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37 Datasets, Page 1 of 4
Biodiversity of the American lobster trawl survey in the Magdalen Islands
A research survey on American lobster (Homarus americanus) has been conducted annually in the Magdalen Islands since 1995 to assess the abundance and structure of lobster populations in this area. Starting in 2007, the main objective was modified to include the diversity and abundance of benthic species associated with lobster habitat. Only benthic species data associated with lobster habitat are presented in this dataset.Surveys were generally conducted during the first two weeks of September from 2007 to 2020 on the entire south side of the Magdalen Islands, from Grosse-Île to Havre-Aubert. The sampling plan consists of 70 trawl tows on 50 fixed stations, between 4 and 35 meters in depth. Some stations had double tows. Specimens were collected using a Nephrops-type door trawl with a total width of 3.04 meters consisting of four Vexar™ lined baskets of 19 millimeter mesh size in order to harvest small individuals. Start and end positions were recorded to calculate the distance traveled at each tow using the geosphere library in R. The year 2011 is not included in the dataset, as biodiversity data were not recorded. Since 2017, the average tow distance has been reduced from 1000 meters to 500 meters. The opening of the trawl is also noted every minute throughout the duration of the tow so that the area sampled can be calculated. The area covered in each tow was the product of the trawl opening and the distance traveled.The two files provided (DarwinCore format) are complementary and are linked by the "eventID" key. The "Event_data" file includes generic activity information, including date and location. The "Occurrence" file includes the taxonomy of the observed species, identified to the species or lowest possible taxonomic level. For abundance and biomass estimates, contact Benoît Bruneau (Benoit.Bruneau@dfo-mpo.gc.ca).For quality controls, all taxonomic names were checked against the World Register of Marine Species (WoRMS) to match recognized standards. The WoRMS match was placed in the "ScientificnameID" field of the occurrence file. Special cases were noted in the "identificationRemarks" field and selected specimens were confirmed with field photos mentioned in "associatedMedia". Data quality checks were performed using the R obistools and WORMS libraries. All sampling locations were spatially validated.
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
Building to Scale
A building is a structure that has a roof and walls and stands more or less permanently in one place. Small buildings have only their location recorded. A 'building to scale' is a structure that has one dimension larger than 50 metres for the 1: 20,000 scale and larger than 30 metres for the 1: 10,000 scale. Their extents are recorded. This product requires the use of geographic information system (GIS) software.
Fishermen and Scientist Research Society (FSRS) Lobster Recruitment Trap Project
The lobster recruitment project is run by the Fishermen and Scientist Research Society (FSRS) through DFO funding. Fishermen participating in the lobster recruitment project collect information about lobster in their fishing area by fishing 2-5 scientific project traps (SPTs) (fished in fixed locations) within the regular commercial season. The SPTs used in all fishing areas are smaller than commercial traps and designed to primarily catch juvenile lobsters below the legal-size limit.These traps are additional to the vessel's legal number of commercial traps. The lobster recruitment project has more than 120 fishers participating from all LFAs along the Atlantic coast of Nova Scotia from LFA 27 in Cape Breton to LFA 35 in the Bay of Fundy (excluding LFA 28, who have not participated to-date).The number of fishermen per LFA and number of SPTs per fisherman are decided on by the LFA Advisory Committees. This decision considers how much additional effort they were comfortable having in the LFA (i.e. number of SPTs) and from how many traps each fisher could be reasonably expected to collect data. It is also important to have fishers dispersed enough to maximize study footprint. DFO Science consults on project design. SAMPLING METHODS: The fishers record the number, sex and length of lobsters captured in each SPT, as well as presence of eggs, tags or v-notch. Bottom temperatures are monitored by placing a temperature recorder in one of their SPTs for the entire lobster season.Cite this data as: Tibbets-Scott, S., Zisserson, B. Data of: Fishermen and Scientist Research Society (FSRS) Lobster Recruitment Trap Project. Published: November 2020. Population Ecology Division, Fisheries and Oceans Canada, Dartmouth, N.S. https://open.canada.ca/data/en/dataset/a88f9b4d-b59a-44f6-ae7e-d36550266940
The Strait of Georgia Ichthyoplankton Survey, 1979-1981
Ichthyoplankton surveys were conducted in the Strait of Georgia (British Columbia) during 1979-1981 to ascertain the onset of fish spawning, and to explore distributional pattern and estimate total biomass of fish species.Oblique tows were made using 0.25m2 Bongos equipped with 351 micron Nitex nets of modified SCOR design. All sampling gear was black to minimize potential avoidance and resulting catch bias. The tow procedure generally followed that established by CALCOFI.This dataset contains a compilation of corrected catches of juvenile fishes, fish eggs and fish larvae by station.
NAFO fishing division 4T Herring Science Acoustic Survey
Since 1991, an annual fishery-independent acoustic survey of early fall (September-October) concentrations of Herring has been conducted in the sGSL. The standard annual survey area occurs in the 4Tmno areas where both NAFO Div. 4T Herring spawning components aggregate in the fall. The survey uses a random stratified design of parallel transects within predefined strata. Surveys are conducted at night and use two vessels: an acoustic vessel to quantify the fish schools biomass using a hull-mounted 120 KHz split-beam transducer, and a fishing vessel to sample aggregates of fish with a pelagic trawl (details in LeBlanc et al. 2015; see also LeBlanc and Dale 1996).Trawl samples are used to separate the estimated biomass by spawning component and age, determine species composition, and size distribution for the estimation of the target strength (LeBlanc and Dale 1996; LeBlanc et al. 2015).A standardized abundance index is generated from this acoustic survey. This index includes catch-at-age data since 1994.This survey also provides the age-disaggregated acoustic abundance index for ages 2 to 10 for spring spawners and fall spawners.
Benthic Megafaunal Assemblages on Scallop Fishing Grounds in the Bay of Fundy (1997 and 2007)
The annual summer scallop surveys on the principal grounds in the Bay of Fundy follow stratified-random designs. The gear comprises a ‘Digby scallop drag’ with four ‘buckets’, each of 760 mm inside width, their bags being made of 74 mm steel-wire rings linked by rubber washers. A comparative data set of three scallop grounds (Digby, Lurcher Shoal and Grand Manan) was produced comprised of 190 stations sampled in 1997 and 213 from 2007–08. Presence/absence of a common suite of 68 benthic invertebrate taxa were recorded: 43 individual species, 20 additional genera and five higher taxa, all drawn from nine phyla. Each taxon was coded for each of seven biological traits (each with associated modalities), selected for their assumed relevance to environmental drivers. A score between 0 and 3 was assigned based on the literature for the taxon’s affinity to each modality, using ‘fuzzy coding’. Non-zero scores were assigned to as many modalities as required to represent the traits of the taxon’s adult stage. The resulting taxa x traits matrix, of 68 taxa by 27 modalities, is provided here along with the metadata for each station sampled. In addition, fourteen environmental variables, deemed relevant to benthic epifauna and representing both seabed sediments and the water column, were quantified for each survey station. Seabed depth, mean grain size, mean significant wave height, mean seabed shear stress, root mean square tidal current speed 1 m above the seabed and combined averaged wave-current shear velocity were each extracted from a sediment transport model for the Bay of Fundy prepared by Li et al. (2015). Mean values for current velocities, salinity and temperature for both surface and bottom layers, plus maximum mixed layer depth and bottom shear were each drawn from the Bedford Institute of Oceanography North Atlantic Model (BNAM: Wang et al., 2018). BNAM values averaged across 1990–2015 were used when examining faunal differences among survey areas, but explorations of temporal change used annual values for 1997 and 2007 individually. The variable nomenclature in the attached spreadsheet follows those of Li et al. (2015) and Wang et al. (2018). Results of the spatial and temporal analyses of these data are found in Staniforth et al. (2023). The values for each of the environmental variables are provided in the spreadsheet below. Their interpolated surfaces are also provided.Cite this data as: MacDonald, Barry; Staniforth, Calisa; Lirette, Camille; Murillo, Francisco; Kenchington, Ellen; Kenchington, Trevor (2023). Benthic Megafaunal Assemblages on Scallop Fishing Grounds in the Bay of Fundy (1997 and 2007). Published May 2024. Ocean Ecosystems Science Division, Fisheries and Oceans Canada, Dartmouth, N.S. https://open.canada.ca/data/en/dataset/935836da-a565-4f1e-806e-d354d8db252c
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.
Mapping Inshore Lobster Landings and Fishing Effort on a Maritimes Region Statistical Grid (2015–2019)
This report describes an analysis of Maritimes Region inshore lobster logbook data reported at a grid level, including Bay of Fundy Disputed Zone data reported at the coordinate level. Annual and composite (2015–2019) grid maps were produced for landings, number of trap hauls, and the same series standardized by grid area, as well as maps of catch weight per number of trap hauls as an index of catch per unit effort (CPUE). Spatial differences in fishing pressure, landings, and CPUE are indicated, and potential mapping applications are outlined. Mapping the distribution and intensity of inshore lobster fishing activity has management applications for spatial planning and related decision support. The lack of region-wide latitude and longitude coordinates for inshore lobster effort and landings limits the utility of commercial logbook data for marine spatial planning purposes.
Fecundity of Herring in Divisions 4WX
Fecundity of Atlantic herring (Clupea harengus) was estimated within five spawning areas (German Bank, Scots Bay, Seal Island, Southern Shore Nova Scotia, and Eastern Shore Nova Scotia) in Northwest Atlantic Fisheries Organization (NAFO) areas 4WX in 2019 and 2020. The objective of this project was to describe the fecundity-at-size (weight, length, and age) relationships among spawning grounds, compare these relationships to historical fecundity-at-size relationships, and assess the influence of changes in weight-at-age and fecundity over time to the reproductive potential of a unit of spawning stock biomass.Cite this data as: Barrett T. Data of: Fecundity of Herring in Divisions 4WX. Published: September 2021. Population Ecology Division, Fisheries and Oceans Canada, St. Andrews, N.B. https://open.canada.ca/data/en/dataset/e39b1318-c9f7-4686-b5e5-7d838c8ac99a
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