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143 Datasets, Page 1 of 15
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.
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.
Northumberland Strait Multi-species Trawl Survey Data
PURPOSE:The primary objective of this survey is to obtain an index of the abundance 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 as a random stratified survey and now employs a random selection of sampling sites within the study area. Sampling is completed annually over a 4-week period in July and August. 110 stations are sampled in Northumberland Strait in water depths exceeding 4 m at Lowest Normal Tide. The survey has employed a 286 rockhopper trawl in all years from 2001 to 2018, except in 2010 and 2011 when a Nephrops trawl was used. In 2019, a newly designed trawl (termed the “Northumberland trawl”) was used in addition to the rockhopper trawl. The Northumberland trawl is similar to the 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.
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.
Strait of Georgia Synoptic Bottom Trawl Survey
Catch, effort, location (latitude, longitude), relative abundance indices, and associated biological data from groundfish multi-species bottom trawl surveys in Strait of Georgia.IntroductionThe Strait of Georgia (SOG) synoptic bottom trawl survey was conducted in 2012 and 2015. This survey is one of a set of long-term and coordinated surveys that together cover the continental shelf and upper slope of most of the British Columbia coast. The other surveys are the Queen Charlotte Sound (QCS) survey, the Hecate Strait (HS) survey, the West Coast Vancouver Island (WCVI) survey and the West Coast Haida Gwaii (WCHG) survey. The survey was not impacted by the COVID-19 pandemic. The objectives of these surveys are to provide fishery independent abundance indices of all demersal fish species available to bottom trawling and to collect biological samples of selected species. The surveys follow a random depth-stratified design and the sampling units are 2 km by 2 km blocks. The synoptic bottom trawl surveys are conducted by Fisheries and Oceans Canada (DFO) in collaboration with the Canadian Groundfish Research and Conservation Society (CGRCS), a non-profit society composed of participants in the British Columbia commercial groundfish trawl fishery. The Queen Charlotte Sound and West Coast Haida Gwaii surveys are conducted under collaborative agreements, with the CGRCS providing chartered commercial fishing vessels and field technicians, while DFO provides in-kind contributions for running the surveys including personnel and equipment. The Hecate Strait, West Coast Vancouver Island, and Strait of Georgia surveys are conducted by DFO and have typically taken place on a Canadian Coast Guard research vessel. Until 2016 this vessel was the CCGS W.E. Ricker. From 2021 onwards, this vessel was the CCGS Sir John Franklin. In years when a coast guard vessel has not been available, the Hecate Strait, West Coast Vancouver Island, and Strait of Georgia surveys have taken place on chartered industry vessels. Data from these surveys are also presented in the groundfish data synopsis report (Anderson et al. 2019).EffortThis table contains information about the survey trips and fishing events (trawl tows/sets) that are part of this survey series. Trip-level information includes the year the survey took place, a unique trip identifier, the vessel that conducted the survey, and the trip start and end dates (the dates the vessel was away from the dock conducting the survey). Set-level information includes the date, time, location, and depth that fishing took place, as well as information that can be used to calculate fishing effort (duration) and swept area. All successful fishing events are included, regardless of what was caught.CatchThis table contains the catch information from successful fishing events. Catches are identified to species or to the lowest taxonomic level possible. Most catches are weighed, but some are too small (“trace” amounts) or too large (e.g. very large Big Skate). The unique trip identifier and set number are included so that catches can be related to the fishing event information (including capture location).BiologyThis table contains the available biological data for catches which were sampled. Data may include any or all of length, sex, weight, age. Different length types are measured depending on the species. Age structures are collected when possible for species where validated aging methods exist and are archived until required for an assessment; therefore, all existing structures have not been aged at this time. The unique trip identifier and set number are included so that samples can be related to the fishing event and catch information.BiomassThis table contains relative biomass indices of species that have been captured in every survey of the time series. The coefficient of variation and bootstrapped 95% confidence intervals are provided for each index. The groundfish data synopsis report (Anderson et al. 2019) provides an explanation of how the relative biomass indices are derived.
NAFO Division 4T Sentinel Trawl Survey Data
PURPOSE:Since 2003, a standardized otter trawl survey was conducted in August by commercial fishing vessels throughout the southern Gulf of St. Lawrence (NAFO Division 4T). The primary objective of this survey is to obtain abundance indices for the major commercial groundfish resources in the area.DESCRIPTION:Tow, catch, and length frequency for fish caught during the August sentinel surveys in the southern Gulf of St. Lawrence (NAFO Division 4T). Abundance indices and spatial distribution patterns of commercial groundfish.Note: Due to delays caused by logistic complexities and Covid, the project did not take place in 2020 PARAMETERS COLLECTED:Abundance estimates (ecological); distribution (ecological); species counts (ecological); gear (fishing); vessel information (fishing); point (spatial).NOTES ON QUALITY CONTROL:Scientific names listed in the survey species list have been mapped to recognized standards - marine taxa have been mapped to the World Register of Marine Species (WoRMS) using their online taxon match tool. 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.SAMPLING METHODS:For additional information on the sampling methods and supporting literature, please refer to the references providedUSE LIMITATION:To ensure scientific integrity and appropriate use of the data, we would encourage you to contact the data custodian.
Biodiversity of the snow crab trawl survey in Ste-Marguerite Bay, in the Gulf of St-Lawrence (2006-2009)
A research survey on snow crab (Chionoecetes opilio) was conducted from May 2006 to May 2009 in the Bay of Ste. Marguerite near Sept-Îles, Quebec. The main objective of this survey was to assess the abundance of snow crab and benthic species associated with snow crab habitat. Only data for benthic species associated with snow crab habitat are presented in this dataset.Data were collected according to a fixed station sampling design consisting of 79 stations, between 7 to 198 meters depth. Specimens were collected using a beam trawl. The codend was lined with a small stretched mesh net in order to harvest the small individuals. The hauls were made at a target duration of 15 minutes. Start and end positions were recorded to calculate the distance traveled on each tow using the geosphere library in R. The two files provided (DarwinCore format) are complementary and are linked by the "eventID" key. The "Activity_Information" file includes generic activity information, including date and location. The "occurrence_taxon" file includes the taxonomy of the species observed, identified to the species or lowest possible taxonomic level. To obtain the abundance and biomass assessment, contact Bernard Sainte-Marie (Bernard.Sainte-Marie@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. Data quality checks were performed using the R obistools and worrms libraries. All sampling locations were spatially validated.
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.
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.
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.
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