Science Advisory Report  2015/033

Assessment of the Estuary and Northern Gulf of St. Lawrence (Areas 13 to 17, 12A, 12B, 12C and 16A) Snow Crab Stocks in 2014

Summary

• Stocks in the Middle and Lower North Shore of the Gulf of St. Lawrence (Areas 13, 14, 15, 16, 16A and 12C) had high commercial biomass despite a decrease in Areas 16 and 12C. Fishery recruitment throughout these areas is still high, but may decrease starting in 2016 or 2017. Conversely, the commercial biomass remains low in Area 17, but recruitment has started to recover. The commercial biomass in Areas 12A and 12B has diminished and recruitment during the next few years could depend on production in adjacent areas.
• The purpose of conservation is to maintain an adequate male reproductive biomass in order to ensure the recovery or maintenance of the population in a given area. Recommendations assume that the natural mortality rate will be the same in 2015 as in previous years.

Perspectives

Area 17

• The drop in the combined index suggests that 2015 catches should decrease compared to 2014:
1. A status quo in catches would lead to a high harvesting intensity, which would slow the rate of increase of the biomass available to the fishery;
2. A decrease of approximately 10% should lead to a moderate harvesting intensity and help the biomass available to the fishery increase more rapidly;
3. Any decrease greater than 10% would lead to an even more rapid increase in biomass available to the fishery and would reduce the risk of harvesting large quantities of white crab in 2016.
• Any additional measures for protecting white crab would benefit the stock.

Area 16

• The drop in the combined index suggests that 2015 catches should decrease compared to 2014:
1. Too low a decrease in catches would lead to a high harvesting intensity and possibly to a rapid decrease in biomass available to the fishery starting in 2016;
2. It is unlikely that a decrease of approximately 20% would lead to an excessively high harvesting intensity and would moderate the expected short- and medium-term decline in stocks;
3. Any decrease greater than 20% could lead to the maintenance of a substantial biomass available to the fishery over a longer period of time.

Area 15

• The combined index suggests that it is possible to maintain 2015 catches at their 2014 levels:
1. An increase in catches greater than 10% would lead to a high harvesting intensity and could reduce the biomass available to the fishery in 2016;
2. A status quo would likely not entail an excessively high harvesting intensity and would moderate the effects of lower expected recruitment in the medium term;
3. Any decrease in catches could lead to maintenance of a substantial biomass available to the fishery over a longer period of time.

Areas 14 and 13

• The rise in the combined index suggests that it is possible to increase 2015 catches compared to 2014 levels:
1. An increase in catches greater the 25% would lead to a high harvesting intensity and could reduce the biomass available to the fishery in 2016;
2. It is unlikely that an increase of approximately 20% would lead to an excessively high harvesting intensity and would moderate the effect of lower expected recruitment in the medium term;
3. An increase of less than 15% could lead to the maintenance of a substantial biomass available to the fishery over a longer period of time.
• For Area 13, it will be necessary to foster a better distribution of the fishing effort between the northern and southern parts of the area.

Area 12A

• The drop in the combined index suggests that 2015 catches should decrease compared to 2013 and 2014:
1. Too low a decrease in catches could lead to a high harvesting intensity and possibly to a decrease in the biomass available to the fishery in 2016;
2. A decrease of approximately 20% should lead to a moderate harvesting intensity and help to maintain the biomass available to the fishery;
3. A larger decrease would foster an increase in biomass available to the fishery in the short and medium term.

Area 12B

• The drop in the combined index, despite some uncertainty, suggests that 2015 catches should decrease considerably compared to 2014:
1. Too low a decrease in catches would lead to a high harvesting intensity and to a sharp decrease in the biomass available to the fishery in 2016;
2. A decrease of approximately 25% could lead to a moderate harvesting intensity, which would reduce the expected short- and medium-term decline in stocks;
3. An even larger decrease would be consistent with biomass indicators and could stabilize the biomass available to the fishery in the short and medium term.

Area 12C

• The drop in the combined index suggests that 2015 catches should decrease compared to 2014:
1. A status quo in catches would lead to a high harvesting intensity and possibly to a decrease in the biomass available to the fishery in 2016;
2. It is unlikely that a decrease of approximately 10% would lead to an excessively high harvesting intensity and would moderate the effect of lower expected recruitment in the medium term;
3. Any decrease greater than 15% could lead to the maintenance of a substantial biomass available to the fishery over a longer period of time.

Area 16A

• The rise in the combined index suggests that it is possible to slightly increase 2015 catches compared with 2014:
1. An increase in catches greater than 15% would lead to a high harvesting intensity and could decrease the biomass available to the fishery in 2016;
2. It is unlikely that an increase of approximately 10% would lead to an excessively high harvesting intensity and could foster maintenance of the biomass available to the fishery;
3. A status quo or a decrease in catches could lead to maintenance of a substantial biomass available to the fishery over a longer period of time.

This Science Advisory Report is from the February 24 and 25, 2015 meeting on the Assessment of the Estuary and northern Gulf of St. Lawrence Snow Crab stocks. Additional publications from this meeting will be posted on the Fisheries and Oceans Canada Science Advisory Schedule as they become available.

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