Science Advisory Report  2009/017

Assessment of lobster stocks of the Gaspé
(LFAs 19, 20 and 21) in 2008

Summary

• In the Gaspé, between 2006 and 2008, the abundance indicators were on the whole similar to those observed in 2005. The 2008 landings were however 11.5 % higher compared to 2005, reaching 785 tons. They were slightly (2.6 %) below the 1984-2007 average. The majority of the 2008 landings came from LFA 20 (94 %), while LFAs 19 and 21 comprised 3.6 % and 2.4 % of the landings respectively. The mean catch per unit effort (CPUE) in LFA 20 remained somewhat stable between 2006 and 2008 at 0.4 lobster/trap and 0,25 kg/trap, and comparable to 2005. CPUE was 26% (in number) and 9% (in weight) below the 1986-2007 average. A reduction in fishing effort, unfavourable climatic factors and a reduced catchability could partly explain the decrease. In LFA 19, from 2006 to 2008, the abundance indicators were comparable to the previous years. CPUEs in this LFA (0.5 kg/trap in 2008) are among the highest in the Gaspé, although very variable from year to year.
• In LFA 20, the demographic indicators showed that the average size of lobster caught has been stable since 2004 at a level about 6-7 mm larger (carapace length, CL) than the mean size recorded prior to the increase of the minimum legal size. The mean weight is of about 25% higher. Mean sizes observed from 2006 to 2008 were comparable to 2005. During the last three years, the sex-ratio remained in favour of males overall and seems appropriate for reproduction. The proportion of jumbo size lobster (≥ 127 mm CL) remained low (< 1%) in LFA 20. LFA 19 is different and the size structure is more spread out. The porportion of jumbos reached 6.5% in 2008.
• The fishing pressure indicators estimated for 2005 to 2007 in LFA 20 varied from 77 to 84%, which is slightly lower compared to 2004. However, fishing mortality for the portion of the population ≥ 76 mm CL dropped as a result of the increase in the minimum legal size. Exploitation rate is much lower in LFA 19 than elsewhere in the Gaspé.
• The stock productivity indicators remained positive from 2006 to 2008. The abundance of berried females in LFA 20 has remained higher than prior to the increase of the minimum legal size. As in 2005, egg production estimates for 2006-2008 were higher by a factor of around two compared to those prior to the increase of the minimum legal size. In 2008, the number of multiparous females was slightly higher than in 2005 but their relative contribution to the total egg production was similar to 1996. Recruitment indices in LFA 20 were positive in 2008. Prerecruits appeared more abundant than in 2007 in many sub-areas. However, because the data series is short it is ot possible to forecast the recruitment to the fishery for 2009 or 2010.
• Despite the efforts and some positive signs, improvements to the size structure of the stocks appear necessary in LFA 20. This will help reduce the dependence of the fishery on the annual recruitment and will also help increase the proportion of multiparous females in the population and ensure their reproductive success by maintaining suitable sex-ratios, according to the recommendations by the FRCC (2007). Thus, it is important to continue the program for reducing the fishing effort introduced in 2006. In a long term outlook, it is important to identify some biological reference points in developing a formal precautionary approach for this fishery.
• In LFA 21B, fishing effort remained under historic levels, as recommended. Catch rates (CPUE) during the fall fishery remained stable since 2004. It is recommended to maintain the minimum legal size at 82 mm CL and to continue the limitation of the annual fishing effort so that it does not exceed the historical levels for this area.

Complete document (PDF, 313 KB)

Accessibility Notice

This document is available in PDF format. If the document is not accessible to you, please contact the Secretariat to obtain another appropriate format, such as regular print, large print, Braille or audio version.