Across the Canadian North, Arctic Char, Salvelinus alpinus, are culturally important and critical for maintaining subsistence lifestyles and ensuring food security for Inuit. Arctic Char also support economic development initiatives in many Arctic communities through the establishment of coastal and inland commercial char fisheries. The Halokvik River, located near the community of Cambridge Bay, Nunavut, has supported a commercial fishery for anadromous Arctic Char since the late 1960s. The sustainable management of this fishery, however, remains challenging given the lack of biological data on Arctic Char from this system and the limited information on abundance and biomass needed for resolving sustainable rates of exploitation. In 2013 and 2014, we enumerated the upstream run of Arctic Char in this system using a weir normally used for commercial harvesting. Additionally, we measured fish length and used T-bar anchor tags to mark a subset of the run. Subsequently, we estimated population size using capture-mark-recapture (CMR) methods. The estimated number of Arctic Char differed substantially between years. In 2013, 1967 Arctic Char were enumerated whereas in 2014, 14,502 Arctic Char were enumerated. We attribute this marked difference primarily to differences in weir design between years. There was also no significant relationship between daily mean water temperature and number of Arctic Char counted per day in either year of the enumeration. The CMR population estimates of Arctic Char (those ≥450mm in length) for 2013 and 2014 were 35,546 (95% C.I 30,513-49,254) and 48,377 (95% C.I. 37,398-74,601) respectively. The 95% CI overlapped between years, suggesting that inter-annual differences may not be as extreme as what is suggested by the enumeration. The population estimates reported here are also the first estimates of population size for an Arctic Char stock in the Cambridge Bay region using CMR methodology. Overall, the results of this study will be valuable for understanding how population size may fluctuate over time in the region and for potentially providing advice on the sustainable rates of harvest for Halokvik River Arctic Char. Additionally, the results generated here may prove valuable for validating current stock assessment models that are being explored for estimating biomass and abundance for commercial stocks of Arctic Char in the region.

The National Pollutant Release Inventory (NPRI) is Canada's public inventory of pollutant releases (to air, water and land), disposals and transfers for recycling. The files below contain a map of Canada showing the locations of all facilities that reported direct releases of Criteria Air Contaminants to the NPRI. The data are for the most recent reporting year, by reported total quantities of these releases. The map is available in both ESRI REST (to use with ARC GIS) and WMS (open source) formats. For more information about the individual reporting facilities, a dataset is available in a CSV format. Please consult the following resources to enhance your analysis: - Guide on using and Interpreting NPRI Data: https://www.canada.ca/en/environment-climate-change/services/national-pollutant-release-inventory/using-interpreting-data.html - Access additional data from the NPRI, including datasets and mapping products: https://www.canada.ca/en/environment-climate-change/services/national-pollutant-release-inventory/tools-resources-data/exploredata.html

The National Pollutant Release Inventory (NPRI) is Canada's public inventory of pollutant releases (to air, water and land), disposals and transfers for recycling. The files below contain a map of Canada showing the locations of all facilities that reported direct releases to surface waters to the NPRI. The data are for the most recent reporting year, by reported total quantities of these releases. The map is available in both ESRI REST (to use with ARC GIS) and WMS (open source) formats. For more information about the individual reporting facilities, a dataset is available in a CSV format. Please consult the following resources to enhance your analysis: - Guide on using and Interpreting NPRI Data: https://www.canada.ca/en/environment-climate-change/services/national-pollutant-release-inventory/using-interpreting-data.html - Access additional data from the NPRI, including datasets and mapping products: https://www.canada.ca/en/environment-climate-change/services/national-pollutant-release-inventory/tools-resources-data/exploredata.html

This record contains two datasets: 1. Raw unfiltered geographic coordinates and accuracy estimates of ringed seals tagged in the Western Canadian Arctic and 2. The location estimate from state-space models using a 12-hr time step. In total, 17 ringed seals were captured, measured, weighed, and tagged with satellite-linked transmitters (SDR-10, SDR-16, SPLASH) in June and July of 1999, 2000, and 2010. The tags, manufactured by Wildlife Computers Ltd. (Redmond, Washington, USA), sent data to polar orbiting satellites. Data were then retrieved via the Argos system (Harris et al., 1990). Tags collected and relayed information on movement (geographic positions) and diving data of the instrumented animals.

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.

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.

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.

This record contains data on bowhead whale locations 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

Fisheries and Oceans Canada (DFO) has conducted an annual summer multidisciplinary scientific bottom trawl survey 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 (2004-2021) and the CCGS Cabot (2022- on going). 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. Conduct a biodiversity inventory of benthic and demersal megafauna 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 collected on a sub-sample. 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 otoliths are collected for redfish and Atlantic cod. Invertebrates are weighted and counted (no individual measurements). The biological data are divided into 4 files: a “Stations” file containing set information, a “Catches” file containing catches per set for all 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 (for fish and certain invertebrate species), use the columns source_info, no_survey, nbpc, station_number, strap_code, and category. Data collection methods and sampling protocols have varied over the years. These changes may affect the comparability of the data across sampling periods. For more information about the protocols used, please contact the data management team (gddaiss-dmsaisb@dfo-mpo.gc.ca). It's 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. For more information please contact the data management team (gddaiss-dmsaisb@dfo-mpo.gc.ca).

This dataset provides projected sea surface temperature and salinity as well as projected ocean bottom temperature and salinity in the Northwest Atlantic under an intermediate emission scenario Representative Concentration Pathway (RCP) 4.5. The results are generated by a North Atlantic Ocean-ice Downscaling System (NAODS) that downscales the global Hedley Centre Global Environmental Model Version 2 with an Earth System component (HadGEM2-ES) output. NAODS couples a 1/12 ^o model for the northwest Atlantic with a 1/4 ^o model for the North Atlantic (Han et al., 2025). Bi-decadal means are included for 1986-2005, 2006-2025, 2026-2045, 2046-2065, 2066-2085, and 2080-2099, respectively.