the Recreational Reform Initiative. The Council and Board are now scheduled to take final action on the commercial/recreational allocation amendment at a joint meeting in December 2021. Additional information and updates on this amendment are available at: http://www.mafmc.org/actions/sfsbsb-allocation-amendment.