Science Advisory Report 2020/026

Assessment of American Lobster (Homarus Americanus) in Lobster Fishing Areas 27–32

Summary

• Lobster Fishing Areas (LFAs) 27–32 are managed separately and several LFAs have unique conservation measures, which include Minimum Legal Size (MLS), trap limits, maximum hoop sizes, maximum size or window sizes for landed females, and v‑notching.
• A spatial representation of Lobster landings indicates a recent increase in landings in some of the more easterly grids, while landings in other regions have remained more stable.
• Primary indicators are used to define stock status in relation to reference points. The primary indicator for describing stock status is the commercial Catch Per Unit Effort (CPUE). Exploitation, estimated using the Continuous Change in Ratio (CCIR) method, will be used as an indicator of fishing pressure.
• Secondary indicators represent time series trends that are tracked individually, without defined reference points. The secondary indicators are landings and total effort, as well as the recruitment trap sub-legal and legal catch rate series.
• Contextual indicators describe the biological processes that influence production as well as ecosystem and fishery performance.
• The primary indicators show positive signals for all LFAs. The CPUE is at its highest level in the time series for six of the seven LFAs. The primary indicator for exploitation, the CCIR models, are annually variable; however, the 3-year running median indicates exploitation has been relatively stable in all LFAs, where data is available.
• The current status of the lobster stocks within each LFA is within the Healthy Zone and exploitation is below the Removal Reference (RR).
• Within each LFA, contextual indicators support the determination, based on the primary and secondary indicators, that the stock is healthy.
• Within each LFA, the trend in landings is similar to the trend in CPUE as effort has remained fairly consistent in recent years.

LFA 27

• The trend in CPUE indicates that an increase in stock biomass occurred over a period when the MLS increased from 70 mm to 82.5 mm. The 3-year running median for CPUE for the 2018 season is 1.08 kg/trap haul (TH), which is above the Upper Stock Reference (USR, 0.27 kg/TH).
• The 3-year running median of CCIR exploitation for the 2018 season is 0.77, which is below the RR (0.84).
• The trend in the sub-legal size classes is similar to the trend in CPUE, with the largest increases in 2013, 2017, and 2018.

LFA 28

• The CPUE in LFA 28 for 2018 was 0.47 kg/TH, which is higher than the long-term mean of approximately 0.31 kg/TH and similar to the peaks observed in 2013–2015. The 3‑year running median value for CPUE for the 2018 season is 0.35 kg/TH, which is above the USR (0.25 kg/TH).
• Despite the deceased effort in 2017 and 2018, landings increased relative to 2016, but remained lower than the highs in 2014 and 2015.

LFA 29

• The 3-year running median value for CPUE for the 2018 season is 1.57 kg/TH, which is above the USR (0.22 kg/TH).
• The 3-year running median value of CCIR exploitation for the 2018 season is 0.71, which is below the RR (0.94).
• The trend in the legal and sub-legal size classes is similar to the trend in CPUE and landings, with an increase from 2003–2009, declines until 2013, and increasing thereafter. In 2018, the estimates of catch rates for both legal and sub-legal lobsters are the highest in the time series.

LFA 30

• The 3-year running median value for CPUE for the 2018 season is 2.78 kg/TH, which is above the USR (0.56 kg/TH).
• The 3-year running median value of CCIR exploitation for the 2018 season is 0.41, which is below the RR (0.77).
• The trend in the legal size classes is similar to the trend in CPUE. While there tends to be fewer sub-legal lobsters captured in recruitment traps, the trend is still consistent with other indicators.

LFA 31A

• The 3-year running median value for CPUE for the 2018 season is 1.20 kg/TH, which is  above the USR (0.31 kg/TH).
• The 3-year running median value of CCIR exploitation for the 2018 season is 0.70, which is below the RR (0.89).
• Catches of sub-legal size classes show a trend that is similar to the CPUE, but increases in sub-legal abundance are observed one year before they are observed in the commercial fishery, indicating that in this LFA the recruitment traps are a good indicator of recruitment.

LFA 31B

• The 3-year running median value for CPUE for the 2018 season is 1.28 kg/TH, which is above the USR (0.32 kg/TH).
• The 3-year running median value of CCIR exploitation for the 2018 season is 0.76, which is below the RR (0.82).
• The trend in the legal and sub-legal size classes is similar to the trend in CPUE and landings.

LFA 32

• The 3-year running median value for CPUE for the 2018 season 0.80 kg/TH, which is above the USR (0.29 kg/TH).
• The 3-year running median value of CCIR exploitation for the 2018 season is 0.74, which is below the RR (0.84).
• The trend in the legal and sub-legal size classes is similar to the trend in CPUE and landings.

This Science Advisory Report is from the February 11–12, 2019, LFA 27–32 Lobster Assessment. Additional publications from this meeting will be posted on the Fisheries and Oceans Canada (DFO) Science Advisory Schedule as they become available.

Science Advisory Report 2020/026 (PDF, 2,440 KB)

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