Maritimes 4VSW Research Vessel Surveys
Citation
Regnier-McKellar C (2022). Maritimes 4VSW Research Vessel Surveys. Version 1.3. Fisheries and Oceans Canada. Sampling event dataset https://doi.org/10.15468/gw9n44 accessed via GBIF.org on 2024-12-04.Description
“4VSW” missions focus on the eastern half of the Scotian Shelf, and occur primarily in March, but sets in both February, and April are also present in the data. These missions use a unique stratification scheme intended to optimize the abundance estimates of cod. Collected data includes total catch in numbers and weights by species. Length frequency data is available for most species, as are the age, sex, maturity and weight information for a subset of the individual animals. Other data such as ageing material, genetic material, and stomach contents are often also collected, but are stored elsewhere.Sampling Description
Study Extent
“4VSW” missions focus on the eastern half of the Scotian Shelf, and occur primarily in March, but sets in both February, and April are also present in the data.Sampling
Collected data includes total catch in numbers and weights by species. Length frequency data is available for most species, as are the age, sex, maturity and weight information for a subset of the individual animals. When a trawl is hauled, all of the individuals are sorted baskets by species, and the baskets are weighed to get total biomass for a species.If we have a large catch, some baskets will be kept for detailed sampling and others will be discarded. Only a subset of these are individually weighed, thus there are some occurrences which have a length but no weight. When a trawl is hauled, all of the individuals for a given species are weighed and counted. These values become total biomass and individual count. For huge catches, the individual count is sometimes calculated from the weight. Prior to 1995, they used a spring scale for measuring total weight for a species. It recorded to the nearest kg. Small catches were entered as zero. For many species, you can see Zero as the biomass estimate throughout these years.
Prior to 2005, there are some invertebrate records, but the focus was primarily on commercial species (e.g. scallop, lobster).
The “Strong Effect” shows up in the mid-90’s when Mike Strong insisted they start sorting the sculpins and pouts more carefully and our species count went up. The standard ID guide used is Scott and Scott, Atlantic fishes of Canada, and it appeared in the late 1980’s. The guide available prior to that did not distinguish between Red Hake and White Hake. We can see this in our data. There are inconsistencies in using a separate code for Red Hake before about 1978. It does not have much impact on White Hake, which has a much higher biomass, but it does for Red Hake.
Below 40cm, winter and little skate ID is questionable.
Quality Control
Data are input while at sea using the in-house developed application Groundfish Entry System. Rigorous error checks and warnings are applied and edits take place during sampling in most cases. Further quality assurance checks are applied before loading to the production database. Scientific names associated with resource occurrence records have been mapped to recognized standards - marine taxa have been mapped to the World Register of Marine Species (WoRMS). The WoRMS codes, the AphiaIDs have been included as LSIDs in the occurrence record DwC field scientificNameID.Method steps
- To prepare this dataset for OBIS Canada publication, data was structured into an OBIS-compatible format using R and laid out in four tables: an Event Core, Occurrence Core and three Extended Measurement of Fact extensions. Defined vocabularies listed on the Natural Environment Research Council (NERC) Vocabulary Server (NVS) were used whenever possible. Taxon matches were obtained from WoRMS.
Taxonomic Coverages
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Actinopterygiicommon name: Ray-finned fishes rank: class
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Anthozoacommon name: Sea anemones/Stony Corals/Soft corals rank: class
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Ascidiaceacommon name: Ascidians/Tunicates/Sea Squirts rank: class
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Asteroideacommon name: Sea Stars rank: class
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Bivalviacommon name: Bivalve molluscs rank: class
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Cephalopodacommon name: Cephalopods rank: class
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Demospongiaecommon name: Sponges rank: class
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Echinoideacommon name: Sea Urchins rank: class
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Elasmobranchiicommon name: Sharks/Rays/Skates/etc. rank: class
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Gastropodacommon name: Snails rank: class
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Hexactinellidacommon name: Hexactinellid sponges rank: class
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Hexanaupliacommon name: Copepods/Barnacles/etc. rank: class
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Holothuroideacommon name: Sea cucumbers rank: class
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Malacostracacommon name: Crabs/Lobsters/Shrimp/Amphipods/Isopods/etc. rank: class
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Mammaliacommon name: Mammals rank: class
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Myxinicommon name: Hagfish rank: class
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Ophiuroideacommon name: Brittlestars/Basketstars/etc. rank: class
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Petromyzonticommon name: Lamprey rank: class
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Polychaetacommon name: Bristleworms/Polychaetes rank: class
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Polyplacophoracommon name: Chitons rank: class
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Pycnogonidacommon name: Sea Spiders rank: class
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Scyphozoacommon name: True jellies rank: class
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Chordatacommon name: Chordates rank: phylum
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Brachiopodacommon name: Lampshells rank: phylum
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Arthropodacommon name: Crustaceans rank: phylum
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Ctenophoracommon name: Comb Jellies rank: phylum
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Poriferacommon name: Sponges rank: phylum
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Annelidacommon name: Segmented worms rank: phylum
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Molluscacommon name: Molluscs rank: phylum
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Bryozoacommon name: Bryozoans rank: phylum
Geographic Coverages
“4VSW” missions focus on the eastern half of the Scotian Shelf
Bibliographic Citations
Contacts
Catriona Regnier-McKellaroriginator
position: Survey Biologist
Fisheries and Oceans Canada
email: Catriona.Regnier-McKellar@dfo-mpo.gc.ca
Catriona Regnier-McKellar
metadata author
position: Survey Biologist
Fisheries and Oceans Canada
email: Catriona.Regnier-McKellar@dfo-mpo.gc.ca
Catriona Regnier-McKellar
administrative point of contact
position: Survey Biologist
Fisheries and Oceans Canada
email: Catriona.Regnier-McKellar@dfo-mpo.gc.ca