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/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 eventually 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 43,131 mt (95 million pounds) in 2018.
The 2018 Benchmark Stock Assessment, conducted by the Northeast Fisheries Science Center, provided an updated picture of stock health. While Atlantic herring are not overfished and overfishing is not occurring, the report highlighted concerns about trends in recruitment and spawning stock biomass. Recruitment, a measure of how many herring are born into the population, has been below the time series average for the last five years. In particular, 2016 recruitment was the lowest on record at 1.7 million fish. While recruitment has been variable throughout time, recent and continuing low levels of recruitment indicate that there will be fewer fish available to harvest in future years. Spawning stock biomass (SSB), the portion of the population that is reproducing, has also been lower in recent years. In 2017, SSB was estimated at 141,473 mt, below the SSB threshold of 189,000 mt (417 million pounds). Fishing mortality has decreased in recent years, with a 2017 level of 0.45, below the fishing mortality threshold of 0.51. The data used in the assessment came from both fishery-dependent and -independent data, incorporating commercial landings and relying on the NEFSC trawl survey.
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 A1. 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 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, with 2016 recruitment levels the lowest on record.
For 2020 fishing season, the Council and the Commission set the ACL at 25.5 million pounds (11,571 metric tons). The ACL is further subdivided by the Atlantic herring management areas as follows: Area 1A = 7.3 million pounds, Area 1B = 1.1 million pounds, Area 2 = 7.1 million pounds, and Area 3 = 9.9 million pounds. After adjusting for the research set-aside, the 30 mt fixed gear set-aside, and the 8% buffer (Area 1A closes at 92% of the sub-ACL), the Area 1A sub-annual catch limit (sub-ACL) is 6.8 million pounds (3,076 mt). For 2020, the Area 1A sub-ACL is distributed seasonally with 72.8% of the quota available from June through September and 27.2% allocated from October through December. 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.
In October 2019, the Board initiated Draft Addendum III to consider new approaches for managing the Area sub-ACL under low quota scenarios for the 2020 fishing season and beyond. This action responds to the challenges encountered in managing the reduced sub-ACL based on the 2018 benchmark stock assessment, which highlighted declining trends in recruitment and spawning stock biomass. Draft Addendum III also considers expanding landing provisions across different permit categories within the days out program. The Draft Addendum is currently available for public comment and more information can be found at: http://www.asmfc.org/uploads/file/5e43192bpr07AtlHerringDraftAddendum_PublicHearings.pdf The Board will consider approval of Draft Addendum III at the Commission’s Spring Meeting in May 2020 and may adjust the current 2020 seasonal quota allocation based on the final approved Addendum.
Days out is the primary effort control measure for the Area 1A fishery. States involved in the Atlantic herring fishery are allowed 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, participially 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. The days our measures for the 2020 fishing season will be set in May 2020.
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, October 4 and October 4, 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/.