Atlantic Herring have a high intrinsic rate of increase, estimated to range between 0.5 to 1.2 (NEFMC 1999; Fishbase 2009). Most Atlantic herring reach sexual maturity at 3 to 4 years of age, although this value, as well as growth rates, appears to be density dependent and may vary annually with population size; maximum age of Atlantic herring is 15-18 years, although exceeding 12 years of age is rare (Stevenson and Scott 2005).

Large and complex spawning aggregations, a tendency for individuals to repeatedly return to natal spawning grounds, and the desirable high fat content of spawning individuals make herring susceptible to fishing pressure at certain times of the year (NEFMC 2006).

Fecundity varies with the size of the female from 44,000 eggs for smaller individuals (25 cm) to 220,000 eggs for larger individuals (36 cm) (Stevenson and Scott 2005). This is an 'average' fecundity for fin-fish, thus no points were added.

The Atlantic herring is distributed throughout the northern Atlantic Ocean. In the western Atlantic, herring is found in southwestern Greenland and the Canadian and U.S. coast from Labrador to South Carolina. In the eastern Atlantic herring is found in northern Bay of Biscay, northward to Iceland and southern Greenland and eastward into the Baltic and Arctic reaches of Spitzbergen and Novaya Zemla (Fishbase 2009; FAO 2007). We consider this to be a medium size range.

The most recent population assessment was performed by the Canadian Department of Fisheries and Oceans (DFO) in 2006. The Transboundary Resource Assessment Committee (TRAC) established the biomass of Atlantic herring as approximately 1 million mt and BMSY as 629,000 mt (TRAC 2006). Biomass is therefore estimated at approximately 158% of BMSY. Total catch of Atlantic Herring by all countries was 2.2 million tonnes in 2006 (FAO 2008).

Although there appear to be discrepancies between the different models used to evaluate Atlantic herring fluctuations in recent decades, the general trend is clear. Overfishing and exploitation of the Georges Bank fishery during the 1960s caused a collapse of the offshore fishery, resulting in a very low abundance in the 1970s and 1980s. This was followed by recovery in the 1990s. Currently, the fishery is considered recovered as there is a large population present on Georges Bank and a stable population present in the inshore Gulf of Maine Fishery (Overholtz et al. 2004). However, concerns that the inshore Gulf of Maine Fishery may be susceptible to over-fishing (Stevenston and Scott, 2005) has resulted in management actions in recent years (NEFMC 2006a).

The species is not overfished and overfishing is not occurring (ASFMC 2007, NMFS 2007). The species is not listed as 'depleted', 'endangered', or 'threatened'.

Since the collapse of the Georges Bank fishery, the population biomass has increased steadily from 105,000 mt in 1982 to 1.3 million in 2000. Population recovery in the 1990s was due in part to recruitment from two particularly large year classes in 1994 and 1998. The current population biomass has decreased slightly to 1.0 million mt in 2005 (TRAC 2006).

Following collapse of the offshore fishery and the resulting heavy fishing on the Gulf of Maine inshore areas, only fish aged 2 and 3 years were well represented in the landings. However, since the early 1990s surveys indicate that the age structure has expanded and herring ages 2 through 8 are more prevalent in the population (Overholtz 2007). Age distribution is considered functionally normal (Overholtz, pers. comm., 2007).

The Atlantic herring is considered a very important prey species in the North Atlantic ecosystem for numerous fish, marine mammals and seabirds. Major fish and marine mammal predators include spiny dogfish, silver hake, harbor porpoise, fin back whales, humpback whales and pilot whales. The Atlantic herring is also an important food source for many commercial and recreational fish species such as Atlantic cod, bluefin tuna, bluefish, striped bass, haddock, Atlantic halibut, and pollock (NEFMC 2003).

Current levels of Atlantic herring abundance are not known to negatively affect the structure of the food web. There is a growing awareness and recognition among fishery managers that changes in fishery practices can alter the seasonal availability of herring as food for other species, and this overall issue has been considered during the implementation of recent herring management measures (NEFMC 2006a).

Fishing methods used in the Atlantic herring fishery include paired mid-water trawl, single mid-water trawl, purse seines, stop seines and weirs, although the first three dominate by capturing 99% of the landings (NEFMC 2006c, NEFMC 2004, Overholtz et al. 2004). Mid-water trawls and purse seine fisheries are generally considered 'clean' fisheries that cause minimal damage to habitats.

Atlantic herring utilize a variety of coastal and offshore resources during their lifespan. These habitats include coarse substrate (rocks, gravel, shell fragments, etc.) used for egg beds; estuarine and nearshore waters used during larval and juvenile development; and inshore/offshore continental shelf and deeper waters used by older juveniles and adults.

These habitat areas are likely healthy enough to continue supporting the Atlantic herring.

The ASFMC (2007b) identifies threats to Atlantic herring habitat as nonpoint and point source pollution/contamination, destructive agricultural and silvicultural practices, natural disturbances such as coastal storms, and human activities such as coastal development, bottom trawling and marine construction activities.

Managers have implemented spawning closures for inshore portions of herring fishery. The closures commence around mid-August to mid-September, depending on the location, and last approximately four weeks. In order to ease fishing pressure on the inshore areas, the offshore fishing grounds are not subject to the spawning restrictions. This is meant to encourage fisherman to move to offshore locations where the Total Allowable Catch has not been fully harvested (ASMFC 2006).

The inshore fishery is also limited to only purse seine and fixed gear fisheries annually from June to September to ease fishing pressure when it could otherwise increase to meet demands of the lobster bait industry (NEFMC 2006a).

No innovations are necessary because gear effects of mid-water trawl and purse seine fisheries are minimal.

Gear effects of mid-water trawl and purse seine fisheries are minimal.

The western Atlantic herring populations are managed by both the U.S. National Marine Fisheries Service and the Canadian Department of Fisheries and Ocean (DFO), as well as the New England Fishery Management Council, Atlantic States Marine Fisheries Commission, and numerous state governments. In the western Atlantic, there are three discrete spawning populations, two in the U.S. and one in Canada. The three populations are managed as one transboundary resource by both federal governments, due to the mixed nature of herring populations outside of spawning season (Overholtz et al. 2004, Stevenson and Scott 2005). Management of the species applies to the three separate Atlantic herring population components and the entirety of their range in the northwestern Atlantic from Labrador to Cape Hatteras.

In the U.S., both the NEFMC and the ASMFC work together to regulate the fishery in federal and state waters, respectively. The NEFMC implemented the species' first Fishery Management Plan (FMP) in 1978 (which was withdrawn in 1982) and the ASFMC adopted an Interstate FMP in 1983, amended in 1999 and 2006 (NEFMC 2006a). The most recent NEFMC FMP was issued in 1999 and amended in 2006.

Prior to the current regulation by NEFMC and ASFMC, ineffective or non-existent management of the offshore Georges Bank fishery from 1961-1976 was characterized by heavy fishing from foreign fleets, inflated catch quotas and the targeting of spawning aggregations (NEFMC 1999). This led the offshore Atlantic herring population to collapse and resulted in low abundance throughout the 1970s into the mid-1980s until the population showed signs of increase in 1985 and recovery in the 1990s (NEFMC 1999).

The current Atlantic herring fishery is not overfished and overfishing is not occurring (ASMFC 2007, NMFS 2007). The Atlantic herring received a perfect score (4/4) in the NMFS Fish Stock Sustainability Index, reported as part of the Status of U.S. Fisheries (NMFS 2007) due to the status of the fishery and population biomass.

Some of the current management goals include: long-term sustainability and achievement of optimum yield, protection of spawning components, maintaining proper population age structure, providing an orderly development of the inshore and offshore fishery areas, minimizing discard waste, and preventing excess capacity in the harvesting sector (NEFMC 2006a).

In addition to updating new stock assessment data, the 2006 Amendment 1 to the 1999 NEFMC FMP was implemented to address new management issues. These included the need for a limited access program, measures to address the importance of herring as a forage species, and the localized depletion of inshore Gulf of Maine stocks (NEFMC 2006a).

The NEFMC and NMFS recently reduced the Total Allowable Catch in the Gulf of Maine inshore area (the most heavily fished area) from 60,000 mt to 50,000 mt for the 2007-2009 fishing years (Federal Register 2007b; NEFMC 2006b), and there is a proposal to further reduce this to 45,000 mt in the 2008 and 2009 fishing years (Steele, pers comm., 2007). These reductions by NMFS and the NEFMC are intended to prevent overfishing and ensure long-term sustainability of the resource.

The Atlantic herring resource is well studied due to the historic nature of the fishery and extensive management activity. Since 2005, fishery managers have issued an updated Essential Fish Habitat Sourcing Document (Stevenson and Scott, 2005), an updated population assessment (TRAC 2006), the Amendment 1 to the NEFMC 1999 FMP (NEFSC 2006a) and Amendment 2 to the ASFMC Interstate FMP (ASFMC 2006). Recent FMP amendment activity involved thorough analysis of both population and fishery status, as well as the effects of management actions.

To comply with federal fishery laws, managers must consider how fishing practices affect the essential fish habitat (EFH) of Atlantic herring and other federally managed species. As a result, habitat impacts are a relatively large focus of the fishery and habitat is relatively well studied. NMFS has identified Atlantic herring EFH, and published updated EFH information in 2005 (Stevenson and Scott 2005).

There is also increasing consideration of the effects of fishery practices on the availability of herring as food for other species in the North Atlantic ecosystem (NEFSC 2006a). Although food web and ecosystem effects are considered by managers, these are complex interactions which likely require additional data and research to ensure effective management.

A recovery plan is not needed because the fishery is not overfished and overfishing is not occurring (ASMFC 2007a; NMFS 2007).

Managers introduced measures in 2006 to address possible overcapitalization of the Atlantic herring fishery. Among the four designated fishing areas, the Gulf of Maine inshore area has been subject to a relatively higher fishing pressure, capturing over 60% of the total catch and facing closures each year as Total Allowable Catch is achieved (NEFSC 2006a). The NEFMC has proposed a proactive approach to this issue by recommending a limited access program for all herring management areas, not just the Gulf of Maine inshore area, since the capacity in other fishing areas appears to be increasing (NEFMC 2006a).

Bycatch data for the herring fishery is collected through Vessel Trip Reports (VTRs), Interactive Voice Response Reports (IVRs), NMFS/NEFSC Sea Sampling Data, and various other foreign catch reports and state observer data (NEFMC 2006c).

NMFS Sea Sampling Data includes bycatch information from 1994 through 2004 (NEFMC 2006c). Of 156 purse seine and mid-water trawl trips (both paired and single trawl) observed during the 11 year period, bycatch comprised 1.80% of the catch. The bycatch percentage within each fishing method is: paired mid-water trawl (1.44%), purse seine (2.04%), and single mid-water trawl (3.68%). Over 95% of the bycatch was comprised of Atlantic herring (68%) and spiny dogfish (27%). Vessels filled to capacity is a common reason for discard of Atlantic herring, as is capture of undersized individuals and spawning adults (NEFMC 1999). Other bycatch species in the herring fishery include redfish, mackerel, haddock, pollock, and cod.

Preliminary bycatch observed during 2005 herring fishery trips was estimated at 2.69% of the total catch (NEFMC 2006c).

There is documented bycatch of protected marine mammals in herring fishery (ASFMC 2006, NEFMC 2006a, NEFMC 2006c). This includes mortality of pilot whales and the Atlantic white-sided dolphin, primarily in the offshore mid-water trawl fishery (ASFMC 2006). There is also documented bycatch of the harbor porpoise with mid-water trawl fisheries, although this appears less common in recent years than pilot whale or white-sided dolphin bycatch (ASMFMC 2006). Harbor porpoise, gray seals and harbor seals are known bycatch of both purse seine and fixed gear (i.e., weir) fisheries but are often released alive (NEFMC 2006a). Observer coverage in the herring fishery was recently increased with the goal of obtaining additional information about bycatch and protected species interactions (NEFMC 2006a). Lack of data and observer coverge has long been an issue in the herring fishery, which has made it difficult to fully understand the extent of bycatch and effects on protected species.
The NMFS Protected Species Division maintains an annual List of Fisheries which categorizes fisheries according to impacts to marine mammals. The herring mid-water trawl fishery (including paired trawl) is listed in Category II for occasional serious injury and mortality; the Gulf of Maine Atlantic herring purse seine and stop seine/weir are in Category III for remote likelihood of marine mammal interactions (Federal Register 2007, NEFMC 2006c).

The fishery will likely have little effect on bycatch species since the bycatch ratio is relatively low and is primarily limited to two species (one being the target species, Atlantic herring, discarded due to filled vessels, undersized individuals or spawn herring).

Although there are no management measures to specifically reduce bycatch, current practices in the fishery may help to limit bycatch such as requiring vessels to record bycatch data, review of these reports annually by fishery managers, restrictions on larger vessels that can have higher bycatch rates, spawning closures, and counting discards towards the overall Total Allowable Catch (ASFMC 1999, NEFMC 1999).