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We have found 190 datasets for the keyword "beam trawl". You can continue exploring the search results in the list below.
Datasets: 104,195
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190 Datasets, Page 1 of 19
Shrimp catch and bycatch estimates from trawling and trapping in Clio Channel, British Columbia
These data sets provide information pertaining to shrimp and bycatch estimates associated with beam-trawling and trapping (2001-2002) in Clio Channel. Data sets were compiled and formatted by Meagan Mak.Abstract from report:As part of a project investigating possible modification of marine ecosystems by shrimp trawling and trapping, we enumerated beam trawl and prawn trap catches at two locations in Clio Channel, south -central coast of British Columbia. Beam trawl surveys were conducted in Bones Bay and Turnour Bay during October 2001 and January 2002, respectively, and a prawn trap survey was conducted in Turnour Bay during March 2002. Catch data from the two gear types are presented.
Fish and invertebrate assemblages in coastal areas of the St. Lawrence Estuary (north shore) sampled with a beam trawl
This dataset derives from a series of beam trawl tows conducted during several research surveys in coastal areas of the St. Lawrence Estuary, between Portneuf-sur-Mer and Pointe-des-Monts, and between June and October of 2019, 2020, 2021 and 2022. It contains catch data for fish and invertebrates (occurrence and catch weights by species), in trawl tows conducted at depths ranging from 10 to 50 meters. Data were collected in various cruises:• June 28th to July 5th 2019 (NGCC Leim)• September 30th to October 9th 2019 (NGCC Leim)• October 1st to October 10th 2020 (NGCC Leim)• April 22nd to May 5th 2021 (NGCC Perley)• October 15th to October 24th 2021 (NGCC Perley)• June 24th to July 15th 2022 (NGCC LEIM)The beam trawl used to generate this data set consists of a frame (width of 2.8 m, height of 0.8 m) equipped with a 6.5 m long net with 40 mm diamond mesh, which is lined with a net (skirt) of square mesh (5 mm) at the cod-end (length 2 m) and a protective apron (75 mm mesh) on the ventral portion. Three skid chains are linked at the base of the skates. Each station corresponds to a 5 to 10 minutes tow along an isobath at a speed of about 2 knots. At each haul, the trawl catch was placed on a sorting table on the deck and the organisms were sorted and identified at the best possible taxonomic resolution. Most taxa were independently weighed. Some invertebrates taxa were subsampled, counted and weighted in order to estimate their contribution (weight and number) to the total catch. Additionally, the first 30 fish of each species were measured and weighed individually.Taxonomic names were verified on the World Register of Marine Species (WoRMS) to match recognized standards. The WoRMS match has been put in the scientificNameID field in the occurrence file. Data quality control was performed using the R packages obistools and worrms. All sampling locations were plotted on a map to perform a visual check confirming that the latitude and longitude coordinates were within the described sampling area. Data acquired during the research surveys additionally included: 1) occurrence data on epibenthic invertebrates and submerged aquatic vegetation in photo samples from a drop camera system, 2) occurrence data on fish and invertebrate taxa in video samples collected using a baited underwater video system (BUV), 3) substrate classification based on drop camera photo samples, 4) oceanographic measurements of the water column from Seabird 19plus V2 profiling CTD (conductivity, temperature, depth, photosynthetic active radiation, pH, dissolved oxygen), 5) nutrients (NO2, NO3, NH4, PO4, SiO3) and dissolve organic carbon (DOC) concentrations, and 6) current speed and direction from tilt meters. The first two items are available as independent data on the OBIS portal. To obtain data from items 3-6 and/or biological data collected on fish and invertebrate taxa, please contact David Lévesque or Marie-Julie Roux.The research surveys were undertaken by the Department of Fisheries and Oceans Canada as part of the baseline program of the Ocean Protection Plan. This initiative aimed to acquire environmental baseline data contributing to the characterization of important coastal areas and in support of evidence-based assessments and management decision-making for preserving marine ecosystems.Which contribute to the elaboration of conservation objectives based on an ecosystem assessment approach for fishery stock assessment requires the development of sampling methods to maximize the data collection on the ecosystem, while minimizing the impact on organisms and the marine environment. This project aims at characterising the coastal ecosystem of the St. Lawrence Estuary between Portneuf-sur-Mer and Godbout (QC), including the physico-chemistry of water, phytoplankton, zooplankton, submerged vegetation, benthic habitats as well as assemblages of fish and invertebrates. Sampling was performed by combining conventional methods such as CTD profiling, zooplankton nets, and beam trawl, with non-extractive methods such as dropped photo cameras and stereoscopic baited video camera systems. The data collected will help define baseline ecosystem conditions in the study area; explore the links between environmental conditions, habitat structure and biological assemblages; identify important habitats for marine species; as well as the evaluation of the performance of visual sampling methods compared to conventional methods. The results will make it possible to optimize the seasonal or annual monitoring in order to better understand the direct and indirect effects of human activities in coastal environments.This project was funded by the Department of Fisheries and Oceans Canada as part of the baseline program of the Ocean Protection Plan.
Ocean Salmon Program - Ricker Beam Trawl Juvenile Salmon Study from 1990 to 1993
During the period of 1990 to 1993, Robin J. LeBrasseur and N. Brent Hargreaves led a juvenile salmon migration research project off the west coast of Vancouver Island BC. This included the development of surface beam trawl gear that could be deployed from a large trawl vessel (CCGS W.E. Ricker) and operated in an offshore environment. This dataset contains the research survey catch data and individual fish examinations data.
Characterization of sediment and faunal attributes of Simoom Sound, British Columbia
These datasets provide information pertaining to sediment grain size, porosity, organic content, total carbon and nitrogen concentrations, trace element concentrations, chlorophyll and phaeopigment concentrations, and meiofauna and macrofaunal abundance in Simoom Sound between November, 2000, and February, 2001. Data formatting of files were performed by Meagan Mak.Sutherland et al (2023) covers the benthic component of a broader project investigating potential modification of marine ecosystems by shrimp trawling and trapping on the central coast of British Columbia. Sediment and infaunal samples were collected before and after fishing with commercial fishing gear consisting of otter-trawl, beam-trawl, and trap-lines. Simoom Sound was sampled in November 2000 and February 2001. Tabulated data of sediment characteristics that include sediment grain size, porosity, carbon and nitrogen content, trace-element, and chlorophyll concentrations are presented in this report. In addition, the infaunal data are comprised of both macrofaunal and meiofaunal communities.
Fish and large decapods in eelgrass (Zostera marina) beds on the Atlantic coast of Nova Scotia, Canada
Nekton assemblages in Zostera marina beds and adjacent bare soft-sediments were sampled on the south and eastern shore of Nova Scotia. Sampling gear used were visual snorkel transects and a benthic beam trawl. Fish were identified and size either measured (trawl) or estimated in situ (snorkel transects). Surveys were conducted in mid-July to Aug in summer of 2013 and 2014 across multiple sampling sites. Multiple replicate transects were conducted at each site. Raw abundances from observations were transformed into young of year (YOY) equivalent abundance, and then into density of each species calibrated to account for the sampling equipment and day/night differences.Cite this data as: Wong, M. C. Data of: Fish and large decapods in eelgrass (Zostera marina) beds on the Atlantic coast of Nova Scotia, Canada. Published: April 2020. Coastal Ecosystems Science Division, Fisheries and Oceans Canada, Dartmouth, N.S. https://open.canada.ca/data/en/dataset/dbc56f11-4a97-45e7-99f4-71966b51630c
Pelagic Fish Trawl Survey of Lake Winnipeg
To better understand patterns of temporal and spatial variation of fish assemblages in offshore waters of Lake Winnipeg (Manitoba, Canada), pelagic trawl tows were conducted at lakewide monitoring stations since 2002. Trawl samples collected during spring, summer, and fall from the south basin, channel, and north basin were used to study effects of season and geographic region within the lake on species biomass estimates.
Estimates of shrimp and fish on trawling transects at the seafloor of Bones Bay and Turnour Bay
These data sets provide information pertaining to epifauna taxa including bottom-dwelling shrimp and fish along trawling transects in Bones Bay and Turnour Bay between 2001 and 2002. Data sets were compiled and formatted by Meagan Mak.Abstract from the report:This study is a component of a larger project designed to assess potential effects of shrimp trawling gear on epifauna, shrimp, fish, and benthic habitat of Clio Channel located in Broughton Archipelago, British Columbia, Canada. Replicate beam-trawl surveys were carried out on individual transects in both Bones Bay and Turnour Bay located in the northern and southern portions of Clio Channel, respectively. A submersible, towed video-camera surveyed the seabed to enumerate epifauna and fish taxa before and after trawling activities. In regards to the video surveys, fish and epifauna (e.g. common shrimp) were observed across Clio Channel, while sea whips were predominate in the Turnour Bay video transects.
Biodiversity of the Benthic Epifauna Trawl Survey from CBS-MEA program (2021-2024)
This dataset documents the epifauna occurrences collected from 2021 to 2024 during the Canadian Beaufort Sea Marine Ecosystem Assessment (CBS-MEA) conducted by the Department of Fisheries and Oceans (DFO). This scientific program focuses on the integration of oceanography, food web linkages, physical-biological couplings, and spatial and interannual variabilities. The program also aims to expand the baseline coverage of species diversity, abundances, and habitat associations in previously unstudied areas of the Beaufort Sea and Western Canadian Archipelago. The study took place mainly in the Canadian Beaufort Sea and the Amundsen Gulf. Sampling is done along transects at fixed stations in the study area. Catches are collected with a 3 m benthic beam trawl for 10 minutes bottom-contact time at a target speed of 2 knots and with a modified Atlantic Western IIA otter trawl for 20 minutes bottom-contact time at a target speed of 2.9 knots. A total of 32 stations were sampled for epifauna in 2021, 22 in 2022, 23 in 2023 and 22 in 2024, between 22-655 m depth. Epibenthic invertebrates were identified to the lowest taxonomic level possible and photographed. All unknown specimens are frozen. In the lab, the identifications are validated or refined with the photos and the frozen specimens.The data are presented in Darwin Core and are separated in two files:The "Activité_épifaune_CBSMEA_epifauna_event_en" file which contains information about missions, stations and deployments, which are presented under a hierarchical activity structure.The "Occurrence_épifaune_CBSMEA_epifauna_en" file that contains the taxonomic occurrences.
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.
Diversity, Richness, and Biomass Hotspots
This geodatabase includes hotspot maps of 1) nearshore habitat richness, 2) diversity (fish and invertebrates), and 3) biomass (using catch per unit effort of fish and invertebrates), as well as two layers showing the spatial extent of the diversity and biomass hotspot analyses. Full details and methods can be found in the Rubidge et al. 2018 CSAS Research Document 2018/053 available here or at https://waves-vagues.dfo-mpo.gc.ca/Library/40759842.pdf. These data were reviewed as part of a Canadian Science Advisory Secretariat (CSAS) regional peer review process on Nov 1-2, 2017.Habitat Richness Hotspots: Because there are no systematic surveys of nearshore species that span the entire coastline of Northern Shelf Bioregion, the nearshore habitat richness hotspots were developed as a proxy for species diversity in nearshore areas. Habitat richness was calculated from eight habitat features: eelgrass, surfgrass, canopy-forming kelp, estuaries, areas of high rugosity, and hard, mixed, and soft substrate. The number of features within 1 km x 1 km planning units was counted, and hotspots were identified using the Getis-Ord G* tool in ArcGIS. Planning units with Gi_Bin values of 3 (99% confidence) were classified as habitat richness hotspots.Diversity and Biomass Hotspots: Hotspots of fish and invertebrate diversity and biomass were developed as proxies for spatial patterns of productivity in the Northern Shelf Bioregion. Diversity (Shannon diversity) and biomass (kg/hour or count/hook/hour) were calculated from DFO synoptic trawl and outside hard-bottom longline (HBLL) survey catch records. The outside HBLL survey was previously referred to as Pacific Halibut Management Area (PHMA) survey. The synoptic trawl and HBLL surveys have complementary spatial coverage, with the HBLL surveys occurring in more coastal areas (20–260 m) and the synoptic trawl surveys occurring on deeper shelf areas (50–1300 m). Hotspots were identified using the Getis-Ord G* tool in ArcGIS for five separate analyses: fish biomass (trawl), fish diversity (trawl), fish diversity (longline), invertebrate biomass (trawl), and invertebrate diversity (trawl). Using the Minimum Bounding Geometry Tool, convex hull polygons were drawn around groups of hotspot points (Gi_Bin values of 1, 2, or 3; confidence ≥90%) containing 10 or more points. The resulting polygons were then buffered by 1 km and manually edited where needed to exclude any large areas of the polygons that did not include hotspot points.
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