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.

The Quebec region of the Department of Fisheries and Oceans (DFO) is responsible for the assessment of several fish and invertebrate stocks exploited in the Estuary and the northern Gulf of St. Lawrence. The commercial catches sampling program is one of the sources of information used to complete these assessments. The data collected by this program, at wharf or at sea, offers among other things the advantage of a relatively large spatio-temporal coverage and provides some of the necessary knowledge to assess the demography and the structure of the exploited populations. This program is implemented by specialized DFO staff whose main mandate is to collect biological data on groundfish, pelagic fish and marine invertebrate species that are commercially exploited in the various marine communities.The following species have been sampled by this program from 1976 to present:1. American lobster (Homarus americanus)2. American plaice (Hippoglossoides platessoides)3. Atlantic cod (Gadus morhua)4. Atlantic halibut (Hippoglossus hippoglossus)5. Atlantic herring (Clupea harengus)6. Atlantic lyre crab (Hyas araneus)7. Atlantic mackerel (Scomber scombrus)8. Atlantic surfclam (Spisula solidissima)9. Arctic Lyre Crab (Hyas coarctatus)10. Capelin (Mallotus villosus)11. Common softshell clam (Mya arenaria)12. Giant scallop (Placopecten magellanicus)13. Greenland halibut (Reinhardtius hippoglossoides)14. Green urchin (Strongylocentrotus droebachiensis)15. Iceland scallop (Chlamys islandica)16. Redfish (Sebastes sp.)17. Rock crab (Cancer irroratus)18. Sea cucumber (Cucumaria frondosa)19. Snow crab (Chionoecetes opilio)20. Stimpson surfclam (Mactromeris polynyma)21. Waved whelk (Buccinum undatum)22. White hake (Urophycis tenuis)23. Winter flounder (Pseudopleuronectes americanus)24. Yellowtail flounder (Limanda ferruginea)For more information concerning these species, see the «Related Products» section below.

SummaryThe Quebec region of the Department of Fisheries and Oceans (DFO) is responsible for the assessment of several fish and invertebrate stocks exploited in the Estuary and the northern Gulf of St. Lawrence. The commercial catches sampling program is one of the sources of information used to complete these assessments. The data collected by this program, at wharf or at sea, offers among other things the advantage of a relatively large spatio-temporal coverage and provides some of the necessary knowledge to assess the demography and the structure of the exploited populations. This program is implemented by specialized DFO staff whose main mandate is to collect biological data on groundfish, pelagic fish and marine invertebrate species that are commercially exploited in the various marine communities.DataThis dataset on the Atlantic halibut (Hippoglossus hippoglossus) includes the metadata, sample weight, fish length, the sex and the number of specimens measured. This dataset covers the period of 1995 to present. In order to protect the confidentiality of the sources, some informations (such as those concerning the vessel) have been excluded and others (such as the date of capture) have been simplified. Entries where there was only one vessel in a fishing area for a given year were also excluded. Further information including the fishing areas coordinates can be found by clicking on the «Atlantic and Arctic commercial fisheries» and «Fishing areas» links below.

2014 to 2023 demersal fish abundance in the Estuary and the Gulf of St. Lawrence. The abundance is expressed as a number of individuals per normalized trawl set. Each species is individually represented in the northern Gulf and in the southern Gulf. Input data are from the annual August (North) and September (South) multidisciplinary surveys.The demersal species represented are: Alewife, Alligatorfish, American Plaice, Arctic Alligatorfish, Arctic Hookear Sculpin, Arctic Shanny, Arctic Staghorn Sculpin, Atlantic Cod, Atlantic Eelpout, Atlantic Halibut, Atlantic Hookear Sculpin, Atlantic Poacher, Atlantic Spiny Lumpsucker, Atlantic Wolffish, Black Dogfish, Blacksnout Seasnail, Brill/Windowpane, Common Grenadier, Common Wolf Eel, Cunner, Daubed Shanny, Esmark's Eelpout, Fish Doctor, Fourbeard Rockling, Fourline Snakeblenny, Greenland Cod, Greenland Halibut, Haddock, Longfin Hake, Longhorn Sculpin, Lowfin Snailfish, Monkfish, Goosefish, Moustache Sculpin, Newfoundland Eelpout, Northern Hagfish, Ocean Pout, Rockfishes, Sea Sculpin, Sea Tadpole, Shorthorn Sculpin, Smooth Skate, Snakeblenny, Spatulate Sculpin, Spiny Dogfish, Spinytail Skate, Spotted Wolffish, Stout Eelblenny, Thorny Skate, Twohorn Sculpin, Vahl's Eelpout, Variegated Snailfish, White Hake, Winter Flounder, Winter Skate, Witch Flounder, Wolf Eelpout, Wrymouth and Yellowtail Flounder.PurposeSince 1990, the Department of Fisheries and Oceans has been conducting an annual multidisciplinary survey in the Estuary and northern Gulf of St. Lawrence using a standardized protocol. In the southern Gulf of St. Lawrence, these bottom trawl surveys has been carrying out each September since 1971. These missions are an important source of information about the status of the marine ressources.The objectives of the surveys are multiple: to estimate the abundance and biomass of groundfish and invertebrates, to identify the spatial distribution and biological characteristics of these species, to monitor the biodiversity of the Estuary and Gulf and finally, to describe the environmental conditions observed in the area at the moment of the sampling.The southern Gulf surveys are realized using the following standardized protocol:Hurlbut,T. and D.Clay (eds) 1990. Protocols for Research Vessel Cruises within the Gulf Region (Demersal Fish) (1970-1987). Can. MS Rep. Fish. Aquat. Sci. No. 2082: 143p.The sampling protocols used for the Estuary and northern Gulf surveys are described in details in the following publications:Bourdages, H., Archambault, D., Bernier, B., Fréchet, A., Gauthier, J., Grégoire, F., Lambert, J., et Savard, L. 2010. Résultats préliminaires du relevé multidisciplinaire de poissons de fond et de crevette d’août 2009 dans le nord du golfe du Saint-Laurent. Rapp. stat. can. sci. halieut. aquat. 1226 : xii+ 72 p. Bourdages, H., Archambault, D., Morin, B., Fréchet, A., Savard, L., Grégoire, F., et Bérubé, M. 2003. Résultats préliminaires du relevé multidisciplinaire de poissons de fond et de crevette d’août 2003 dans le nord du golfe du Saint-Laurent. Secr. can. consult. sci. du MPO. Doc. rech. 2003/078. vi + 68 p.Annual reports are available at the Canadian Science Advisory Secretariat (CSAS), (http://www.dfo-mpo.gc.ca/csas-sccs/index-eng.htm).Bourdages, H., Brassard, C., Desgagnés, M., Galbraith, P., Gauthier, J., Légaré, B., Nozères, C. and Parent, E. 2017. Preliminary results from the groundfish and shrimp multidisciplinary survey in August 2016 in the Estuary and northern Gulf of St. Lawrence. DFO Can. Sci. Advis. Sec. Res. Doc. 2017/002. v + 87 p.

In place since fall 1994, the sentinel fisheries program is the result of a collaboration between Fisheries and Oceans Canada (DFO) and Quebec and Newfoundland commercial fishermen's associations. Under this program, contracts are awarded by tender to fishermen’s associations to carry out fishing activities according to scientific protocols developed by DFO. The main objective of this survey is to collect data that will be used to calculate abundance indices for various fish stocks, including cod, Greenland halibut, Atlantic halibut and rockfish.Description of mobile surveyThe mobile gear sentinel fisheries of the northern Gulf of St. Lawrence are conducted in the sub-division 3Pn and the divisions 4R, 4S and the northern part of the division 4T of the Northwest Atlantic Fisheries Organization (NAFO). This program follows a stratified random survey plan according to depth strata, NAFO divisions and the type of substrate at the bottom. A standard tow is 30 minutes long and made at a speed of 2.5 knots. The fishing gear is a 300 Star Balloon trawl mounted on a Rock Hopper footgear. The trawl mesh size is 145 mm with a liner of 40 mm in the codend. Unless conditions at sea compromise safety during fishing activity, a retaining cable must be used to standardize the horizontal opening between vessels and the various depths fished. Data are collected by observers at sea or by technicians.The data contained in this program are divided into 4 different projects.-The summer series, carried out during the month of July-The fall series, which covers the period from 1995 to 2002-The winter series, to study the mixing between the different stocks-The CRP (Cod reproductive potential) series, which targets the reproductive potential.DataFor each trait, the total catch is sorted and weighed for each species. The number of individuals caught for each unmeasured fish species is noted. Biological data such as length, weight (sampled, per individual, gonad, liver and stomach), age, sex and maturity migth then be collected on a subsample of many species such as Atlantic halibut, Greenland halibut, lumpfish and Atlantic cod, using a variety of protocols. The biological data are divided into 4 files: a “Metadata” file containing set information, a “Catches” file containing catches per set for fish taxa, a “Carbio” file containing biological and morphometric measurements per individual, a “Freql” file containing the length frequency of fish.The data collected as part of this program is available below. It is important to note, however, that 1) only traits deemed successful have been retained; 2) historical data may contain inaccuracies; 3) the most recent survey is not available for validation purposes.

This dataset includes metrics of eelgrass traits related to bed structure, morphology, and physiology from field sites along the Atlantic coast of Nova Scotia, Canada. Field sites were located across a gradient of temperature and light conditions. Sampling was conducted in July to August, in 2017, 2021, and 2022. Seagrass density and plants were sampled at 10 haphazardly distributed sampling stations within each seagrass bed at approximately the same depth. Stations were ~10m apart and at least 2m from any seagrass-bare interface. Quadrats were used to determine vegetative and reproductive shoot density. Three plants from each sampling station were collected and processed in the laboratory for length and width leaf 3, number leaves per shoot, rhizome width, rhizome water soluble carbohydrates, and total leaf chlorophyll. Also included in this data temperature and light metric that summarize temperature and light conditions during the summer period.Cite this data as: Wong, M.C., Dowd, M. Data of eelgrass (Zostera marina) traits from the Atlantic Coast of Nova Scotia. Published: February 2025. Coastal Ecosystems Science Division, Maritimes Region, Fisheries and Oceans Canada, Dartmouth NS.For additional information please see:Wong, M.C., Dowd, M. Eelgrass (Zostera marina) Trait Variation Across Varying Temperature-Light Regimes. Estuaries and Coasts 48, 13 (2025). https://doi.org/10.1007/s12237-024-01439-3

This dataset includes metrics of eelgrass size, cover, and biomass from field sites along the Atlantic coast of Nova Scotia, Canada. Field sites were located across a gradient of environmental conditions, and field sampling was conducted in July to August 2022. Eelgrass percent cover, shoot density, and plants were sampled at 10 haphazardly distributed sampling stations within each eelgrass bed at approximately the same depth. Stations were ~10m apart and at least 2m from any eelgrass-bare interface. At each sampling station eelgrass leaves in a 0.5 x 0.5m quadrat were photographed for later computer image analysis to determine percent cover. The number of shoots were then counted in a 0.25 x 0.25m quadrat, and 3 vegetative shoots were collected. Shoots were measured for leaf length, width, and weight in the laboratory. These data were used to determine allometric and cover-biomass relationships for use in non-destructive estimation of bed biomass. Cite this data as: Wong, M.C., & Thomson, J. A. Data of eelgrass (Zostera marina) plant size (length, width), cover, and biomass from the Atlantic Coast of Nova Scotia. Published: February 2025. Coastal Ecosystems Science Division, Maritimes Region, Fisheries and Oceans Canada, Dartmouth NS.For additional information please see:Thomson, J. A., Vercaemer, B., & Wong, M. C. (2025). Non-destructive biomass estimation for eelgrass (Zostera marina): Allometric and percent cover-biomass relationships vary with environmental conditions. Aquatic Botany, 198, 103853. https://doi.org/10.1016/j.aquabot.2024.103853

Nekton assemblages in Zostera marina beds and adjacent bare soft-sediments were sampled on the south and eastern shore of Nova Scotia. Sampling gear used were visual snorkel transects and a benthic beam trawl. Fish were identified and size either measured (trawl) or estimated in situ (snorkel transects). Surveys were conducted in mid-July to August in summer of 2013 and 2014 across multiple sampling sites. Multiple replicate transects were conducted at each site. Raw abundances from observations were transformed into young of year (YOY) equivalent abundance, and then into density of each species calibrated to account for the sampling equipment and day/night differences.Cite this data as: Wong, M. C. Data of: Fish and large decapods in eelgrass (Zostera marina) beds on the Atlantic coast of Nova Scotia, Canada. Published: April 2020. Coastal Ecosystems Science Division, Fisheries and Oceans Canada, Dartmouth, N.S. https://open.canada.ca/data/en/dataset/dbc56f11-4a97-45e7-99f4-71966b51630c

Mean fork length for returning adult Atlantic salmon (Salmo salar) that spent one or two years (1SW and 2SW, respectively) in the marine environment for 16 rivers throughout Eastern Canada spanning an 10° latitudinal gradient. These data were collected as part of monitoring programs for Atlantic salmon returns run by Fisheries and Oceans Canada (DFO). Data from at least eight populations, spanning all provinces in Atlantic Canada, over a 50-year period (1970-2021) will be included in this meta-analysis.These data, as well as mean fork length for returning adult Atlantic salmon from three rivers in Québec (1979-2021) collected as part of monitoring programs for Atlantic salmon returns run by the Ministère de l’Environnement, de la Lutte contre les changements climatiques, de la Faune et des Parcs, Government of Québec, are also available at: http://doi.org/10.17605/OSF.IO/78PWT.

Monitoring of Unit 2 redfish by Fisheries and Oceans Canada (DFO) ceased in 2002. Since then, the Atlantic Groundfish Council (AGC, formerly the Groundfish Enterprise Allocation Council [GEAC]) has funded surveys approximately every two years in the area, in collaboration with DFO. Over the years, various vessels and gear types have been used. In 2024, a comparative survey was conducted using the CCGS John Cabot and a fishing industry vessel (the Léry Charles) to develop conversion factors that allow data from the 2020, 2022, and 2024 Unit 2 redfish surveys to be standardized to CCGS John Cabot equivalents. The survey covered the waters off southwestern Newfoundland and eastern Cape Breton, corresponding to redfish management Unit 2, which includes NAFO subdivisions 3Pn, 3Ps, 4Vn, 4Vs, and 4W. Here, data collected aboard the CCGS John Cabot are presented. Objectives• Assess the abundance and condition of groundfish and invertebrates• Assess environmental conditions• Inventory the biodiversity of benthic and demersal megafauna• Monitor the pelagic ecosystem• Collect samples for various research projectsData The CCGS John Cabot employed a four-sided modified Campelen 1800 shrimp trawl, fitted with a Rockhopper ("bicycle") footgear. The trawl extension and codend were lined with 12.7 mm knotless nylon mesh. Standard trawl tows were 15 minutes in duration, timed from bottom contact, with a target towing speed of 3 knots.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, and Greenland halibut. Roughly 2-kg of shrimp are sorted and weighed by species. 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 is important to note that this is raw data. Only sets considered successful are retained. In each set, all species are kept, with a few exceptions. Data is available from 1997-2022 but please contact the data management team (gddaiss-dmsaisb@dfo-mpo.gc.ca) for access and further details. For any other information please also contact the data management team.