Research Document - 2011/076
Assessing the status of the cod (Gadus morhua) stock in NAFO Subdivision 3Ps in 2010
By B.P. Healey, E.F. Murphy, J. Brattey, N.G. Cadigan, M.J. Morgan, D. Maddock Parsons, D. Power, R. Rideout, E. Colbourne, and J.C. Mahé
Abstract
The status of the cod stock in Subdiv. 3Ps was assessed during a regional assessment process held during October of 2010. Stock status was updated based upon information collected up to spring 2010. Principal sources of information available for the assessments were: reported landings from commercial fisheries, oceanographic data, a time series of abundance and biomass indices from Canadian winter/spring research vessel bottom trawl surveys, inshore sentinel surveys, science logbooks from vessels <35 ft, and tagging studies. The total allowable catch (TAC) for the 2009-10 fishing season was set at 11,500 t. Total landings for the 2009-10 management year (April 1-March 31) were 8,892 t or just 77 % of the TAC. This is atypical, and industry participants indicated this discrepancy was primarily due to a large reduction in prices, additional market considerations and some reduction in fish availability offshore. The 2010-11 fishery was still in progress at the time of the RAP with provisional landings totaling of 5,600 t. The removals through recreational fishing are unknown since 2007, but based on previous estimates are thought to be a small fraction (~1 %) of the commercial landings.
A complex of stock components are exploited in Subdiv. 3Ps. Thus the impact of fishing at specific TAC levels on all components cannot be quantified. However, the DFO RV survey covers most of the stock, and it is thought that survey trends broadly reflect overall stock trends.
The abundance index from the 2010 DFO RV spring survey was 27 % higher than that of 2009, and is now above the time-series (1983-2010) average. This increase is largely due to the relatively abundant 2006 year-class. The biomass index for 2010, however, remains similar to the 2009 value, less than the time-series average. The 2006 year-class is estimated to be as strong as the 1997 and 1998 year-classes, which contributed to stock growth and supported commercial fisheries for several years. Catch rates from inshore sentinel surveys and logbooks for vessels <35 ft suggest stability.
Spawning stock biomass (SSB) estimated from a survey based cohort model decreased in recent years and in 2008 and 2009 there was a probability of 0.59 and 0.75, respectively, that SSB was below the limit reference point (LRP). The SSB in 2010 is estimated to be above the LRP, although the probability of being below the LRP is 0.37. A one year projection to 2011 indicated that survey SSB will increase if total mortality rates are similar to current values (i.e., within ±20 %), and that the probability of being below the LRP in 2011 is low (0.04 to 0.17).
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