Fisheries and Oceans Canada (DFO) conducts an annual multidisciplinary scientific survey with a bottom trawl in the Estuary and the northern Gulf of St. Lawrence since 1978. Over the years this survey has been conducted on five vessels: the MV Gadus Atlantica (1978-1994), the MV Lady Hammond (1984-1990), the CCGS Alfred Needler (1990-2005), the CCGS Teleost (2004-2022) and the CCGS Cabot (2022-current). 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. The specificities of the missions onboard the CCGS Cabot are described below. Objectives: 1. Assess groundfish and northern shrimp population abundance and condition 2. Assess environmental conditions 3. Inventory species biodiversity 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. 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 Cabot 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 aimed towing speed is 3 knots. Data For each fishing tow, the catch is sorted and weighed by taxa; individual are then count and biological data are then collected on a subsample. For fish, crab and squid, size and weight are gathered 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, 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 catches per tow for fish taxa are available below. The latest published data is preliminary and will be updated in January of the following year. This data is also available via the 'Biodiversity' application on the St. Lawrence Global Observatory (SLGO). For more information please contact the data management team (gddaiss-dmsaisb@dfo-mpo.gc.ca).

Fisheries and Oceans Canada (DFO) conducts an annual multidisciplinary scientific survey with a bottom trawl in the Estuary and the northern Gulf of St. Lawrence since 1978. Over the years this survey has been conducted on four vessels: the MV Gadus Atlantica (1978-1994), the MV Lady Hammond (1984-1990), the CCGS Alfred Needler (1990-2005) and the CCGS Teleost (2004-2022). 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. 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. Inventory species biodiversity 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 aimed towing speed is 3 knots. Data For each fishing tow, the catch is sorted and weighed by taxa; individual are then count and biological data are then collected on a subsample. For fish, crab and squid, size and weight are gathered 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, 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 catches per tow for fish taxa are available below. This data is also available via the 'Biodiversity' application on the St. Lawrence Global Observatory (SLGO). For more information please contact the data management team (gddaiss-dmsaisb@dfo-mpo.gc.ca).

Fisheries and Oceans Canada (DFO) conducts an annual multidisciplinary scientific survey with a bottom trawl in the Estuary and the northern Gulf of St. Lawrence since 1978. Over the years, this survey has been conducted on four vessels: the MV Gadus Atlantica (1978-1994), the MV Lady Hammond (1984-1990), the CCGS Alfred Needler (1990-2005) and the CCGS Teleost (2004-2021). 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. The specificities of the missions onboard the MV Lady Hammond are described below. Objectives: 1. Assess groundfish populations abundance and condition 2. Assess environmental conditions 3. Inventory species biodiversity 4. Monitor the pelagic ecosystem 5. Collect samples for various research projects Survey description The survey covers 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). A stratified random sampling strategy is used for this survey and the fishing gear used on the MV Lady Hammond is a bottom trawl Western IIA. Standard trawling tows last 30 minutes, starting from the time the trawl touches the sea floor. Towing speed is 3.5 knots. Data For each fishing tow, the catch is sorted and weighed by taxa; individuals are counted and biological data are then collected. For fish, crab and squid, size and weight are gathered 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 otoliths are collected for redfish and Atlantic cod. Invertebrates are weighted and counted (no individual measurements). The catches per tow for fish taxa are available below. For more information please contact the data management team (gddaiss-dmsaisb@dfo-mpo.gc.ca).

Fisheries and Oceans Canada (DFO) conducts an annual multidisciplinary scientific survey with a bottom trawl in the Estuary and the northern Gulf of St. Lawrence since 1978. Over the years, this survey has been conducted on four vessels: the MV Gadus Atlantica (1978-1994), the MV Lady Hammond (1984-1990), the CCGS Alfred Needler (1990-2005) and the CCGS Teleost (2004-2021). 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. The specificities of the missions onboard the MV Lady Hammond are described below. Objectives: 1. Assess groundfish populations abundance and condition 2. Assess environmental conditions 3. Inventory species biodiversity 4. Monitor the pelagic ecosystem 5. Collect samples for various research projects Survey description This winter survey covers the northern Gulf of St. Lawrence, that is the divisions 4R, 4S and 3Pn of the Northwest Atlantic Fisheries Organization (NAFO). A stratified random sampling strategy is used for this survey and the fishing gear used on the MV Gadus Atlantica is an Engel 145 Otter trawl. Standard trawling tows last 30 minutes, starting from the time the trawl touches the sea floor. Towing speed is 3.5 knots. Data For each fishing tow, the catch is sorted and weighed by taxa; individuals are counted and biological data are then collected on a subsample. For fish, crab and squid, size and weight are gathered 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 otoliths are collected for Greenland halibut and Atlantic cod. Invertebrates are weighted and counted (no individual measurements). The catches per tow for fish taxa are available below. For more information please contact the data management team (gddaiss-dmsaisb@dfo-mpo.gc.ca).

Fisheries and Oceans Canada (DFO) conducts an annual multidisciplinary scientific survey with a bottom trawl in the Estuary and the northern Gulf of St. Lawrence since 1978. Over the years this survey has been conducted on four vessels: the MV Gadus Atlantica (1978-1994), the MV Lady Hammond (1984-1990), the CCGS Alfred Needler (1990-2005) and the CCGS Teleost (2004-2021). 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. The specificities of the missions onboard the CCGS Alfred Needler are described below. Objectives: 1. Assess groundfish and northern shrimp population abundance and condition 2. Assess environmental conditions 3. Inventory species biodiversity 4. Monitor the pelagic ecosystem 5. Inventory marine mammals populations 6. Inventory seabirds populations 7. Collect samples for various research projects Survey description The survey covers the divisions 4R, 4S, 3Pn and the northern part of division 4T of the Northwest Atlantic Fisheries Organization (NAFO). This survey follows a stratified random sampling design and the fishing gear used on the CCGS Alfred Needler is a URI shrimp trawl (81'/114'). Standard trawling tows last 25 minutes, starting from the time the trawl touched the sea floor. 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 then collected on a subsample. For fish, crab and squid, size and weight are gathered 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 collected for several species such as witch flounder, Atlantic cod, Greenland halibut and Atlantic halibut. 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 catches per tow for fish taxa are available below. This data is also available via the 'Biodiversity' application on the St. Lawrence Global Observatory (SLGO). For more information please contact the data management team (gddaiss-dmsaisb@dfo-mpo.gc.ca).

This inventory, conducted from September 26th to October 3th, 2019, aimed to describe the community structure of macroalgae and benthic macroinvertebrates of five small estuaries of the Upper North Shore of Quebec, namely Barthélemy Bay and the Colombier, Mistassini, Franquelin and Saint-Nicolas rivers. This inventory is part of a doctoral study of Valentine Loiseau on the global changes in the St. Lawrence system, mainly the study of marine benthic communities in response to changes of salinity, to ensure proper management of the environment in the face of future changes. The main objective is to describe the structure and the levels of specific diversities of mediolittoral communities of benthic macroinvertebrates and macroalgae along a salinity gradient.  These five small estuaries were selected because of their similar size, hard substrates and easy access. Three levels of hypoosmotic stress (low, medium, high) and one control level (seawater) were used for each of the selected estuaries, with eight quadrats per stress level. Quadrat positions were randomly selected but had to meet two criteria: (1) regular height in the foreshore to control the influence of other stresses (temperature, exposure); and (2) presence of at least one macroalga to maintain homogeneity. A percentage cover by macroalgal and macroinvertebrate species was estimated, and then all organisms were weighed by species and size group. The salinity of the nearest water point was measured at mid-tide with a portable refractometer and a Castaway-type CTD (Conductivity-Temperature-Density) probe. The inventory was done using a stratified random sampling design and the sampling unit was a quadrat measuring 25 x 25 cm. The three files provided (DarwinCore format) are complementary and are linked by the "eventID" key. The "event_information" file includes the generic information of the quadrat, including date and location. The "additional_information_event_and_occurrence" file includes the sampling protocol and effort, as well as the size, salinity and substrate type of the quadrat. The "taxon_occurrence" file includes the taxonomic inventory of macroalgal and benthic macroinvertebrate species observed in the quadrat, identified to the lowest possible species or taxonomic level and biomass by identified species. For quality control, organisms were identified on the field using the following guide: Chabot, Robert et Anne Rossignol. 2003. Algues et faune du littoral du Saint-Laurent maritime : Guide d'identification. Institut des Sciences de la mer de Rimouski, Rimouski ; Pêches et Océans Canada (Institut Maurice-Lamontagne), Mont-Joli. 113 pages. The taxonomy was checked against the World Register of Marine Species (WoRMS) to match recognized standards and using the R obistools and worrms libraries. The WoRMS match was placed in the "scientificNameID" field of the occurrence file. All sample locations were spatially validated. This project was funded by DFO Coastal Environmental Baseline Program under Canada’s Oceans Protection Plan. This initiative aims to acquire environmental baseline data contributing to the characterization of important coastal areas and to support evidence-based assessments and management decisions for preserving marine ecosystems.