American lobster (Homarus americanus) is a bottom-dwelling crustacean, widely distributed over the continental shelf of North America. In the inshore waters of the US, it is most abundant from Maine through New Jersey, with abundance declining from north to south. Offshore, it occurs from Maine through North Carolina. Three stock units have been identified based on regional differences in life history parameters. They are the Gulf of Maine (GOM), Georges Bank (GBK), and Southern New England (SNE).
Reproduction and growth are linked to the molting cycle. Lobsters periodically shed their shell to allow their body size to increase and mating to occur. Sperm is deposited in recently molted females and stored internally until extrusion, which can extend for two years. When extruded, the eggs are fertilized and attached to the underside of the female, where they are carried for 9 to 11 months before hatching. Eggs hatch from mid-May to mid-June. Lobster larvae transition through 5 stages. For the first 4 stages larvae are planktonic, swimming at or near the water surface. At the fifth larval stage, juveniles sink to the ocean floor where they remain for the rest of their lifetime. Lobsters reach market size in about four to nine years, depending on water temperature and other biological factors.
American lobster is one of the most valuable commercial fisheries along the Atlantic coast, with an ex-vessel value of $430 million in 2012. The fishery has seen an incredible expansion in effort and landings since the late 1940s and early 1950s, when landings varied around 25 million pounds. Over The past two decades, coastwide landings have increased substantially, rising to 57 million pounds in 1993 to a peak of 150 million pounds in 2012.
A majority (~90%) of the commercial landings of lobster are caught in state waters (0-3 miles from shore), with Maine and Massachusetts accounting for 84% and 10% of the landings, respectively. Lobster pots are the main method of harvest, although gill nets, otter trawls and dredges also account for some landings. In 2012, approximately 94% of the coastwide landings have come from GOM. SNE and GBK each accounted about 3% of the landings.
Lobster is recreationally caught by anglers using lobster pots or by hand while SCUBA diving. However, the magnitude of these recreational landings is unknown.
MA lobsterman, Dave Casoni, harvesting the day's catch. Photo credit: MA DMF.
The 2009 peer-reviewed stock assessment report presents a mixed picture of lobster abundance throughout its US range. The report indicates record high abundance and recruitment (number of lobsters entering the fishery) throughout most of GOM and GBK. The SNE stock is in poor condition with continued low abundance and recruitment. Further analysis on the SNE stock has found that the reproductive potential and abundance of the SNE stock is continuing to fall lower than data presented in the 2009 assessment. The SNE stock is critically depleted and abundance indices are at all time lows.
Based on biological reference points, adopted in 2010, GOM and GBK stocks are in favorable condition, with exploitation at a moderate level in the GOM and favorable in GBK. The SNE is in an unfavorable condition, requiring Board action to rebuild the stock and address the low levels of recruitment. The next benchmark stock assessment will be conducted in September 2014, with the peer review scheduled for early 2015.
American lobster is managed under Amendment 3 to the Interstate Fishery Management Plan for American Lobster, as well as Addenda I through XXI to the same plan. The main goal of the American lobster management plan is to increase egg production in females. Amendment 3 establishes seven lobster management areas: Inshore and offshore GOM (Area 1), Inshore SNE (Area 2), Offshore Waters (Area 3), Inshore and offshore Northern Mid-Atlantic (Area 4), Inshore and offshore Southern Mid-Atlantic (Area 5), New York and Connecticut State Waters (Area 6), and Outer Cape Cod. Lobster Conservation Management Teams (LCMTs), composed of industry representatives, were formed for each management area. The LCMTs are charged with advising the Lobster Board and recommending changes to the management plan within their areas. The commercial fishery is primarily controlled through minimum/maximum size limits, trap limits and v-notching of egg-bearing females.
Given the critically depleted condition of the SNE stock, the American Lobster Management Board has approved Addenda XVII - XXI, which implement a suite of measures to reduce exploitation and allow the SNE stock to rebuild. These measures include a v-notching program, trap reductions, closed seasons for certain areas, and a trap consolidation/transferability program.