MA lobsterman, Dave Casoni, harvesting the day's catch. Photo credit: MA DMF.
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. Males deposit sperm in recently molted females who store it internally until extrusion, which can be delayed for up to 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. Females carrying eggs are often called “berried” females. Eggs hatch from mid-May to mid-June, and the new lobster larvae begin their 5 stage transition. Larvae are planktonic for the first 4 stages, 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.
Total U.S. landings in the fishery have steadily increased in the past 35 years. Up until the late 1970s, landings were relatively constant at about 30.87 million pounds. However by 2000, landings almost tripled to roughly 86 million pounds and by 2006 grew to 92.61 million pounds. Landings in 2013 were roughly 149.94 million pounds. These landings are primarily comprised of catch from inshore waters (0 to 12 nautical miles). GOM supports the largest fishery, constituting approximately 76% of the U.S. landings between 1981 and 2007 and accounting for approximately 87% of landings since 2002. Landings in the GOM were stable between 1981 and 1989, averaging 32.13 million pounds, and then increased dramatically from 42.34 million pounds (1990) to 141.12 million pounds (2013). Landings averaged 112.46 million pounds from 2008-2013. GBK constitutes a smaller portion of the U.S. fishery, with landings averaging 4.93 million pounds between 2008 and 2013. Like the GOM, landings were stable in the 1980s and then quickly doubled in the early 2000s to a high of 5.29 million pounds in 2005. Before 2011, SNE was the second largest fishery, accounting for 19% of the U.S. landings between 1981 and 2007; however, a sharp decline in the population has significantly reduced catch. Landings peaked in the 1990s, reaching a high of 21.91 million pounds in 1997. Since this time, landings have precipitously dropped to a low of 3.31 million pounds in 2013.
The 2015 American Lobster Benchmark Stock Assessment and Peer Review Report indicates the American lobster resource presents a mixed picture of stock status, with record high stock abundance and recruitment in the Gulf of Maine (GOM) and Georges Bank (GBK), and record low abundance and recruitment in Southern New England (SNE). The GOM/GBK stock is not overfished and not experiencing overfishing. GOM and GBK were previously assessed as separate stock units and are now combined into one stock unit due to evidence of seasonal migratory patterns and connectivity between the two areas. Conversely, the SNE stock is severely depleted with poor prospects of recovery, necessitating protection.
Gulf of Maine/Georges Bank
GOM/GBK stock abundance has increased since 1979 and at an accelerated pace since 2007. Recruitment and spawning stock abundance have remained high between 2008 and 2013. Current stock abundance is at all-time highs. Exploitation (fishing mortality) declined after 1979 until the mid-1990s and then remained stable with higher exploitation on males than females. Current exploitation rates remain on par with the 2008-2013 average.
Southern New England
SNE stock abundance increased from the early 1980s, peaked during the late 1990s, then declined steeply through the early 2000s to a record low in 2013. Both the assessment and peer review support the finding that the SNE stock is severely depleted. Declines in population abundance are most pronounced in the inshore portion of the stock where environmental conditions have remained unfavorable to lobsters since the late 1990s. The stock has collapsed and is undergoing recruitment failure. Despite attrition among the fleet and fewer traps fished for lobster, declines have continued. These declines are largely in response to adverse environmental conditions including increasing water temperatures over the last 15 years combined with sustained fishing mortality.
Declines in catch and fishery-independent survey indices in the offshore portion are evident as well; however they are not as severe. It is believed the offshore area of SNE depends on nearshore larval settlement and offshore migration as the source of recruits (e.g., young of the year lobsters). Therefore, unless fishing effort is curtailed, the offshore component will be in jeopardyin the future when the poor year classes fail to materialize offshore. The Peer Review Panel noted whilethe SNE stock is not experiencing overfishing based on the current reference points, these reference points were established “without considering the possibility that the stock could be at the lowest abundance level ever and the production of recruits in the inshore area (on which the offshore area depends) could be brought to an extremely low level. It is noted that pre-recruits are not measured in the offshore surveys, so the effects of recruitment failure in the inshore would not be seen in the offshore until years later when the lobsters become available to the fishery and surveys. Hence, by any reasonable standard, it is necessary to protect the offshore component of the stock until increased recruitment can be observed.”
Peer Review Panel Recommendations
For SNE, the Panel recommends close monitoring of stock status along with implementing measures to protect the remaining lobster resource in order to promote stock rebuilding. Stock indicators should be updated annually and reported to the Management Board for appropriate action. Given the good condition of the GOM/GBK stock, the Panel recommended stock indicators be monitored prior to the next benchmark assessment to detect signs of changing recruitment or other conditions.
American lobster is managed under Amendment 3 to the Interstate Fishery Management Plan (FMP) and its Addenda (I - XXIII). The goal of the American lobster management plan is to increase egg production. Amendment 3 establishes seven lobster conservation management areas (LCMAs): 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 (Area 7). Lobster Conservation Management Teams (LCMTs), composed of industry representatives, were formed for each management area. The LCMTs are charged with advising the American 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 Board approved Addenda XVII - XXII, 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. Throughout 2014, the American Lobster Board monitored the progress of the SNE LCMAs in achieving the required 10% reduction in exploitation in order to address rebuilding. Using landings as a proxy for exploitation, Technical Committee review of the implemented measures within SNE found LCMAs 2, 3 and 6 met the required reductions while LCMAs 4 and 5 did not. LCMA 4 submitted a proposal for a closed season from April 30 through May 31. This proposal was approved by the Management Board for implementation in both LCMAs 4 and 5.
In August 2015, the Board accepted both the stock assessment and peer review report for management use. In response to the continued poor status of the SNE stock, the Board initiated Draft Addendum XXV, with the goal of increasing egg production and decreasing fishing mortality. The Board will consider approving the document for public comment in February 2017.