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Canadian Science Advisory Secretariat
Research Document - 2006/010
Stock status and indicators for the lobster fishery in Lobster Fishing Area 34
By Pezzack, D.S., J. Tremblay, R. Claytor, C.M. Frail and S. Smith
Abstract
Lobster Fishing Area (LFA) 34, off Southwest Nova Scotia encompasses 21,000km2 and has the highest landings of any LFA in Canada, accounting for 40% of Canadian landings and 23% of the world landings of Homarus sp. The fishery is undertaken by 937 Category A vessel based licenses and 30 Commercial Communal based licences (First Nations). The fishery is managed by input controls including a minimum carapace length (CL), prohibition on landing berried females, limited entry, a season between the last Monday in November through to May 31st, and a trap limit of 375 from November to March and 400 from March to May. This assessment is the first time indicators have been used to assess this fishery. Abundance indicators for legal size lobster which include landings, catch rate and scallop survey data are primarily positive. Landings in LFA 34 as a whole continue to be above long-term means but peaked in the 2001-02 season. Landings in sub-areas of LFA 34 ("Grid Groups") generally followed the pattern of the LFA as a whole. A notable exception was in a traditional nearshore ground (Grid Group 2a, Lobster Bay) which has declined 20% from the mean of the reference period (1998-99 to 1999-00) due to a shift in fishing effort away from this area (see below). Catch rates (CPUE) based on Lobster Catch and Settlement Reports (LFA 34 log books) throughout LFA 34 and on Fishermen and Scientist Research Society (FSRS) data (Grid Groups 2a and 2b) were also generally higher relative to the reference period but peaked between 2002-03 and 2003-04 depending on Grid Group. Fishing pressure indicators showed either increased pressure or no change. A shift in effort away from traditional nearshore grounds is indicated by a decline in numbers of trap hauls in the nearshore Grid Groups 1 and 2a and an increase in number of trap hauls in all other Grid Groups. The increase in fishing pressure in midshore and offshore portions of LFA 34 raises a conservation concern because these grounds have historically supported larger lobsters. Relative to the reference period (1998-2000), the stock is still fished at high levels with estimates for exploitation in nearshore areas (2a and 2b) on the order of 70% and higher. Production indicators showed either no changes or were positive in relation to the reference period. Pre-recruit abundance in a nearshore portion of LFA 34 (Grid Groups 2a and 2b) in fall, based on CPUE in FSRS traps, continues to be high but has trended downwards in the last one to two years to be at the level of the reference period. The limited number of indicators for berried females shows no change from the reference period. An ecosystem indicator (mean ocean bottom temperatures) fell by about 2.5°C from 1999-00 to 2003-04 and recovered by 1°C in 2004-05.
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