Scientific surveys on the snow crab (Chionoecetes opilio) in the estuary and northern Gulf of St. Lawrence

Since 1992, scientific surveys have been conducted annually alternately, in the estuary and the North of the Gulf of Saint Lawrence. These surveys allow DFO to monitor the population and ecosystem of the snow crab and thus understand the state of the stock and the renewal of the species.

Beam trawl hauls following a systematic sampling take place every 2 years in the estuary and in the Lower North Shore. In the estuary (zone 17), a sampling of 94 stations is carried out. In the Lower North Shore (zone 13 and 14), 60 regular stations are usually sampled and 35 exploratory stations are distributed between Baie Johan Bettz and Kegaska (zone 15 and 16) but also on the south shore of zone 13 near Newfoundland. At each station, a fishing haul of 5 to 10 minutes is carried out. The harvested crabs are measured (cephalothorax width), sexed and counted. The state of the shell, sexual maturity and egg development stages are also assessed. The number of crabs caught, classified according to different size categories, allows estimating densities and thus monitoring the state and renewal of the snow crab population in the different fishing areas.

This dataset on the snow crab (Chionoecetes opilio) contains abundance and density data of crabs under different size classes as well as geographical and bathymetric variables by station. The dataset covers the period from 1992 to the present and is updated each year. A cleaning of aberrant data has been carried out.

For certain time periods, associated species are identified and semi-quantitatively counted directly on the sorting table, and the results are presented in the following publications:

• https://open.canada.ca/data/en/dataset/8fbd81a4-ce4a-40e3-81f6-e2a5c44955de

• https://open.canada.ca/data/en/dataset/268bf29e-b9d6-4267-bc86-230f4edfb80b

• https://open.canada.ca/data/en/dataset/97dac757-2ef6-4144-b7d9-a0d8d51f8319