Atlantic herring (Clupea harengus) are oceanic, plankton-feeding fish that occur in large schools and inhabit coastal and continental shelf waters from Labrador to Virginia. Juveniles (called sardines) undergo seasonal inshore-offshore migrations. Sardines are abundant in shallow, inshore waters during the warmer months of the year. Adults (age three and older) migrate south from summer and fall spawning grounds in the Gulf of Maine and Georges Bank to spend the winter in Southern New England and the Mid-Atlantic.
Herring spawn as early as August in Nova Scotia and eastern Maine and during October and November in the southern Gulf of Maine, Georges Bank, and Nantucket Shoals. Spawning habitat consists of rock, gravel, or sand bottoms, ranging in depth from 50-150 feet. Females can produce between 30,000 and 200,000 eggs each. Schools can produce so many eggs that the ocean bottom is covered in a dense carpet of eggs several centimeters thick. Eggs hatch in 10-12 days depending on water temperature. By their fourth year, fish are about 10” in length and may grow to about 15” (1 ½ pounds) by 15 to 18 years old. Herring are filter feeders preying entirely on plankton. They usually feed at night following the massive vertical migrations of zooplankton that inhabit deep waters by day and surface waters by night.
Atlantic herring are one of the most important species in the Northeast because of the vast role they play in the marine ecosystem and their importance to fishermen. Herring form the base of the food web as a forage fish for marine mammals, seabirds and many fish throughout the Mid-Atlantic and Northeast. Schooling herring serve as an important prey resource for migrating whale and dolphin populations on which eco-tourism activities, such as whale watching, depend. Atlantic herring also provide effective and affordable bait to lobster, blue crab and tuna fishermen, and are sold as canned sardines, steaks and kippers. They are also a valued commodity overseas where they are frozen and salted. Since 2000, the ex-vessel value of commercial herring landings has averaged about $30 million/year.
The commercial herring fishery in New England developed in the late 19th century, spurred by the development of the canning industry. The lobster fishery developed about the same time, creating a market for herring as bait. Commercially landed herring are caught using purse seines and mid-water trawls. Catch in the Atlantic herring fishery increased in the 1960s, peaking in 1986 at 477,767 mt (1.05 billion pounds), largely due to a foreign fishery which developed on Georges Bank. Catch declined in the 1980s and averaged 78,164 mt (172 million pounds). Landings in the 2000s were fairly stable around 113,358 mt (250 million pounds) but have decreased over the last five years to approximately 57,101 mt (125 million pounds) in 2018., and 17,836 mt (39 million pounds) in 2019.
A 2020 Management Track Assessment was completed by the Northeast Fisheries Science Center and peer-reviewed in June. The assessment is an update from the 2018 benchmark, and indicates the stock is overfished while overfishing is not occurring. While the traditional modeling framework (ASAP) is unchanged, the new assessment used different methods to produce biological reference points (BRPs) and short-term projections. The BRPs were estimated using only the selectivity from the U.S. mobile fleet because the proportion of catch from the fixed gear fleet has increased significantly in recent years. The fixed gear fleet, which is predominantly Canadian catch and not managed by catch quotas, harvests a higher proportion of younger fish than the mobile gear fishery, which influences the overall selectivity pattern and BRPs calculated using the method from the previous assessment. However, short-term projections include total harvest so that projected probabilities and stock status are informed by all stock removals. The assessment also indicates recruitment estimates are highly variable but have remained at low levels from 2013-2019, which introduces an additional source of uncertainty in short-term projections.
The Commission manages Atlantic herring under Amendment 3 to the Interstate Fishery Management Plan, which was approved for management in February 2016 and implemented on June 1, 2016. The Amendment refines the spawning closure system and modifies the fixed gear set-aside. The Amendment consolidates prior amendments (and associated addenda) and recent management decisions into a single document; it is now the comprehensive document for Atlantic herring management in state waters.
Because herring can be found in state and federal waters, there are complementary management plans between the Commission and New England Fishery Management Council (Council) which set annual quotas, called annual catch limits (ACL), for three management areas and two sub-areas. The ACLs for these areas are set based on the maximum sustainable yield that allows for a sustainable harvest but leaves enough herring for fish, birds and marine mammals. While the plans for state and federal waters share management boundaries, there are a few differences between the plans. The Council prohibits mid-water trawling from June 1 - September 30 in Area 1A (inshore Gulf of Maine). The Commission plan includes spawning closures and a “days out” provision. During a spawning closure or a “day out” of the fishery, vessels participating in other fisheries may possess no more than 2,000 pounds of Atlantic herring per trip. In addition, all vessels traveling through Area 1A must have all gear stowed.
In May 2017, the Commission approved the continued use of the GSI-based forecast system to predict when the population will be spawning and when spawning closures should be set based on the development of herring gonads (reproductive organs) in Area 1A. GSI stands for gonadosomatic index, the ratio of the weight of a female herring’s ovaries to her body weight. As female fish get ready to spawn, their ovaries become heavier and the GSI increases. Scientists use the observed rate of increase in the GSI to predict when spawning will occur and when the fishery should be closed.
In April 2019, the Board approved Addendum II to strengthen spawning protections in Area 1A (inshore Gulf of Maine) by initiating a closure when a lower percentage of the population is spawning (from approximately 25% to 20%), and extending the closure for a longer time (from four weeks to six weeks). The Addendum also modifies the trigger level necessary to reclose the fishery, with the fishery reclosing when 20% or more of the sampled herring are mature but have not yet spawned. These changes to spawning protections are in response to the results of the 2018 Benchmark Stock Assessment which showed reduced levels of recruitment and spawning stock biomass over the past five years, including the lowest levels of recruitment on record.
For the 2022 fishing season, the Council and the Commission set the ACL at 9 million pounds (4,098 mt), which was later adjusted to 8.4 million pounds (3,813 mt) to account for overages in 2020. The ACL is further subdivided into sub-ACLs by the Atlantic herring management areas as follows (accounting for adjustments due to 2020 catch overages/underages): Area 1A = 2.4 million pounds (1,075 mt), Area 1B = 0 pounds (0 mt), Area 2 = 2.9 million pounds (1,295 mt), and Area 3 = 4.0 million pounds (1,817 mt). After adjusting for the 30 mt fixed gear set-aside and the 8% buffer (Area 1A closes at 92% of the sub-ACL), the 2022 Area 1A sub-ACL is 961 mt. There is no research-set-aside for 2022. The Board established the following seasonal allocations for the 2022 Area 1A sub-ACL: 72.8% available from June 1 – September 30 and 27.2% available from October 1 – December 31. Directed fisheries within a management area close when 92% of the sub-ACL has been harvested, and the stock-wide fishery closes when 95% of the ACL is projected to be reached.
Days out is the primary effort control measure for the Area 1A fishery. States involved in the Atlantic herring fishery are able to extend the fishery by controlling fishing effort (fishing days) through landing restrictions. The goal is to provide a consistent supply of herring to the market by controlling landings, particularly early in the season when herring may be localized in Area 1A.
Maine, New Hampshire and Massachusetts continue to modify days out of the fishery during the season to prolong the fishery in Area 1A, making herring available during peak demand. TThe Area 1A sub-annual catch limit (ACL) is 961 metric tons (mt) after adjusting for the overage from 2020, the 30 mt fixed gear set-aside, and the fact that Area 1A closes at 92% of the sub-ACL. In October 2021, the Board established the following seasonal allocations for the 2022 Area 1A sub-ACL: 72.8% available for season 1 (June 1 – September 30) and 27.2% available for season 2 (October 1 – December 31). The measures can be found here.
Atlantic herring captured as part of the Northeast Fisheries Science Center's (NEFSC) Pelagic Trawl Survey. Photo credit: NEFSC.
The three inshore Atlantic herring spawning areas of eastern Maine, western Maine, and Massachusetts-New Hampshire have independent closures during the fall that may begin on the default dates of August 28, September 23 and September 23, respectively. Actual closure effective dates are determined using the GSI-based forecast system. This method was developed by the Technical Committee, then tested and evaluated for effectiveness during the 2016 fishing season. The GSI-based spawning monitoring system tracks reproductive maturity to align the timing of spawning area closures with the onset of spawning. The modeling efforts to forecast the spawning closures are available at http://www.massmarinefisheries.net/herring/