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 redfish (Sebastes sp.) includes the metadata, sample weight, fish length, the sex and the number of specimens measured. This dataset covers the periods of 1980-1996, 1999-2013, 2015-2016 and 2019. 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.

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.

This data is from the Newfoundland and Labrador Region Multispecies Trawl survey, specific to Snow Crab from 2018-25, with only successful tows included in the database. Details of annual survey coverage and an overview of the survey program can be found in Rideout et al. (2025) and references therein. This trawl survey follows a depth-stratified random design, designated by type = 1 (Survey). From 2021-23, a comparative fishing program (i.e., direct side-by-side paired comparison between old and new vessels) was undertaken to determine differences in catchability due to vessel changes and associated modifications to the trawl gear with the retirement of the CCGS Alfred Needler and CCGS Teleost (called ‘old vessels’) and the introduction of the CCGS Capt. Jacques Cartier and CCGS John Cabot (called ‘new vessels’). During this period other set types are in the dataset (6 and 7) from paired tows and all station allocation may not have been stratified random. The DFO NL Region comparative fishing success varied by year, NAFO division, and vessel combinations and resulted in conversion factors to adjust the catches of Snow Crab in the old vessels time series into the same units as the new vessels. Methodologies and conversion factors are described in Wheeland et al. (2024), Trueman et al. (2025), Trueman et al. (2026), and Pantin et al. (in prep). Conversion factors have been applied to the numbers of Snow Crab caught, where conversion factors exist, and are in the converted_number column. An NA in the converted_number column indicates that conversion factors do not exist for this vessel/area combination and therefore direct comparisons cannot be made between old vessels and new vessels. Weights are those recorded at sea and do not have conversion factors applied. Analyses by the DFO NL Snow Crab group apply a length-weight relationship to the converted numbers to determine converted weights, which is not in this dataset. All reasonable attempts are made to standardize fishing time during trawl surveys, however there is always some variation in the actual time on bottom. The species weights and numbers in this dataset are not standardized for tow distance/duration. Spatial coverage of this survey has varied over time, therefore, not all divisions, or depths within divisions, are sampled every year or season. Biological measurements are described in Pantin et al. (2025). Tows that caught zero Snow Crab are denoted in the dataset by a ‘number’ of 0. References: McCallum, B. R., and S. J. Walsh. 1996. Groundfish survey trawls used at the Northwest Atlantic Fisheries Centre, 1971-present. NAFO Sci. Coun. Studies, 29: 93-104. Pantin, J., D. Mullowney, K. Baker, K. Lefort, W. Coffey, F. Cyr, H. Munro, and Koen-Alonso, M. 2025. An Assessment of Newfoundland and Labrador Snow Crab (Chionoecetes opilio) in 2023. DFO. Can. Sci. Advis. Sec. Res. Doc. 2025/080. iv + 152 p. Pantin, J., Charmley, K., Mullowney, D., Baker, K., Lefort, K., Coyne, J., Munro, H., and Koen-Alonso, M. In prep. An Assessment of Newfoundland and Labrador Snow Crab (Chionoecetes opilio) in 2024. DFO Can. Sci. Advis. Sec. Res. Doc. year/nnn. Rideout, R.M., Wheeland, L., Perreault, A., Regular, P., Skanes, K., Simms, L., and Makrides, J. 2025. Canadian (Newfoundland and Labrador Region) Multi-Species Research vessel Bottom Trawl Survey Report for Surveys Conducted in 2024. NAFO SCR Doc. 25/028: 1-68. Trueman, S., Wheeland, L., Benoît, H., Munro, H., Nguyen, T., Novaczek, E., Skanes, K., and Yin, Y. 2025. Results of Comparative Fishing Between the CCGS Teleost and CCGS Alfred Needler with the CCGS John Cabot and CCGS Capt. Jacques Cartier in the Newfoundland and Labrador Region in 2021 and 2022. DFO Can. Sci. Advis. Sec. Res. Doc. 2025/021. v + 237 p. Trueman, S., Wheeland, L., Pantin, J., Baker, K., and Mullowney, D. 2026. On the relative catchability of Snow Crab in the Newfoundland and Labrador Multispecies trawl surveys. DFO Can. Sci. Advis. Sec. Res. Doc. 2026/008. iv + 41 p. Wheeland, L., Skanes, K. and Trueman, S. 2024. Summary of Comparative Fishing Data Collected in Newfoundland & Labrador from 2021-2022. Can. Tech. Rep. Fish. Aquat. Sci. 3579: iv + 132 p.

This record contains results from chemical analysis including suspended nitrogen (mg/g), suspended carbon (mg/g), and phosphorus (mg/g) based on dry weight sediment samples collected in the Beaufort Sea.

To better understand patterns of temporal and spatial variation of fish assemblages in offshore waters of Lake Winnipeg (Manitoba, Canada), pelagic trawl tows were conducted at lakewide monitoring stations since 2002. Trawl samples collected during spring, summer, and fall from the south basin, channel, and north basin were used to study effects of season and geographic region within the lake on species biomass estimates.

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

A research survey on snow crab (Chionoecetes opilio) was conducted from July 1 to July 17, 2018 on the Lower North Shore of the Gulf of St. Lawrence between Havre-Saint-Pierre and Blanc-Sablon. The main objective of this survey was to assess the abundance of snow crab and benthic species associated with snow crab habitat. Only data for benthic species associated with snow crab habitat are presented in this dataset. Data were collected according to a fixed station sampling design consisting of 61 stations, between 46 and 230 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 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 average tow distance was approximately 25 m. 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. To obtain the abundance and biomass assessment, contact Cedric Juillet (cedric.juillet@dfo-mpo.gc.ca). For quality controls, all taxonomic names were checked against the World Register of Marine Species (WoRMS) to match recognized standards. The WoRMS match was placed in the "ScientificIDname" field of the occurrence file. Special cases were noted in the "commentsIdentification" field and selected specimens were confirmed with field photos. Data quality checks were performed using the R obistools and Worms libraries. All sampling locations were spatially validated.

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 Atlantic surfclam (Spisula solidissima) includes the metadata, sample weight and the shell width of the specimens measured. This dataset covers the period of 2003 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.

PURPOSE: To record hourly water temperatures throughout the Margaree watershed. DESCRIPTION: The Department of Fisheries and Oceans (DFO) has been deploying water temperature monitoring equipment since spring 1993 in the Margaree River watershed. Coverage has changed throughout the time series and there is little documentation regarding equipment used. In recent years data have been collected using VEMCOs. USE LIMITATION: To ensure scientific integrity and appropriate use of the data, we would encourage you to contact the data custodian.

This record contains data on beluga whale locations in the Mackenzie estuary reported in Harwood, L.A. and P. Norton (1996). Aerial survey data from the southeast Beaufort Sea, Mackenzie River estuary and west. Amundsen Gulf, July 1992. Canadian Data Report of Fisheries and Aquatic Sciences No. 964