Research Document - 2008/033
Scallop fishing area 29: Stock status and update for 2008
By S.J. Smith, M.J. Lundy, J. Tremblay, C. Frail and S. Rowe
A total of 246 t of scallop meats were landed in SFA 29 against a TAC of 250 t in 2007. The quotas for Subareas C and D were exceeded while landings did not reach the TAC in Subareas A and B. Commercial catch rates and survey indices for commercial size scallops (≥ 100 mm) indicate little change in stock status in 2007 compared to 2006. Catches of scallops in the 2007 survey with shell heights less than 50 mm were above average throughout the SFA 29 area with the higher densities in the till/silt bottom type in Subareas A and B. Abundance estimates of this size class are qualitative at best given the selectivity of the survey gear and the actual strength of these year classes (2005 and 2006) will need to be confirmed by the 2008 survey. Analysis of daily catch rate data using a depletion model indicated that the 2007 catch levels of 12 t for Subarea A resulted in a median exploitation rate of 0.54. This high rate may be more indicative of local conditions than the whole subarea as fishing was limited to just a few locations in A. The median exploitation rates for the other subareas were 0.21 for C, 0.16 for D and 0.13 for B. The balance between biomass gains through recruitment and growth, and losses due to mortality are not known for the SFA 29 area. Keeping exploitation in 2008 at levels in the range of the expected growth in biomass in Subareas B, C and D should result in small or negligible declines in population biomass. That is, catches for 2008 would be in the order of 65, 22, and 61 t in Subareas B, C and D, respectively. Applying the same rationale to Subarea A would result in a recommended catch of less than 1 t in Subarea A. Given the highest densities of the 2005 and 2006 year-class were observed in Subarea A, the fishery should be limited there to improve the survival of these young scallops. Observer coverage of the scallop fishery in SFA 29 was low in 2007 due to priorities being given to the coverage of other fisheries at the same time and no coverage of the East of Baccaro fleet due to contractual issues. Bycatch of lobster by the SFA 29 scallop fishery in 2007 was estimated at less than 0.1 % of the number of lobsters landed by the Lobster Fishing Area (LFA) 34 lobster fishery in the SFA 29 area. Estimated landings of other fish and invertebrate species based upon the observer data indicated that as seen in previous analyses crabs, skates, flounders and sculpins made up the largest proportion of the bycatch species.
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