American eel (Anguilla rostrata) are a catadromous fish species, spending most of their life in freshwater or estuarine environments, traveling to the ocean as adults to reproduce and die. Sexually maturing eel migrate to spawning grounds located in the Sargasso Sea, a large portion of the western Atlantic Ocean east of the Bahamas and south of Bermuda. American eel are a panmictic stock, meaning that individuals from the entire range come together to reproduce. American eel found along the eastern coast of Mexico are from the same population as eel found in the St. Lawrence River in Canada.
American eel have a multitude of life stages: leptocephali, glass eel (also known as elvers), yellow eel, and silver eel. Yellow eel are the primary life stage harvested by commercial and recreational fishermen.
American eel are an important resource from both a biodiversity and human use perspective. They serve as an important prey species for many fish, aquatic mammals and fish-eating birds. Although fisheries are a fraction of what they were historically, eel support valuable commercial, recreational and subsistence fisheries.
From the 1970s to the mid-1980s, American eel supported significant commercial fisheries, with landings ranging from 2.5 -3.6 million pounds. Landings dropped to 1.6 million pounds in 1987 and have remained at low levels, ranging from 1.5 million to 700,000 pounds since then. State reported landings of yellow and silver eels in 2015 totaled approximately 884,000 pounds, 11% lower than 2014. Since 2010, increased demand for glass eels by foreign markets has led to a dramatic increase in the value of glass eels and record high prices of $2,000+ per pound. In 2015, glass eel harvest from Maine and South Carolina totaled 5,441 pounds, a decrease from 2014. In 2015, total eel landings (glass, yellow and silver eel combined) were valued at approximately $13.6 million.
Recreational harvest has been on the decline since its peak in 1985 at 160,000 eel. Harvest was last estimated to be around 6,000 in 2009 (the last year the Marine Recreational Information Program collected recreational data on American eel). Given the limited scope of the fishery in recent years, there is limited monitoring of recreational catch by the states.
From a biological perspective, much is still unknown about the species. Information is limited about their abundance, status at all life stages, and habitat requirements. According to the 2017 stock assessment update, the American eel population remains depleted in U.S. waters. The stock is at or near historically low levels due to a combination of historical overfishing, habitat loss, food web alterations, predation, turbine mortality, environmental changes, toxins and contaminants, and disease. The assessment updates the 2012 American Eel Benchmark Stock Assessment with data from 2010-2016. Trend analyses of abundance indices indicated large declines in abundance of yellow eels during the 1980s through the early 1990s, with primarily neutral or stable abundance from the mid-1990s through 2016. Total landings remain low but stable. Based on these findings, the stock is still considered depleted. No overfishing determination can be made based on the analyses performed.
In 2011, the U.S. Fish and Wildlife Service (USFWS) initiated a status review of American eel under the Endangered Species Act (ESA) to assess the health of the population and the magnitude of threats facing the species. On October 7, 2015, USFWS announced that the American eel is stable and does not need protection under the ESA. Nonetheless, for the species’ long-term stability, the agency recommends continuing efforts to maintain healthy habitats, monitor harvest levels, and improve river passage for migrating eels. In 2014, the International Union for the Conservation of Nature (IUCN) listed American eel as “Endangered” on the Red List. The IUCN assesses flora and fauna globally to determine their conservation status (not evaluated to extinct). While the IUCN list has no legal implications, it is an important metric that accounts for a variety of factors including habitat, threats, potential stresses, and research status. Given these findings, and recent actions taken by the Commission and its member states, the Commission remains committed to closely monitoring American eel fisheries and the status of the resource, and making adjustments to the management program as necessary, to ensure stock rebuilding.
American eel are a challenging species to conserve and manage on a coastwide basis for a number of reasons. During its life-span the American eel will have navigated through and resided in a wide range of habitats, from the oceanic waters of the Sargasso Sea to the brackish waters of coastal estuaries and the inland freshwater river systems. Additionally, throughout this journey, eel will have been under a myriad of management authorities, from international to multiple federal, state and local governments. Life history characteristics such as late age of maturity and a tendency to aggregate during certain life stages further confound conservation efforts.
American eel are managed by the Commission in territorial seas and inland waters along the Atlantic coast from Maine to Florida. Increasing demand for eel by Asian markets and domestic bait fisheries, coupled with concern about declining eel abundance and limited assessment data, spurred development of the first Interstate Fishery Management Plan (FMP) for American Eel in the mid-1990s. The plan, approved in 1999, provided several reasons why heavy harvest pressure may adversely affect American eel populations: (1) American eel have a slow rate of maturation, requiring eight to 24+ years to attain sexual maturity; (2) glass eel tend to aggregate seasonally during migration, making them vulnerable to directed harvest; (3) harvest of yellow eel is a cumulative stress, over multiple years, on the same yearclass; and (4) all fishing mortality occurs prior to spawning.
In response to the 2012 stock assessment, which indicated that the American eel population in U.S. waters is depleted, the Commission approved Addendum III (August 2013) and Addendum IV (October 2014) to the Interstate FMP with the goal of reducing mortality and increasing conservation of American eel stocks across all life stages. Addendum III establishes new management measures for both the commercial (glass, yellow, and silver) and recreational eel fisheries, and implements fishery-independent and fishery-dependent monitoring requirements. Addendum IV establishes a 907,671 pound coastwide quota for yellow eel fisheries, reduces Maine’s glass eel quota to 9,688 pounds (2014 landings), and allows for the continuation of New York’s silver eel weir fishery in the Delaware River.
For yellow eel fisheries, a coastwide quota was set for the 2015 fishing year along with two management triggers that would require implementation of state-specific allocations if met. The established management triggers are: (1) exceeding coastwide quota by more than 10% in a given year, or (2) exceeding the coastwide quota for two consecutive years regardless of the percent overage. If either trigger is met then states must implement state-specific allocation based on average landings from 2011-2013.
Per the Addendum, Maine maintains daily trip level reporting and requires a pound-for-pound payback in the event of quota overages in its glass eel fishery. Additionally, the Maine is required to implement a fishery-independent life cycle survey covering glass, yellow and silver eels within at least one river system. The Addendum specifies that these requirements would also be required for any jurisdiction with a commercial glass eel fishery harvesting more than 750 pounds.
Addendum IV provides states/jurisdictions the ability to request limited participation in the glass eel fishery based on conservation programs enacted after January 1, 2011, and given there is an overall benefit to American eel populations. Examples of conservation programs include, but are not limited to, habitat restoration projects, fish passage improvements, or fish passage construction. The Addendum also provides opportunities for a limited glass eel harvest for domestic aquaculture purposes and allows the continuation of New York’s Delaware River silver eel weir fishery under a transferable license cap, limited to nine permits annually.
In 2016, Maine implemented its life cycle monitoring program as required by Addendum IV. However, due to administrative and gear issues, as well as drought conditions, sampling was incomplete. An improved program was implemented in 2017. In 2017, the American Eel Management Board maintained the continuance of North Carolina’s Aquaculture Plan, which allows up to 200 pounds of glass eels to be harvested for aquaculture purposes.