Survey for the assessment of Unit 2 Redfish (CCGS John Cabot)
Monitoring of Unit 2 redfish by Fisheries and Oceans Canada (DFO) ceased in 2002. Since then, the Atlantic Groundfish Council (AGC, formerly the Groundfish Enterprise Allocation Council [GEAC]) has funded surveys approximately every two years in the area, in collaboration with DFO. Over the years, various vessels and gear types have been used.
In 2024, a comparative survey was conducted using the CCGS John Cabot and a fishing industry vessel (the Léry Charles) to develop conversion factors that allow data from the 2020, 2022, and 2024 Unit 2 redfish surveys to be standardized to CCGS John Cabot equivalents. The survey covered the waters off southwestern Newfoundland and eastern Cape Breton, corresponding to redfish management Unit 2, which includes NAFO subdivisions 3Pn, 3Ps, 4Vn, 4Vs, and 4W. Here, data collected aboard the CCGS John Cabot are presented.
Objectives
• Assess the abundance and condition of groundfish and invertebrates
• Assess environmental conditions
• Inventory the biodiversity of benthic and demersal megafauna
• Monitor the pelagic ecosystem
• Collect samples for various research projects
Data
The CCGS John Cabot employed a four-sided modified Campelen 1800 shrimp trawl, fitted with a Rockhopper ("bicycle") footgear. The trawl extension and codend were lined with 12.7 mm knotless nylon mesh. Standard trawl tows were 15 minutes in duration, timed from bottom contact, with a target towing speed of 3 knots.
For 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 sampled for several species such as Atlantic cod, Atlantic halibut, and Greenland halibut. Roughly 2-kg of shrimp are sorted and weighed by species. The other invertebrates are counted (no individual measurements) and photographed.
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 “Shrimps” file containing information on shrimp catches. The columns source_info, no_survey, nbpc and set_number serve as a common key linking the four datasets.
It is 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. Data is available from 1997-2022 but please contact the data management team ([email protected]) for access and further details. For any other information please also contact the data management team.
Datasets available for download
Additional Info
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| Last Updated | October 20, 2025, 02:26 (UTC) |
| Created | October 20, 2025, 02:26 (UTC) |
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Domain / Topic
Domain or topic of the dataset being cataloged.
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Biota, Environment, Oceans |
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Title
Title for the Dataset.
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Survey for the assessment of Unit 2 Redfish (CCGS John Cabot) |
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Description
A description of the dataset.
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Monitoring of Unit 2 redfish by Fisheries and Oceans Canada (DFO) ceased in 2002. Since then, the Atlantic Groundfish Council (AGC, formerly the Groundfish Enterprise Allocation Council [GEAC]) has funded surveys approximately every two years in the area, in collaboration with DFO. Over the years, various vessels and gear types have been used. In 2024, a comparative survey was conducted using the CCGS John Cabot and a fishing industry vessel (the Léry Charles) to develop conversion factors that allow data from the 2020, 2022, and 2024 Unit 2 redfish surveys to be standardized to CCGS John Cabot equivalents. The survey covered the waters off southwestern Newfoundland and eastern Cape Breton, corresponding to redfish management Unit 2, which includes NAFO subdivisions 3Pn, 3Ps, 4Vn, 4Vs, and 4W. Here, data collected aboard the CCGS John Cabot are presented. Objectives • Assess the abundance and condition of groundfish and invertebrates • Assess environmental conditions • Inventory the biodiversity of benthic and demersal megafauna • Monitor the pelagic ecosystem • Collect samples for various research projects Data The CCGS John Cabot employed a four-sided modified Campelen 1800 shrimp trawl, fitted with a Rockhopper ("bicycle") footgear. The trawl extension and codend were lined with 12.7 mm knotless nylon mesh. Standard trawl tows were 15 minutes in duration, timed from bottom contact, with a target towing speed of 3 knots. For 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 sampled for several species such as Atlantic cod, Atlantic halibut, and Greenland halibut. Roughly 2-kg of shrimp are sorted and weighed by species. The other invertebrates are counted (no individual measurements) and photographed. 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 “Shrimps” file containing information on shrimp catches. The columns source_info, no_survey, nbpc and set_number serve as a common key linking the four datasets. It is 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. Data is available from 1997-2022 but please contact the data management team ([email protected]) for access and further details. For any other information please also contact the data management team. |
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Metadata Identifier
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Published Date
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2025-08-01 |
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End date of time data in the dataset.
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License
License used to access the dataset.
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Open Government Licence - Canada |
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Limits on use
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Location
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https://open.canada.ca/data/en/dataset/d79741f7-5b02-443e-859a-7b1350ea2bff |
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Data Service
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Owner
Owner of the dataset.
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Fisheries and Oceans Canada | Pêches et Océans Canada |
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Contact Point Email
The email to contact regarding access?
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Publisher
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Publisher Email
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[email protected] |
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Author
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Author Email
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Accessed At
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Identifier
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Contains data about individuals
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Contains data about identifiable individuals
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Contains Indigenous Data
Does the data hold data about Indigenous communities?
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Platform type of the source portal.
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Version
Version of the datatset
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None |
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Source
Source of the dataset.
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None |
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Version notes
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Is version of another dataset
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Other versions
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Provenance Text
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Provenance URL
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GeoSpatial resolution in meters
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GeoSpatial resolution (in regions)
Describes how granular (in regions) geospatial data is in the dataset.
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Indigenous Community Permission
Who holds the Indigenous Community Permission. Who to contact regarding access to a dataset that has data about Indigenous communities.
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Community Permission
Community permission (who gave permission).
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The Indigenous communities the dataset is about
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Number of data rows
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