American Lobster

The 2025 American Lobster Benchmark Stock Assessment and Peer Review Report describes contrasting conditions for the two American lobster stocks. The results indicate the Gulf of Maine and Georges Bank (GOM/GBK) stock is not depleted but has declined 34% since peak levels in 2018, and overfishing is occurring with recent exploitation just above the exploitation threshold. Conversely, the Southern New England (SNE) stock remains significantly depleted with record low abundances for all life stages in recent years.

Extensive research has highlighted the influence of the environment on American lobster life history and population dynamics, with temperature standing out as the primary driver among the critical environmental variables. Further, environmental conditions in the American lobster’s range are changing at some of the fastest rates in the world. Therefore, considering these environmental influences was a focal point of this stock assessment. Environmental data time series analyzed in this assessment included water temperatures at several fixed monitoring stations throughout the lobster’s range, average water temperatures over large areas such as those sampled by fishery-independent surveys, oceanographic processes affecting the environment, and other environmental indicators such as lobster prey abundance.

Environmental data were analyzed for regime shifts, which indicate a significant difference in the lobster’s environment and population dynamics from one time period to another. Regime shifts can impact a stock’s productivity, recruitment levels, and ability to support different levels of fishing pressure. Temperature time series were also analyzed to quantify the effect of temperature on the catchability of lobster in surveys and adjust annual survey estimates to account for temperature-driven changes in catchability.

Model-estimated abundance time series were also analyzed for shifts that may be attributed to changing environmental conditions and new baselines for stock productivity. The GOM/GBK stock shifted from a low abundance regime encompassing the early 1980s through 1995 to a moderate abundance regime from 1996-2008 and shifted once again to a high abundance regime from 2009-2018. The SNE stock shifted from a high abundance regime during the early 1980s through 2002 to a low abundance regime during 2003-2018. These results were used to structure trend-based reference points, consistent with the 2020 assessment.

Three reference points are used to characterize stock abundance. The abundance threshold is calculated as the average of the three highest abundance years during the low abundance regime. A stock abundance level below this threshold is considered significantly depleted and in danger of stock collapse. This was the only abundance reference point recommended for the SNE stock due to its record low abundance and low likelihood of exceeding this threshold in the near future. The abundance limit is calculated as the median abundance during the moderate abundance regime. Stock abundance that falls below this limit is considered depleted because the stock’s ability to replenish itself is diminished. The fishery/industry target is calculated as the 25th percentile of the abundance during the high abundance regime. In this case, when abundance falls below this target, the stock’s ability to replenish itself is not jeopardized, but it may indicate a degrading of economic conditions for the lobster fishery.

Two reference points are used to evaluate the fishing mortality condition of the stocks. The exploitation threshold is calculated as the 75th percentile of exploitation during the current abundance regime. The stock is considered to be experiencing overfishing if exploitation exceeds the exploitation threshold. The exploitation target is calculated as the 25th percentile of exploitation during the current abundance regime. The stock’s fishing mortality condition is considered favorable if the three-year average exploitation is less than or equal to the target. This overfishing reference point serves as an extra safeguard against sudden increases in exploitation that may not be explained by decreasing abundance.

Gulf of Maine/Georges Bank

Based on the abundance reference points, the GOM/GBK stock condition is favorable. The average abundance from 2021-2023 (202 million lobsters) has declined below the fishery/industry target (229 million lobsters) but remains above the abundance limit (143 million lobsters) and abundance threshold (89 million lobsters). Recruitment and spawning stock biomass estimates have declined in recent years from record highs.

The average exploitation from 2021-2023 (0.465) was just above the exploitation threshold (0.464), indicating overfishing is occurring. However, there are several caveats associated with the fishing mortality condition. Lobster fisheries are efficient at removing the harvestable part of the population that enters the fishery each year, so trends in landings closely track changes in population abundance. This relationship results in relatively stable exploitation during periods of consistent regulations, even during periods of rapid and consistent abundance increases and decreases. This complicates our understanding of the population’s response to fishing pressure. The stability of exploitation rates creates a narrow range of values separating favorable and unfavorable exploitation status, making the overfishing status determination sensitive to data and model uncertainty.

Model-free indicators of young-of-year (YOY) abundance have shown increases from lows in the 2010s, though remain neutral and below the positive levels observed in the 2000s. Abundance indicators of older lobsters generally showed similar results to the assessment model, with abundance declines from peaks since the last assessment. Spatial patterns within the stock appear to be playing an important role in driving the overall GOM/GBK stock dynamics as described by the model, with stronger declines evident in the inshore surveys and particularly the ME/NH survey compared to the offshore NEFSC survey. Similar patterns have occurred in exploitation with higher exploitation in the inshore area. and lower exploitation elsewhere. The new recruit-dependency indicators show inshore areas are highly dependent on incoming recruitment, which is a negative determination for exploitation. The encounter rate indicators show some contraction in the distribution within these inshore areas, likely related to declines in abundance. Landings and revenue fishery performance indicators show declining trends but remain positive.

Temperature data indicate that environmental conditions, particularly bottom water temperatures, remain positive in GOM/GBK and shell disease prevalence, although increasing in some areas, remains relatively low.

Given the rapid declines in abundance to levels below the fishery/industry target and the overfishing status, the assessment recommends the Management Board immediately initiate a Management Strategy Evaluation (MSE) to clearly define management objectives (across all stakeholders), better understand socioeconomic status and concerns, and identify potential management tools that might be supported by the industry and prevent further declines towards biological thresholds.

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 2023. The 2025 Assessment indicates the SNE stock is significantly depleted and overfishing is not occurring. The average abundance from 2021-2023 (6 million lobsters) was well below the abundance threshold (18 million lobsters). The average exploitation from 2021-2023 (0.258) fell below the exploitation threshold (0.286) and exploitation target (0.267).

Abundance indicators agree with model results and indicate declines to record low abundances for all life stages in recent years. The contraction of the SNE stock has continued and is now evident in offshore as well as inshore areas. Fishery performance indicators for SNE show continued declines in landings and revenue. Environmental conditions have worsened in the inshore region, and evidence suggests that the productivity of the stock is severely compromised with increased thermal stress and disease.

Although continued adverse environmental indicators suggest environmental conditions are major contributors to the poor abundance status, the assessment states significant management action would provide the best chance of stabilizing or improving stock abundance and reproductive capacity.

Peer Review Panel Recommendations

The Panel endorsed the stock assessment, finding that it meets and exceeds the standard for best scientific information available and provides a suitable foundation for management. The Panel commended the addition of socioeconomic data that provide insight into changes in the fishery and the considerable efforts to evaluate environmental impacts on the stock. Additionally, the Panel cautioned against placing too much emphasis on environmental effects and discounting the effects of fishing on the lobster populations.

The American lobster fishery is one of the most valuable fisheries along the Atlantic coast and has seen an incredible expansion in landings over the last 40 years. Between 1950 and 1975, landings were fairly stable around 30 million pounds; however, from 1976 to 2008 the average coastwide landings tripled, exceeding 98 million pounds in 2006. Landings continued to increase until reaching a high of 159 million pounds in 2016, but have been trending downward since then. In 2024, coastwide commercial landings were approximately 112.6 million pounds, a 7% decrease from 2023. The ex-vessel value for all lobster landings in 2024 was approximately $617 million dollars.

The vast majority of these landings came from GOM/GBK, where the stock abundance remains high compared to the time series average. The GOM fishery accounts for the largest portion of US lobster landings, averaging 82% of the annual landings since 1982, and is predominately carried out by small vessels in nearshore waters (< 12 miles from shore). The GBK fishery is considerably smaller, averaging 5% of the landings since 1982, and is predominantly carried out by larger vessels making multi-day trips to offshore waters. Total GOM/GBK annual landings increased from a stable period in the 1980s, averaging approximately 35.4 million pounds, through the 1990s and 2000s, exceeding 100 million pounds for the first time in 2009. Landings from 2012 through 2018 stabilized at record levels, averaging 145.7 million pounds. Landings have declined since the 2020 assessment, averaging 123.6 million pounds from 2019-2023.

Historically, the SNE fishery was predominately an inshore fishery. Landings peaked in 1997 at 21.8 million pounds and accounted for 26% of total US lobster landings. Following the peak, SNE landings have continuously declined to record lows, now accounting for only 1% of US landings. The fishery has also shifted to a predominantly offshore fishery as inshore abundance declined at a faster rate.

Lobster pots are the predominant commercial gear, with a small percentage of the landings caught by trawls. Lobster is also taken recreationally with pots and by hand while SCUBA diving. The overall quantity of recreational landings is unknown but is likely a negligible source of removals.