Science Advisory Report  2013/029

American lobster, Homarus americanus, stock status in the southern Gulf of St. Lawrence: LFA 23, 24, 25, 26a and 26b

Summary

• Preliminary lobster landings in the southern Gulf of St. Lawrence in 2011 of 18,964 t are 73% above the long-term median value (10,933 t) for the period 1947 to 2011. Although part of the recent increase in landings could be attributed to an increase in egg production, favorable environmental factors are thought to have favoured strong lobster recruitment resulting in very high catches over most of the northern portion of its range.
• Stock status of lobster within the five Lobster Fishing Areas located in the Gulf Region is assessed using fishery-dependent and fishery-independent data.
• Fishing pressure indicators include estimates of exploitation rates, the proportion of empty traps, and trends in nominal effort. Exploitation rates, where and when estimates were available, averaged 47% to 83% and have not declined in the past decade. Reduced proportions of empty traps, and reductions in nominal effort (licences and total trap allocations) are indicative of reduced fishing pressure on the stock, however, the effect of this reduction on lobster stocks and the fishery is not yet known.
• Lobsters in the southern Gulf of St. Lawrence continue to be in high abundance with recent landings above long-term medians or the highest of the time series. The only area with weak or negative trends is central Northumberland Strait (sub-regions 25S and 26AD).
• Based on fishery dependent indices, there is an increase in the abundance of commercially exploitable lobster and in the abundance of berried females in all Lobster Fishing Areas of the southern Gulf with the exception of sub-region 26AD (eastern central Northumberland Strait).
• Where fisheries independent indices are available, an increase in abundance of commercially exploitable lobster is noted, with the exception of sub-region 26AD.
• There are no estimates of total biomass of lobster in the southern Gulf of St. Lawrence, in terms of biomass available to the fishery or biomass of reproductive females. In the absence of these measures, landings are used as a proxy of biomass and a berried female index from at-sea sampling as a measure of reproductive potential. The validity of these proxies has not been demonstrated.
• There is continued concern regarding the accuracy of the catch data derived from the official catch system and the delay of availability of these data and there are uncertainties in the amount of non-recorded lobster. Only preliminary landings data for 2011 were available for this assessment.
• Several indicators reviewed in this assessment can be used to assess the status of stocks in the intervening years of the multi-year assessment and management cycles.

This Science Advisory Report is from the regional peer review meeting of February 26 to 28, 2013 on the assessment of the status of the lobster (Homarus americanus) and rock crab (Cancer irroratus) stocks of the southern Gulf of St. Lawrence. Additional publications from this meeting will be posted on the Fisheries and Oceans Canada (DFO) Science Advisory Schedule as they become available.

Complete document (PDF, 803 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.