PURPOSE: To provide access to detailed stomach content data and associated metadata from Atlantic Bluefin Tuna sampled in the southern Gulf of St. Lawrence from 2018 to 2023. These data support fisheries science by contributing to analyses of predator–prey dynamics, diet composition, and ecosystem understanding, as well as informing stock assessment and fisheries management activities within Fisheries and Oceans Canada. DESCRIPTION: This dataset contains metadata and stomach content information collected from Atlantic Bluefin Tuna (ABFT) caught from mid-August to late September in the commercial fishery in the southern Gulf of St. Lawrence between 2018 and 2023. Stomach samples were primarily obtained from fish harvested near the eastern end of Prince Edward Island, with additional samples collected from the Miscou/Baie‑des‑Chaleurs area in 2018 and 2019. SAMPLING METHODS: Fish were measured to the nearest curved fork length (cm) and weighed to the nearest round weight (kg). Stomachs were obtained directly from harvesters or through a fish buyer and were stored at −20 ◦C before being processed in the laboratory. Stomachs identification numbers were cross-referenced with ABFT tag numbers recorded by fish provider in order to obtain logbook and port data (catch location, time, weight length, sex, gear, etc.) for each sample. Stomachs were thawed in the laboratory and the content was sorted and identified to the lowest possible taxonomic level. For each stomach, prey were weighed collectively as a taxonomic group and individually to the nearest 0.1 g. Dead bait used to capture ABFT, identified by cut marks, were recorded and weighed but excluded from the analysis. Live bait items cannot be identified from stomach content analyses. Only a few otoliths were found in 2018 and their degraded quality precluded performing ageing or species identification. Rare and small prey items such as algae and rocks were classified in the category “other”. Fish remains that could not be identified were classified in the category “Unidentified teleostei remains”. For 2019 to 2023, when stomach content items could not be visually identified and when tissue was available, tissue samples were collected and stored at −20 °C for DNA barcoding analysis. DNA extraction, mitochondrial cytochrome oxidase subunit 1 amplification, Sanger sequencing and species assignation were performed at the Plateforme d’Analyses Génomiques and Plateforme Bio-informatique of the Institut de Biologie Intégrative et des Systèmes (PAG-IBIS, Université Laval, Quebec city, QC, Canada, http://www.ibis.ulaval.ca/en/services-2/genomic-analysis-platform/). DNA was extracted from 20 mg of muscle tissue using the Omega Bio-tek E-Z-96 Tissue DNA Kit (Omega Bio-tek, Norcross GA, USA) following manufacturer instructions. The mitochondrial cytochrome oxidase subunit 1 region was amplified and sequenced as described in Hashemzadeh Segherloo et al., 2021). Sanger forward and reverse reads were analyzed independently using the Basic Local Alignment Search Tool against non-redundant sequences to identify the top hit for each sequence. When samples could not be identified by a top hit sequence they were classified as “unidentifiable fish”. Prey items that were successfully identified using DNA barcoding were incorporated into the stomach content analysis database and used in all subsequent diet analyses (abundance, occurrence and weight). The weight of the items used in the database was the weight of the remains as they were, and not reconstructed weights calculated for a live animal of the species identified by the barcoding. USE LIMITATION: To ensure scientific integrity and appropriate use of the data, we would encourage you to contact the data custodian.

Summary 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. Data This dataset on the common softshell clam (Mya arenaria) includes the metadata, sample weight, the shell width and the number of specimens measured. This dataset covers the periods of 1994 and 2004-2010. 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.

A research survey on snow crab (Chionoecetes opilio) was conducted on the Lower North Shore of the Gulf of St. Lawrence between Havre-Saint-Pierre and Blanc-Sablon in 2018, 2022 and 2024. The main objective of this survey was to assess the abundance of snow crab and species associated with snow crab habitat. Only data for benthic and demersal species associated with snow crab habitat are presented in this dataset. Data were collected according to a fixed station sampling design. A total of of 62 stations were sampled in 2018, 54 in 2022, and 46 in 2024, between 45 and 250 meters depth. Specimens were collected using a beam trawl with a total width of 2.8 meters and a total height of 0.76 meters. The codend was lined with a 16-17 millimeter stretched mesh net in order to harvest the small individuals. The hauls were made at a target speed of 2 knots and a target duration of 10 minutes depending on seabed conditions. Start and end positions were recorded to calculate the distance traveled on each tow using the geosphere library in R. The area covered at each tow was the product of the trawl opening and the distance traveled. The two files provided (DarwinCore format) are complementary and are linked by the "eventID" key. The "Activity_Information" file includes generic activity information, including date and location. The "occurrence_taxon" file includes the taxonomy of the species observed, identified to the species or lowest possible taxonomic level. For quality controls, all taxonomic names were checked against the World Register of Marine Species (WoRMS) to match recognized standards. All sampling locations were spatially validated. Abundance and density data for crabs under different size classes are available in a joint publication https://open.canada.ca/data/en/dataset/814e48c9-2dc7-4526-bd37-a4a120d66d6e

The contaminants in fish database is a compilation of contaminant data analysed from fish tissue at the Fresh Water Institute from 1970 to 2005. Data include lab number, region, analysis, organs, species, lake, form (whole fish, headon dressed, headless dressed), weight, and length and contaminant concentrations. Total mercury was the predominant contaminant measured. Results were expressed as ppm or ppb based on the parameter analyzed. Concentrations are expressed based on wet weight.

PURPOSE: To track juvenile Atlantic salmon densities. DESCRIPTION: Indices of freshwater production are derived annually from electrofishing surveys in the rivers of Nova Scotia flowing into the Gulf of St. Lawrence. Fixed site sampling for juvenile salmon has been conducted most consistently since the mid-1980s for these rivers. Juvenile salmon abundances at sites, in terms of number of fish per habitat area sampled by age or size group (densities), are obtained using successive removal sampling or catch per unit effort sampling calibrated to densities. Sampling intensities vary among years and among rivers. PARAMETERS COLLECTED: distribution (ecological); species counts (ecological); point (spatial) USE LIMITATION: To ensure scientific integrity and appropriate use of the data, we would encourage you to contact the data custodian.

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 conduct fishing activities in accordance with scientific protocols developed by DFO. The primary objective of this survey is to collect data used to calculate abundance indices for various fish stocks, including cod, Greenland halibut, Atlantic halibut and rockfish. Description of mobile survey The mobile gear sentinel fisheries program began in 1999. It takes place in the northern Gulf of St. Lawrence and is 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 design based on depth strata, NAFO divisions and bottom substrate type. A standard tow is 30 minutes long and conducted at a speed of 2.5 knots. The fishing gear consists of a 300 Star Balloon trawl mounted on a Rock Hopper footgear. The trawl has a mesh size of 145 mm, with a 40 mm liner in the codend. Unless sea conditions compromise fishing safety, a retaining cable must be used to standardize the horizontal opening of nets 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 (1999 -ongoing) -The fall series, which covers the period from 1999 to 2002 -The winter series, to study the mixing between the different stocks, which covers the period of 2002-2006 -The CRP (Cod reproductive potential) series, which targets the reproductive potential of cod and typically takes place during the month of May (2002-ongoing) Data For each fishing tow, 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 can then be collected from a subsample of multiple species such as Atlantic halibut, Greenland halibut, lumpfish and Atlantic cod, according to various protocols. The biological data are divided into 4 files: a “Stations” file containing set information, a “Catches” file containing catches per set for fish taxa, a “Carbio” file containing biological and morphometric measurements per individual, and a “Freql” file containing the length frequency of fish. The columns source_info, no_survey, nbpc and station_number serve as a common key linking the four datasets. To further link the “Captures” and the “Carbio” files to the species level, use the columns source_info, no_survey, nbpc, station_number, strap_code, and category. 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. For more information please contact the data management team (gddaiss-dmsaisb@dfo-mpo.gc.ca).

Greenland halibut (Reinhardtius hippoglossoides) occupy deep waters off Newfoundland and Labrador and are a commercially important species. The Groundfish Section, Fisheries and Oceans Canada – Newfoundland and Labrador Region implemented an acoustic tagging program to better understand the movement and habitat use for this species. This program began in 2021, and was further developed as a results of two DFO Competitive Science Research Fund project between 2022-2026. Fish were caught via trawl or longline, VEMCO acoustic transmitters surgically implanted, and released at site of capture. Detections occurred from acoustic receivers deployed by the Groundfish section and/or from receiver arrays associated with the Oceans Tracking Network (e.g. Northern Cod Acoustic Telemetry Array [NCAT]). Raw detection data are downloaded from receivers and sent to the Ocean Tracking Network for formatting and archiving. Data provided here summarize reported detections from 2021-2024 as part of a master’s project at Memorial University of Newfoundland. Release locations, number and location of detections, defined movement class, and detection duration are summarized by individual. Location information includes the position of the receiver the fish was detected at, and the North Atlantic Fisheries Organization (NAFO) Divisions where fish were detected in.

This dataset contains observations of species occurrences from seafloor imagery collected by the autonomous underwater vehicle (AUV) during the 2012 Expedition to Cobb Seamount. The National Oceanographic and Atmospheric Administration-operated SeaBED-class AUV which collected photographic images from 4 transects ranging from 436 m to 1154 m in depth.

The purpose of the survey is to document and record habitat types and associated algae and marine invertebrate species in a variety of habitat types. Transect locations are randomly selected throughout the study area, which rotates between the north and south coasts of British Columbia on a biannual basis. Transects are laid perpendicular to the shoreline. A team of two divers swim the transect with data sheets to collect habitat, algae and marine invertebrate data as detailed below in the methods section. Data is keypunched in an MS Access database that can be queried for species observations and environmental information. This dataset includes three tables pulled from the original database containing observations by species, observations by quadrat, and additional header information for each observation. All three tables can be linked by the field HKey. Three lookup tables are included as well, one for algae, one for invertebrates, and one for substrates.

The objective of the Canadian Wildlife Service (Ontario Region) Acid Rain Biomonitoring Program (ARBP) was to evaluate the response of biological communities in acidified, damaged and acid sensitive lakes and wetlands in response to regulation driven changes in deposition of acidifying pollutants. Supported by a research phase from 1981-1987, the biomonitoring program began in 1988 and ended in 2010. The program primarily focused on the small lakes and wetlands important to breeding aquatic birds, with many of the study lakes being headwaters or otherwise located in the upper reaches of watersheds. Beginning in the late 1980s, monitoring and studies focused on the Algoma (Block 12), Sudbury (Block 37) and Muskoka (Block 1) regions of Ontario. The Experimental Lakes Area (ELA; Block 24) was added as a fourth study area and was sampled in 2002 and 2009. The ARBP involved three main monitoring components. The water sampling component targeted approximately 250 to 350 lakes per year, with the schedule for Algoma, Sudbury and Muskoka aiming for a rotation such that a subset of lakes were sampled in adjacent years. Lakes were sampled near fall overturn using a helicopter on floats and water column samples were obtained from the deepest part of each sample lake. The breeding waterfowl survey targeted approximately 775 lakes (Algoma 242, Sudbury 176, Muskoka 250, ELA 107) with two study areas usually targeted each year. Surveys were done by helicopter equipped with bubble windows, a navigator/observer in front and two observers in the rear seats. Surveys were timed to target pairing and breeding initiation (typically May), with brood surveys (July) occurring in years of available human and financial resources. The food chain monitoring component targeted approximately 10 to 20 lakes in each study area, with a single study area usually targeted each year. Sampling was conducted by canoe in June and was designed to sample macroinvertebrates, amphibian larva, and small fish. The CWS-ON ARBP was conducted within a multidisciplinary program led by Environment Canada (currently Environment and Climate Change Canada). Under this program, federal and provincial scientists and academic researchers joined to advance the understanding, status reporting, and forecasting of the acid rain problem with respect to pollutant emissions, deposition, and effects on aquatic and terrestrial systems. Data from the CWS-ON ARBMP were analysed and reported in national Acid Deposition Science Assessments (1990, 1997, and 2004), science journals, and reports. Below is a list of documents providing additional information about the Acid Rain Biomonitoring Program (Canadian Wildlife Service, Ontario Region): 1. McNicol, D.K.; Mallory, M.L.; Sechley, J. 1998. Acid Rain and Wildlife: An Annotated Bibliography of Canadian Wildlife Service (Ontario Region) LRTAP Program Publications (1980 – 1997). Technical Report Series No. 305, Canadian Wildlife Service, Ontario Region. Available in English only: https://publications.gc.ca/collections/collection_2018/eccc/cw69-5/CW69-5-305-eng.pdf 2. Environment Canada. 2004. Canadian Acid Deposition Science Assessment. Available in English only: https://publications.gc.ca/collections/Collection/En4-46-2004E.pdf 3. McNicol, D.K.; Kerekes, J.J.; Mallory, M.L.; Ross, R. K.; Scheuhammer, A.M. 1995. The Canadian Wildlife Service LRTAP Biomonitoring Program, Part 1. A Strategy to Monitor the Biological Recovery of Aquatic Ecosystems in Eastern Canada from the Effects of Acid Rain. Technical Report Series No. 245, Canadian Wildlife Service, Ontario Region. Available in English only: https://publications.gc.ca/collections/collection_2018/eccc/cw69-5/CW69-5-245-eng.pdf 4. McNicoI, D.K.; Mallory, M.L.; Bendell, B.E. 1996. The Canadian Wildlife Service LRTAP Biomonitoring Program, Part 2. Food Chain Monitoring in Ontario Lakes: Taxonomic Codes and Collections. Technical Report Series No. 246, Canadian Wildlife Service, Ontario Region. Available in English only: https://publications.gc.ca/collections/collection_2018/eccc/cw69-5/CW69-5-246-eng.pdf 5. McNicoI, D.K.; Mallory, M.L.; Kerekes, J.J. 1996. The Canadian Wildlife Service LRTAP Biomonitoring Program, Part 3. Site locations, Physical, Chemical and Biological Characteristics. Technical Report Series No. 248, Canadian Wildlife Service, Ontario Region. Available in English only: https://publications.gc.ca/collections/collection_2018/eccc/cw69-5/CW69-5-248-eng.pdf