Assessment of softshell clam stocks in Quebec coastal waters

Abstract

Commercial landings in Quebec have been at historically low levels since 2010. In 2022, landings (10.8 t) reached the lowest level since 1917, while they had peaked in 2000 (1,207 t). In 2022, 91.7% of the commercial landings were from the North Shore (9.9 t), mainly from Pointe-aux-Outardes Ouest (9.4 t, sub-area 1B). Landings were significantly lower in sub area 1A (0.5 t). In the Magdalen Islands, landings constituted only 0.9 t, or 8.3% of the total landings in Quebec. Total allowable catches (TACs) are applied in some areas; however, they were not fully utilized due to low fishing effort. Fishing effort has followed the same trend as landings, and has also been very low since 2010. Effort has declined from a high of 12,142 vendor-days in 2002 to 1,111 in 2009. In 2022, there were 198 vendor-days for all of Quebec which represents one of the lowest values since 2002. The decline in effort is explained by the decreased market demands for clams. The sharp decline in effort has resulted in a high variability in the catch per unit effort (CPUE) in recent years and makes it difficult to detect trends in recently exploited areas. In 2022, the average size of landed clams ranged from 65 to 75 mm on the North Shore and from 56 to 70 mm in the Magdalen Islands. Generally, there is an upward trend in the average size of clams on the Upper North Shore. Additionally, the proportion of sub-legal size (< 51 mm) clams in landings was less than 3% in all exploited shellfish areas. Recreational fishing, an activity valued by coastal communities, is permitted on a major portion of Quebec’s coastline. While the volume of recreational harvests remains unknown, it may be significant in some areas. It would be important to quantify the effort, removals and size structure of clams harvested during this activity. In the absence of an inventory of exploited areas since 2019 and given the low landings, it is not possible to provide an advice on the status of shellfish areas for the upcoming seasons. However, with the recent low commercial fishing effort, there is no concern for the conservation of harvested beds.