Évaluation des stocks de concombre de mer des eaux côtières du Québec en 2023

Abstract

The sea cucumber dredge fishery in Quebec began in 2008 and remained in the exploratory stage in fishing areas 3, B, and C in 2023. Mean annual landings during the 2021–2023 period totalled 879 t, 50% of which came from the Gaspé Peninsula’s north shore and 50% from the Mingan Archipelago. In 2022, dockside monitoring of the size structure of sea cucumbers based on eviscerated mass replaced the less reliable length-based measurements used for over a decade. Size at maturity based on eviscerated mass was determined for both male and female sea cucumbers in the Mingan Archipelago region (Fishing area 3) and could inform future management measures to protect the reproductive potential of the stock. Mingan Archipelago Fishing Area 3 Since 2018, the authorized fishing effort has been set at 120 days. From 2021 to 2023, mean annual landings were 442 t, which is comparable to those for the 2017–2020 period (466 t). Landings in 2023 were among the highest values in the time series. The fishing effort from 2021 to 2023 (77 days) was also consistent with the effort of 79 days from 2017 to 2020. The mean catch per unit effort (CPUE) in 2021–2023 was 128 kg/t·m, representing a slight increase compared with the mean of 118 kg/t·m from 2017 to 2020. Measurements of eviscerated mass taken in 2022 and 2023 indicated that the majority of landed sea cucumbers were mature individuals. Gaspé Peninsula Fishing Area B The total allowable catch (TAC) has been set at 325 t annually since 2017 and was fully used from 2021 to 2023 with mean annual landings of 322 t during that period. Annual fishing effort remained similar to the effort employed from 2017 to 2020. The mean CPUE from 2021 to 2023 was 135 kg/t·m, representing a slight increase from the mean of 125 kg/t·m from 2017 to 2020. Measurements of eviscerated masses taken in 2023 indicated that the majority of landed sea cucumbers were mature individuals. Fishing Area C The TAC has been set at 271.7 t every year since 2020 and was not fully exploited between 2021 and 2023 owing to socio-economic factors. Mean annual landings during that period were 64 t. Fishing effort declined by 70% compared with the effort from 2017 to 2020. The CPUE has been increasing in the past three years (2021–2023), with the mean CPUE during that period (64 kg/t·m) being slightly greater than that from 2017 to 2020 (56 kg/t·m). Measurements of eviscerated masses taken in 2023 indicated that the majority of landed sea cucumbers were mature individuals. Fishery-independent surveys In 2022, Fisheries and Oceans Canada (DFO) conducted a research survey in Fishing Area 3. From 2013 to 2023, MWIFMA carried out post-season surveys in Fishing Areas B and C. The DFO survey conducted in Fishing Area 3 revealed a decreasing gradient in sea cucumber densities from west to east in the study area. Individuals sampled at stations in the eastern portions of the study area also tended to show greater variability in mean eviscerated masses and a wider range of values than those sampled in the west. According to the results of the MWIFMA post-season survey from 2021 to 2023, sea cucumber abundance and biomass in Fishing Areas B and C were higher at sites that had not been dredged in more than four years compared with those that were actively fished. Perspectives for the 2024 to 2026 fishing seasons In Fishing Area 3, maintaining annual fishing efforts similar to those observed from 2021 to 2023 may be able to support similar yields over the next three years. In Fishing Area B, given the conservation measures implemented, including protected areas and depth restrictions, maintaining landings near the mean levels from 2021 to 2023 is not expected to significantly impact sea cucumber abundance across the area over the next three years. In Fishing Area C, the low volume of landings from 2021 to 2023 creates considerable uncertainty in the monitoring of the resource, and the current status of the sea cucumber population in this area is unclear. It is recommended that stock indicators continue to be monitored until the next assessment.