Atlantic sturgeon being measured as part of a Cooperative Federal/State/Industry Atlantic Sturgeon Bycatch Reduction Survey. Photo © ASMFC.
Atlantic sturgeon (Acipenser oxyrhynchus) are ancient fish dating back at least 70 million years, and can be found along the entire Atlantic coast from Florida to Labrador, Canada. They are anadromous, migrating from the ocean into coastal estuaries and rivers to spawn. Atlantic sturgeon may live up to 70 years old, with females reaching sexual maturity between the ages of seven to 30, and males between the ages of five to 24.
Typically sturgeon inhabiting the southern part of the species range mature faster and grow larger than those in the northern part of the range. Females reach sexual maturity between the ages of 7 and 30, and males between the ages of 5 and 24. The number of eggs that a female produces increases with age and size, which means that older and larger females are more valuable to the population because they produce more eggs (up to eight millions eggs per spawning event) than younger, smaller females (estimated 400,000 eggs per spawning event).
Most juveniles remain in their natal river from one to six years before migrating back out to the ocean. Little is known about the movements of Atlantic sturgeon when they are at sea. As juveniles, Atlantic sturgeon feed on flies, worms, shrimps, and small mollusks and crustaceans. As adults, they are opportunistic feeders and prey mainly on mollusks, snails, worms, shrimps and benthic fish. Very little is known about their natural predators.
Since colonial times, Atlantic sturgeon have supported commercial fisheries of varying magnitude. In the late 1800s, they were second only to lobster among important fisheries, with landings estimated at seven million pounds per year just prior to the turn of the century. Overharvesting of sturgeon for flesh and eggs (known as caviar) continued through the 1990s until the Commission and federal government implemented a coastwide moratorium in late 1997 and early 1998. Because the population has been severely overfished, the Commission's Fishery Management Plan for Atlantic Sturgeon calls for a coastwide moratorium through at least 2038, in order to build up 20 year classes. Several facilities culture Atlantic sturgeon for research purposes.
Very little is known about the Atlantic sturgeon’s stock status. Reliable data are difficult to obtain because many river systems have few fish, and rivers with more fish are often not easily sampled. Several states have been conducting long-term monitoring of Atlantic sturgeon. Data from two of these efforts are provided in the accompanying graphs, which depict catch per unit effort (CPUE) for fishery-independent surveys conducted by North Carolina and New York. Both surveys have experienced significant fluctuations in recent years. However, in 2013, North Carolina’s CPUE was the second highest value in the past twenty years. Further, the spike of juveniles seen in New York’s survey are believed to be a direct result of the New York’s moratorium in 1997 and the concomitant increase of spawning fish in the Hudson River.
NOAA Fisheries has investigated the status of Atlantic sturgeon with regard to its listing under the Endangered Species Act (ESA) three times since the Commission’s implementation of Amendment 1 in 1998. The first two status reviews, conducted in 1998 and 2005, concluded that listing was not warranted. In February 2012, as a result of the last status review initiated in 2009, NMFS published a final rule declaring the Gulf of Maine DPS as threatened and the remaining four DPSs (New York Bight, Chesapeake Bay, Carolina and South Atlantic) as endangered (effective April 2012). The status review determined that the most significant threats to all of the distinct population segments (DPSs) are bycatch mortality, poor water quality, lack of adequate state and/or federal regulatory mechanisms, and dredging activities. Additional stressors include habitat impediments and ship strikes. NMFS published an Interim Final 4(d) Rule for the threatened Gulf of Maine DPS in December 2013 which essentially provides the same protection as an endangered listing.
In response to the 2012 ESA listing, the Atlantic Sturgeon Board initiated the development of a coastwide benchmark stock assessment for Atlantic Sturgeon to evaluate stock status, stock delineation, and bycatch. In order to allow for the most comprehensive assessment, and based on the Atlantic Sturgeon Stock Assessment Subcommittee’s (SAS) recommendation, the Board decided to set the completion date for 2017 so that the most recent data from studies currently underway can be incorporated. For example, several assessment approaches at the DPS or stock-level would become possible from the analysis of genetic samples currently underway at the U.S. Geological Survey’s Leetown Science Center in West Virginia. This past May, the SAS identified each task of the assessment from data needs to modeling approaches, and the time it will take to complete each task to ensure the benchmark assessment is completed on schedule. Currently, the Bycatch and Tagging Working Groups are developing methodologies for their respective parts of the assessment, while each State actively updates their data through the terminal year of the assessment.
Atlantic sturgeon is managed in the U.S. through Amendment 1 and its associated Addenda I-IV. The primary goal of the amendment is to achieve stock recovery. Under Amendment 1, each state and jurisdiction “must maintain complete closure, through prohibiting possession of Atlantic sturgeon, and any and all parts thereof including eggs, of any directed fishery for and landings of Atlantic Sturgeon until the fishery management plan is modified to reopen fishing in that jurisdiction.” Exceptions to the moratorium on possession were approved via Technical Addendum #1 (2000) for the purposes of scientific research and educational display. The Amendment also addresses Atlantic sturgeon mortality associated with bycatch from other fisheries.
Addendum I (2001) to the Interstate FMP for Atlantic Sturgeon exempts the State of Florida from the possession moratorium for the purposes of developing private aquaculture facilities for cultivation and propagation of the species. Addendum II (2005) exempts a private company in North Carolina from the moratorium on possession, propagation, and sale of Atlantic sturgeon meat and eggs, and allows a Canada-based exporter to export Atlantic sturgeon fry and fingerlings into North Carolina. Addendum III (2006) similarly allows a private company in North Carolina to import Atlantic sturgeon from a Canada-based exporter. Addendum IV (2012) updates habitat information for Atlantic sturgeon and identifies areas of concern and research needs.