Since 2017, industry-supported scientific surveys targeting Atlantic halibut (Hippoglossus hippoglossus) have been conducted in the Gulf of St. Lawrence and parts of the estuary. The primary objective of the project is to gather data on the species' abundance, distribution, and biological characteristics. To achieve this, a stratified random longline survey is carried out, during which Atlantic halibut of all sizes are measured and tagged using two spaghetti tags. Beginning in 2024, tissue samples from the pelvic fin of each individual were also collected for genetic analysis.

Atlantic halibut are captured using longlines equipped with 500 circle hooks. While the length of the leaders varies among vessels, the spacing between leaders ranges from 3.6 to 5.5 meters. Fork length is measured for each individual of commercial species caught - such as Atlantic halibut, cod, redfish, and Greenland halibut (turbot). Measurements are also occasionally taken for non-commercial species.

This publication includes the file Donnees_Releve_Fletan_Halibut_Survey_Data, which provides information associated with each sampled station. It also contains the number of Atlantic halibut, cod, redfish and Greenland halibut (turbot) caught at each station. It is important to note that only beginning in 2019 were all commercial species systematically measured. The "NA" values in 2017–2018 do not indicate that no individuals were caught, but rather that they were not measured systematically.

Note: There are missing data in various columns of the dataset - use data with caution - if you have any questions please contact the data management team gddaiss-dmsaisb@dfo-mpo.gc.ca.