Home /Search
Search datasets
We have found 58 datasets for the keyword "crabes". You can continue exploring the search results in the list below.
Datasets: 105,254
Contributors: 42
Results
58 Datasets, Page 1 of 6
Scientific surveys on the snow crab (Chionoecetes opilio) in the estuary and northern Gulf of St. Lawrence
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 Area Response Planning Pilot Areas
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
Inshore Lobster Trawl Survey
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.
Snow Crab Collaborative Post-season Trap Survey
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
Seasonal temperature and salinity of Petite baie Saint-Nicolas (Godbout) in Gulf of St Lawrence from August 2019 to October 2021
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.
Northumberland Strait Multi-species Trawl Survey Data
PURPOSE:The primary objective of this survey is to obtain an index of the abundance and biomass of American lobster (Homarus americanus) in the Northumberland Strait. This research survey also provides fisheries-independent information for all of the species captured by the trawl.DESCRIPTION:Catch weight, length frequencies, and biological information for crustaceans and fish caught during the annual July-August research vessel trawl survey in Northumberland Strait (NAFO Division 4T). Abundance indices and spatial distribution patterns of commercial and non-commercial crustaceans and other groundfish. PARAMETERS COLLECTED:The full catch is sorted to species, or lowest taxonomic group possible, and weighed. For lobster, carapace length, sex and carapace condition (i.e. stage of moult) are recorded. For female lobster, the presence or absence of eggs is noted and, starting in 2010, the stage of development of the eggs (i.e. new or old) when present was also recorded. Similarly, for crabs, the carapace width, sex and carapace condition (i.e. stage of moult) is recorded as is the presence or absence of eggs (for females). Fish sampling varied over the years but, starting in 2005, length has been recorded for all fish captured.For large catches, the complete catch is sorted and weighed, but sub-sampling, by species, is used for the other measurements.NOTES ON QUALITY CONTROL:Data are checked for irregularities.SAMPLING METHODS:The Northumberland Strait multi-species survey began in 2001 using a stratified random sampling plan. A random selection of sampling sites within the study area is now used. Sampling is completed annually over a 4-week period in July and August. One hundred ten (110) stations are sampled in Northumberland Strait in water depths greater than 4 m at the lowest normal tide. The survey has employed a 286 Rockhopper trawl for all years from 2001 to 2018, except in 2010 and 2011, when a Nephrops trawl was used. In 2019, a new trawl (called the Northumberland trawl) was used in addition to the Rockhopper trawl. The Northumberland trawl is similar to the 286 Rockhopper trawl, but with a smaller footgear and smaller mesh sizes. At each station, the trawl is towed for a set period of time (recently 15 minutes with the rockhopper trawl and 10 minutes with the Northumberland trawl).USE LIMITATION:To ensure scientific integrity and appropriate use of the data, we would encourage you to contact the data custodian.
Scientific trawl surveys of American lobster (Homarus americanus) and rock crab (Cancer irroratus) in the Magdalene Island
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
Annual multidisciplinary survey for assessing groundfish and shrimp in the Estuary and northern Gulf of St. Lawrence (CCGS Alfred Needler 1990 - 2005)
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).
Community Aquatic Monitoring Program (CAMP) data for the Southern Gulf of St. Lawrence Dataset
Each summer, environmental community groups collect important data to determine if groupings of fish, shrimp and crab – what is called a community- can be used as an indicator of the health status of bays and estuaries. Sampling was conducted from May through September for the first years then from June through August. In 2018 and 2019, the sampling was conducted just once in each estuary. Community group members and staff sample six stations once a month in their designated estuary.Fish, shrimps and crabs are collected with a beach seine net and later released live back to the water once identified and counted. From this, the community groups provide important information to Fisheries and Oceans Canada, including:- identification and numbers of fish, shrimp and crab species;- water conditions and samples;- information on aquatic plants;- sediment samples.With this information, Fisheries and Oceans Canada scientists working with government agencies and universities can conduct analyses to determine the suitability of indicators to assess the health of bays and estuaries.PARAMETERS COLLECTED:Parameters: abundance, species richness, species developmental stage (young-of-the-year or adult), water temperature, water salinity, water dissolved oxygen, dissolved inorganic nutrient (nitrate, nitrite, phosphate), sediment % organic content, sediment % humidity content and sediment mean grain size, % submerged aquatic vegetation coverNOTES ON QUALITY CONTROL:Data entry into Excel and first quality control verification is done by CAMP summer students. A second quality control verification is done by DFO staff. See publ # 2823 attached to this record.In 2018, the historical data was migrated into a relationship database. From this year on, annual data will be entered into the database using a custom application. The application front end has numerous QC elements built-in.SAMPLING METHODS:Please see the following URL for sampling details: http://www.dfo-mpo.gc.ca/Library/319437.pdf
Snow Crab Abundance and Biomass Estimates (Commercial Crab and Mature Female) in the Southern Gulf of St. Lawrence
PURPOSE:These data have been updated following a Canadian Science Advice Secretariat (CSAS) Regional Science Advisory Process. Associated publications are available in the citation section below or will be posted on the Fisheries and Oceans Canada (DFO) Science Advisory Schedule as they become available.DESCRIPTION:Provide a record of commercial and mature female snow crab abundance and biomass in the southern Gulf of St. Lawrence. Female snow crab represents an index of reproductive stock.Snow crab in the southern Gulf are treated as a single stock in the annual assessments. Abundance and biomass estimates for the commercial and female reproductive stock are produced using kriging, a type of spatial analysis. The time series starts in 1997. USE LIMITATION:To ensure scientific integrity and appropriate use of the data, we would encourage you to contact the data custodian.
Tell us what you think!
GEO.ca is committed to open dialogue and community building around location-based issues and topics that matter to you.
Please send us your feedback