Since 1992, scientific surveys have been conducted annually alternately, in the estuary and the North of the Gulf of Saint Lawrence. These surveys allow DFO to monitor the population and ecosystem of the snow crab and thus understand the state of the stock and the renewal of the species.Beam trawl hauls following a systematic sampling take place every 2 years in the estuary and in the Lower North Shore. In the estuary (zone 17), a sampling of 94 stations is carried out. In the Lower North Shore (zone 13 and 14), 60 regular stations are usually sampled and 35 exploratory stations are distributed between Baie Johan Bettz and Kegaska (zone 15 and 16) but also on the south shore of zone 13 near Newfoundland. At each station, a fishing haul of 5 to 10 minutes is carried out. The harvested crabs are measured (cephalothorax width), sexed and counted. The state of the shell, sexual maturity and egg development stages are also assessed. The number of crabs caught, classified according to different size categories, allows estimating densities and thus monitoring the state and renewal of the snow crab population in the different fishing areas. This dataset on the snow crab (Chionoecetes opilio) contains abundance and density data of crabs under different size classes as well as geographical and bathymetric variables by station. The dataset covers the period from 1992 to the present and is updated each year. A cleaning of aberrant data has been carried out.For certain time periods, associated species are identified and semi-quantitatively counted directly on the sorting table, and the results are presented in the following publications: - https://open.canada.ca/data/en/dataset/8fbd81a4-ce4a-40e3-81f6-e2a5c44955de- https://open.canada.ca/data/en/dataset/268bf29e-b9d6-4267-bc86-230f4edfb80b- https://open.canada.ca/data/en/dataset/97dac757-2ef6-4144-b7d9-a0d8d51f8319

Likelihood of presence of Snow Crab in the Bay of Fundy and Port Hawkesbury areas. The Coastal Oceanography and Ecosystem Research section (DFO Science) reviewed science sources and local knowledge sources to estimate where Snow Crab are seasonally present and delineate these areas. As of March 2017, this dataset delineates the presence of snow crab in the Bay of Fundy and Port Hawkesbury areas of Nova Scotia designated within the Area Response Planning (ARP), identified under the World Class Tanker Safety System (WCTSS) initiative, based on the Transport Canada's Response Organizations Standards.A version of this dataset was created for the National Environmental Emergency Center (NEEC) following their data model and is available for download in the Resources section.Cite this data as: Lazin, G., Hamer, A.,Corrigan, S., Bower, B., and Harvey, C. Data of: Likelihood of presence of Snow Crab in Area Response Planning pilot areas. Published: June 2018. Coastal Ecosystems Science Division, Fisheries and Oceans Canada, St. Andrews, N.B. https://open.canada.ca/data/en/dataset/edb15c7b-d901-46b0-a460-1aca22c013ea

An annual trawl survey is conducted in Southwestern Nova Scotia and the Bay of Fundy to assess the lobster stocks in the area. The survey is conducted with the Northeast Fisheries Science Center Ecosystem Survey Trawl (NEST), a small mesh trawl with a cod end liner, which ensures the capture of various sizes of lobster. The dimensions and location of the trawl are monitored and recorded throughout the tow using an electronic trawl mensuration system. In addition, water temperature and depth are also monitored. The target tow length is 1 kilometer which is tracked using an Olex marine charting system. Vessel crew, DFO science staff and a contracted at sea observer work together to perform required tasks and collect all relevant data. Catch from each tow is separated by species, weighed and counted. Length frequency data is collected on select groundfish and crab species and detailed morphometric data is collected on each lobster.PARAMETERS COLLECTED:Set information and profile - includes set date, time depth and locationCatch summary - weight and number caught of each speciesLength Freqeuncies - completed for up to 100 fish for selected speciesLobster Morphological Data - detailed data collected on each lobsterBottom TemperatureTrawl MetricsNOTES ON QUALITY CONTROL:Data is visually verified and double keypunched. On loading to Oracle, data is run through rigorous automated checks to verify data accuracy and integrity.SAMPLING METHODS:The target tow length is 1 kilometer which is tracked using an Olex marine charting system. Vessel crew, DFO science staff and a contracted at sea observer work together to perform required tasks and collect all relevant data. Catch from each tow is separated by species, weighed and counted. Length frequency data is collected on select groundfish and crab species, detailed morphometric data is collected on each lobster. Bottom temperature and trawl metrics are collected for each tow.CITATION LIST:Denton, Cheryl M.. 2020. Maritimes Region Inshore Lobster Trawl Survey Technical Description. Canadian technical reports of fisheries and aquatic sciences (DFO) 3376.

This project was completed by the Shellfish Section in the Newfoundland and Labrador Science Branch of Fisheries and Oceans Canada (DFO), in collaboration with industry partners. The Coastal Environmental Baseline program supported the Placentia Bay portion of project work for an ongoing industry-DFO collaborative post-season trap survey for Snow Crab that was initiated in 2003 and has occurred each year. This survey is conducted by Snow Crab harvesters accompanied by at-sea observers and takes place in NAFO Divisions 2J3KLNOP4R. Historically the survey focused on commercial fishing grounds but began transitioning to a partly random stratified design in 2017. Since 2018, approximately 50% of survey stations are randomly allocated while 50% remain fixed. At each station, six (for inshore stations) or ten (for offshore stations) commercial traps are set in a fleet. To gather data on non-commercial sized Snow Crab, including females, many fleets also include one small-mesh trap. The coverage of small-mesh traps has been expanding in recent years with the aim of one small-mesh trap for every station in the coming years. Biological sampling is undertaken on at least one commercial trap and the small-mesh trap at each station. The data from this survey is incorporated into the annual stock assessment for Snow Crab in the Newfoundland and Labrador region. This record contains trap locations for Placentia Bay, and information on the types of data collected. More detailed information can be found in Pantin et al. (2022).https://publications.gc.ca/collections/collection_2023/mpo-dfo/fs70-5/Fs70-5-2022-076-eng.pdf

This data report provides information on temperature and salinity in the Godbout region of the St. Lawrence Estuary. Sampling was carried out from 2019 to 2021 over an area of <5 km2. The databases provide information on temperature and salinity at an hourly rate for 2 years. The aim of this project is to analyze telemetry data from sea urchins (Strongylocentrotus droebachiensis), snow crabs (Chionoecetes opilio), rock crabs (Cancer irroratus), spider crabs (Hyas spp.) and whelks (Buccinum undatum). This report focuses on the presentation of benthic environmental data collected throughout the study with high spatial and temporal resolution. All reported variables were collected at the seafloor, as the aim of the project was to study the movement of epibenthic species. Temperature data were collected from three devices: telemetry receivers with integrated temperature sensors (InnovaseaTM), HoboTM and Star-OddiTM probes. Temperature data processing involved cleaning up extreme values (below 2°C and above 20°C) and homogenizing the data to fit the bathymetry matrix (1m x 1m cells) of the study site. Temperature data are provided in a NetCDF file with a matrix of the entire study site, where there is a stratum for each hour between August 2019 and October 2021 and in each file, a temperature value for each pixel of the raster. Salinity data were collected from Star-OddiTM probes only. Salinity values were averaged hourly for the entire study area. Salinity data is provided as a CSV file with one salinity value per hour for the entire study area.

A research survey on American lobster (Homarus americanus) and rock crab (Cancer irroratus) has been carried out annually on the Magdalen Islands since 1995 to assess the abundance and structure of populations in this area. The survey is carried out during the first two weeks of September and covers the southern part of the Magdalen Islands, from "Baie de Plaisance" to "Grande-Entrée", extending slightly eastwards between "Havre-aux-Maisons" and "Grande-Entrée". The survey lasts 8 to 15 days, depending of the weather conditions, and covers a maximum of 48 stations. Approximately half of the stations are surveyed in duplicate (two tows per station). The tows always cover 500 meters, with a slightly variable trawl opening (as explained above), averaging around 10 meters.The gear used is a Nephrops trawl, a benthic trawl originally developed for langoustine fishing in Brittany, but slightly modified to target lobster. The trawl is deployed from the CCGS Leim and the harvested organisms are hauled aboard and sorted. Cephalothorax length, sex and shell stage are recorded for all lobsters. This is supplemented by information on reproductive conditions for certain size classes, and dissections of 25 males and 25 females per mission. Rock crabs are also included in the survey and are counted with additional measurements of shell width, sex and shell condition that are recorded on predetermined stations. For other stations individuals data are collected depending on the time available between trawl hauls.The publication contains 4 files; the "Information_stations" file which contains the data of the stations, the "Data_homard_lobster_survey" file which contains the measurements of each lobster, the "Nombre_crabe_crab_number" file which contains the count of rock crabs, the "Mesure_crabe_crab_measurement" file contains the characteristics measured for each crab. Each of the files can be linked by the "date", "st", "tr" columns. The “bat” column notes the boat code, because the gear is not deployed in the same way on each boat.*This record consist of raw data and quality has not been verifiedAssociated species are identified and semi-quantitatively counted directly on the sorting table, and the results are presented in the following publication: https://open.canada.ca/data/en/dataset/99cb7034-f3d5-4da4-a5bc-e81315cfb8eb

PURPOSE:Provide presence/absence and abundance data for the non-indigenous and invasive European green crab (EGC) in selected southern Gulf of St. Lawrence (sGSL) estuaries along the Northumberland Strait coast of New-Brunswick and eastern Prince-Edward-Island.DESCRIPTION:Temporal monitoring during ice-free seasons of European green crab abundance is completed in response to previous regional population declines in the Maritime provinces. Note that where presence is not indicated on the map does not mean absence - this survey is limited to a few sites.Traps that did not fish correctly were not included in the dataset. Examples of defective traps include: an open trap, an open bait container, a trap filled with algae and falling into the open position, a trap that has not been fished for over 48 hours, an overturned trap, or a trap that has been significantly moved or otherwise tampered with.Population estimates are not derived from this data. PARAMETERS COLLECTED:1) EGC count, size measurement, sex, and catch weight2) Counts of bycatch species. Categories reported in this dataset are finfish (cunner, striped bass, mummichog, winter flounder, smooth flounder, sculpin, tomcod, American eel, banded killifish, flounder, unknown bony fish), Atlantic rock crab, American lobster, and other (lion's mane jellyfish, moon jellyfish, other crabs, moon snail). Other smaller species were often in the trap but were not included as bycatch in this dataset as they can easily escape the mesh size and would not consistently be trapped. 3) Environmental data: water depth at trap setting, sediment type, vegetation types noted, salinity, water temperature, dissolved oxygen (not included), specific conductance (not included), conductivity (not included), weather, cloud cover (not included), tide state and direction (upon fishing).NOTES ON QUALITY CONTROL:Data entry of morphological parameters randomly verified for accuracy.Weights are not reported for PEI sites due to inconsistencies with types of weighing scales and measurement protocols.PHYSICAL SAMPLE DETAILS:Whole European green crab specimensSAMPLING METHODS:Baited trapping with Fukui traps. Bait was in a bait can or bag. Types of bait included herring (predominant type used), as well as other species when herring were not available (gaspereau, canned fish [tuna, kippers, snack sardines], mackerel, tilapia, and perch).USE LIMITATION:To ensure scientific integrity and appropriate use of the data, we would encourage you to contact the data custodian.

Fisheries and Oceans Canada (DFO) conducts an annual summer multidisciplinary scientific survey with a bottom trawl 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-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 Alfred Needler are described below.Objectives:1. Assess groundfish and northern shrimp population abundance and condition2. Assess environmental conditions3. Conduct a biodiversity inventory of benthic and demersal megafauna4. Monitor the pelagic ecosystem5. Collect samples for various research projectsSurvey descriptionThe 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.DataFor 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 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 biological data are divided into 5 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 and a “Shrimps” file containing information on shrimp catches.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 data is from the Newfoundland and Labrador Region Inshore Trap survey, specific to Snow Crab from 2018-25, with only successful sets included in the database. Details of annual survey coverage and an overview of the survey program can be found in Pantin et al. (2025). This trap survey follows a depth-stratified random survey design, designated by type = 1 (Survey). Data were available from DFO inshore trap surveys in Fortune Bay, St. Mary’s Bay, Conception Bay, Trinity Bay, Bonavista Bay, Notre Dame Bay, White Bay, and infrequently along the Northeast Avalon Peninsula. All surveys follow a depth-stratified survey design with set locations randomly distributed within each stratum, and stratum-specific set allocations weighted by area. All surveys utilize large-mesh (5.25”) and small-mesh (42 mm) traps intermittently placed within each ‘fleet’ of gear, with traps spaced approximately 45 m (i.e., 25 fathoms) apart. Each fleet includes six baited traps, with two additional end traps not baited. Squid (Illex spp.) hung on skivers is attached to the inner entry cone of each trap as bait, with approximately 2–3 pounds of squid on each skiver. Although soak times are intended to be standardized to 24–48 hours, weather and other factors can affect the surveys and soak times are ultimately variable. Biological sampling is conducted at-sea from all traps at each station and is described in Pantin et al. (2025). Whole weights of Snow Crab are not always taken for every crab (e.g., in poor weather, missing limbs, carapace covered in biofouling) and those without measurements are denoted by an NA in the dataset. Analyses by the DFO NL Snow Crab group apply a length-weight relationship to determine weights, which is not in this dataset. Traps that caught zero Snow Crab are denoted in the dataset by a ‘number’ of 0.References: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.

PURPOSE:Trawl survey data used primarily for assessing the status of snow crab stocks in the southern Gulf of St. Lawrence.DESCRIPTION:Tow, catch, and biological information for snow crab and other species caught during the annual snow crab research vessel trawl survey in the southern Gulf of St. Lawrence. Currently, the survey uses a stratified random design that divides the area into 355 square grids, each measuring 12.7 km by 12.7 km. The survey area spans the majority of snow crab habitat in the southern Gulf, at depths ranging from 20 to 200 fathoms. Sampling stations are trawled during civil twilight hours using a Bigouden Nephrops bottom trawl net. The vessel operates at a target speed of 2 knots for a duration of 5 minutes, maintaining a warp-to-depth ratio of 3:1, with a maximum warp length of 575 fathoms.PARAMETERS COLLECTED:Snow crab: sex, carapace width, height of male crab claw, shell condition, gonad colour, egg colour, eggs remaining, and missing legs.Other species: counts, and weightsOther: GPS coordinates; swept area; depth; temperature; CTD profile;NOTES ON QUALITY CONTROL:Data are checked for irregularities and errors.SAMPLING METHODS:Survey catches are sorted by species or taxonomic groups and measured directly on board. All snow crab are measured, while select fish species are measured only for a subset of survey stations.USE LIMITATION:To ensure scientific integrity and appropriate use of the data, we would encourage you to contact the data custodian.