Description

Fisheries and Oceans Canada (DFO) conducts an annual summer multidisciplinary scientific survey with a bottom trawl in the Estuary and the northern Gulf of St. Lawrence since 1984. Over the years this survey has been conducted on four vessels: the MV Lady Hammond (1984-1990), the CCGS Alfred Needler (1990-2005), the CCGS Teleost (2004-2022) and the CCGS Cabot (2022-present). It is important to note that the objectives, the methods used and the identification of the species during these surveys have improved over time in response to DFO requests and mandates. The data are therefore not directly comparable between these surveys. However, comparative analyses have been carried out between vessels, and conversion factors are available on request for a number of species. The specificities of the missions onboard the CCGS Teleost are described below. Objectives: 1. Assess groundfish and northern shrimp population abundance and condition 2. Assess environmental conditions 3. Conduct a biodiversity inventory of benthic and demersal megafauna 4. Assess phytoplankton and mesozooplankton abundance 5. Monitor the pelagic ecosystem 6. Inventory marine mammals populations 7. Inventory seabirds populations 8. Collect samples for various research projects Survey description The survey covers the Estuary and the northern Gulf of St. Lawrence, that is the divisions 4R, 4S and the northern part of division 4T of the Northwest Atlantic Fisheries Organization (NAFO). Since 2008, coverage of division 4T has been increased in the upstream part of the Lower Estuary in order to sample the depths between 37 and 183 m. A stratified random sampling strategy is used for this survey and the area of the study area is 118,587 km². The fishing gear used on the CCGS Teleost is a four-sided Campelen 1800 shrimp trawl equipped with a Rockhopper footgear (“bicycle”). The trawl lengthening and codend are equipped with a 12.7-mm knotless nylon lining. Standard trawling tows last 15 minutes, starting from the time the trawl touches the sea floor. The target towing speed is 3 knots. Data For each fishing tow, the catch is sorted and weighed by taxa; individuals are then counted and biological data are collected on a subsample. For fish, crab and squid, size and weight are measured by individual and, for some species, sex, gonad maturity, and the weight of certain organs (stomach, liver, gonads) are also evaluated. The soft rays of the anal fin are counted for redfish, and the otoliths are sampled for several species such as Atlantic cod, Atlantic halibut, Greenland halibut, and witch flounder. A roughly 2-kg shrimp sample is sorted and weighed by species (and by stage of maturity for northern shrimp). The shrimps are measured individually. The other invertebrates are counted (no individual measurements) and photographed. The biological data are divided into 3 files: a “Stations” file containing set information, a “Catches” file containing catches per set for all species caught and a “Carbio” file containing biological and morphometric measurements per individual all species measured except shrimps. The columns source_info, no_survey, nbpc and station_number serve as a common key linking the three datasets. To further link the “Captures” and the “Carbio” files to the species level (for fish and certain invertebrate species), use the columns source_info, no_survey, nbpc, station_number, strap_code, and category. Further shrimp biological and morphometric data are available but are not presented here in order to simplify data presentation. For access to the complete information, please contact the data management team (gddaiss-dmsaisb@dfo-mpo.gc.ca). The latest published data is preliminary and will be updated at the end of January of the following year. It's important to note that this is raw data. Only set considered successful are retained. In each set, all species are kept, with a few exceptions. For more information please contact the data management team (gddaiss-dmsaisb@dfo-mpo.gc.ca).

Resources

Name	Format	Description	Link
Data dictionary	CSV		https://api-proxy.edh-cde.dfo-mpo.gc.ca/catalogue/records/40381c35-4849-4f17-a8f3-707aa6a53a9d/attachments/Dictionnaire_donn%C3%A9es_Data_dictionary_teleost.csv
Data Teleost	CSV		https://api-proxy.edh-cde.dfo-mpo.gc.ca/catalogue/records/40381c35-4849-4f17-a8f3-707aa6a53a9d/attachments/Donnees_data_teleost.zip
Teleost Map data	Ersi REST		https://egisp.dfo-mpo.gc.ca/arcgis/rest/services/open_data_donnees_ouvertes/evaluation_groundfish_shrimp_survey_estuary_ngulf_st_lawrence_teleost/MapServer
Teleost Map data	Ersi REST		https://egisp.dfo-mpo.gc.ca/arcgis/rest/services/open_data_donnees_ouvertes/evaluation_groundfish_shrimp_survey_estuary_ngulf_st_lawrence_teleost/MapServer
Bottom water temperature and salinity in the Estuary and Gulf of St. Lawrence	HTML		https://open.canada.ca/data/en/dataset/10987662-c496-4ba8-a6b9-21cb5a134da2
Bottom water pH in the Estuary and Gulf of St.Lawrence	HTML		https://open.canada.ca/data/en/dataset/15c36c35-bb63-425e-9753-12704d310844
Demersal fish group richness in the Estuary and Gulf of St. Lawrence	HTML		https://open.canada.ca/data/en/dataset/182acf27-3ca0-49bb-9a68-50dbd8657331
Pelagic fish group richness in the Estuary and Gulf of St. Lawrence	HTML		https://open.canada.ca/data/en/dataset/267e20aa-97e8-43da-8c23-1234376938bc
Pelagic fish total biomass in the Estuary and Gulf of St.Lawrence	HTML		https://open.canada.ca/data/en/dataset/308b7792-a075-4b43-a68f-37bf35d76a9f
Summer surface conditions – Multidisciplinary surveys	HTML		https://open.canada.ca/data/en/dataset/6ac8d5f2-6a3d-4313-8785-881b2ac2ad24
Demersal fish total biomass in the Estuary and Gulf of St. Lawrence	HTML		https://open.canada.ca/data/en/dataset/9b1d5058-81a9-420c-afb9-69791b06e35a
Demersal fish species abondance in the Esturay and Gulf of St. Lawrence between 2008 and 2017	HTML		https://open.canada.ca/data/en/dataset/d4ec2d6b-f4bc-4c6c-b866-b26e507a3b76
Pelagic fish species abondance in the Esturay and Gulf of St. Lawrence between 2008 and 2017	HTML		https://open.canada.ca/data/en/dataset/f1fc359c-0ed1-4045-a421-adef2497b68d
Deep water dissolved oxygen in the Estuary and Gulf of St. Lawrence	HTML		https://open.canada.ca/data/en/dataset/fb362c48-fe21-4e4d-abee-cf7ef92b475d
Preliminary results from the groundfish and shrimp multidisciplinary survey in August 2018 in the Estuary and northern Gulf of St. Lawrence	PDF		https://www.dfo-mpo.gc.ca/csas-sccs/Publications/ResDocs-DocRech/2019/2019_037-fra.html

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