Science Advisory Report  2013/016

Assessment of Atlantic surfclam in the coastal waters of the Îles-de-la-Madeleine in 2012

Summary

• The Atlantic surfclam fishery in the Îles-de-la-Madeleine is conducted with hydraulic dredges in sub-areas 5A1 and 5B or using hand tools, on foot or while diving, in about 10 shellfish sectors located in lagoons or near coasts.

Hydraulic dredge fishery

• In sub-area 5A1 in 2012, the total allowable catch (TAC) was 125 tons (t) and landings totalled 134 t with a fishing effort of 21 days, which is less than 58% of the average effort during the reference period. In 5B1, the TAC was 100 t in 2012 and landings totalled 103 t with a fishing effort of 20 days.
• CPUE has been increasing in 5A1 since 2008, and reached a record high of 314 kg per hour/meter (kg/hm) in 2012. In 5B1, annual CPUE has been relatively stable since 2009. In 2012, CPUE was 275 kg/hm, which was higher than the reference average.
• Over the past three years, the average size of landed surfclam has been the same or greater than the reference average in sub-areas 5A1 and 5B1.
• The shift in fishing effort to new portions of surfclam beds from one year to another resulted in good yields and stable size structures.
• From 2010 to 2012, the proportion of known beds dredged annually was 3% in 5A1 and 13% in 5B1.
• Given that the fishery indicators were positive in 5A1 and that the proportion of the surface dredged was low, the TAC could be increased to 10% for 2013, as long as the annual fishing effort is limited to 50 days. Although the various indicators were relatively stable in 5B1, a large proportion of beds are dredged every year. As a result, the same TAC is recommended and fishing effort must be limited to 30 days.
• Sub-area 5A2 has not been fished since 2002, and fishing effort has been sporadic and low in sub-area 5B2. It is therefore impossible to comment on the status of the resource in these two sub-areas.

Hand digging

• The available information on hand digging, either on foot or while diving, is limited. This type of harvesting is very popular and well-developed. The average known annual landings from commercial hand digging is about 22 t; however, this value is underestimated and the amount of surfclam harvested recreationally is unknown.
• The available logbooks show that since 2010, the annual CPUE calculated from commercial harvesting on foot or while diving has been under the respective reference averages.
• The area of three hand harvested beds was determined in 2012. These beds are nearly all accessible on foot. The surfclam density of two of these beds, located in the Grande Entrée lagoon, is lower than that observed in 2007, which suggests a high fishing pressure.
• Given this information and the lack of knowledge of the contribution of beds accessible on foot to the recruitment to the Atlantic surfclam population in the Îles-de-la-Madeleine, it is recommended that hand harvesting be limited significantly.

This Science Advisory Report is from the meeting held on February 7, 2013 for the Assessment of Atlantic surfclam in the coastal waters of the Îles-de-la-Madeleine. Additional publications arising from this meeting will be posted as they become available on the Fisheries and Oceans Canada Science Advisory Schedule.

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