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We have found 94 datasets for the keyword "molluscs". You can continue exploring the search results in the list below.
Datasets: 106,103
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94 Datasets, Page 1 of 10
Biodiversity of the Magdalen Islands Sea Scallop survey
A research survey of scallops (mainly sea scallop Placopecten magellanicus, but also Icelandic Scallop Chlamys islandica) using a dredge was carried out by DFO (Fisheries and Oceans Canada) every 1 or 2 years since 1992 in the Magdalen Islands (fishing area 20). The main objective of this research survey was to assess Sea Scallop stocks. Another objective was to document taxa associated with scallop habitat according to a fixed random sampling plan. Occurrences for the year 2021 and 2022 are presented by species (or taxon) by station. Starting in 2021, catches were weighed, and specimens photographed, with information available upon request. The taxonomic and geographical validity of the data was checked and the World Register of Marine Species served as the taxonomic authority for naming all taxa recorded during the survey. Epibenthic invertebrates (mainly molluscs, echinoderms and crustaceans) as well as demersal fish were identified from the dredge catches. The historical dataset is available at the following link : https://open.canada.ca/data/en/dataset/71732ad5-5c70-4dbf-916d-a94e1380c53bThe study area is located south of the Magdalen Islands and the sampling of scallop beds is carried out at depths of generally around 25 to 35 m. A random selection of sampling stations is carried out from a fixed station grid. Sampling is done along transects at these randomly drawn stations in the study area. Sampling is done with a lined Digby scallop dredge (20 mm mesh) over approximately 500 m along the seabed. The four baskets of the dredge are examined for all scallops, and starting in 2022, also for all fishes. One basket (first on the starboard side) is sorted and examined for associated species. Most specimens are counted by taxa. Those that are too small and numerous, or colonial, are noted for presence or relative abundance. Special cases are occasionally conserved for taxonomic analysis, for example, ascidians (to monitor for invasive species) and sponges (to document new species). The availability of photos and some conserved specimens enables future review. Changes are anticipated in the identifications, notably for Bryozoan, Hydrozoa, and Porifera, that are currently the focus of research efforts.
Pelagic Shark Satellite Tag data - Porbeagle
The porbeagle shark (Lamna nasus), is a species found in Atlantic Canadian waters which is encountered in commercial and recreational fisheries. Pop-up Satellite Archival Tags (PSAT) from Wildlife Computers were applied to porbeagle sharks from 2005 to 2021 to collect data on depth (pressure), temperature and ambient light level (for position estimation). Deployments were conducted in Canada and the Faroe Islands on commercial, recreational and scientific charters, typically in summer and fall but some over winter when the porbeagle commercial fishery was active in Canada. A variety of tag models were deployed: PAT 4 (n=1), Mk10 (N=41), and MiniPAT (N=15) and 51 of 57 tags reported. One individual shark was recaptured and the physical tag was returned. The porbeagle sharks tagged ranged in size from 76 cm to 249 cm Fork Length (curved); 42 were female, 15 were male. Time at liberty ranged from 4 – 356 days and 14 tags remained on for the programmed duration. Raw data transmitted from the PSAT’s after release was processed through Wildlife Computers software (GPE3) to get summary files, assuming a maximum swimming speed of 2m/s, NOAA OI SST V2 High Resolution data set for SST reference and ETOPO1-Bedrock dataset for bathymetry reference. The maximum likelihood position estimates are available in .csv and .kmz format and depth and temperature profiles are also in .csv format. Other tag outputs as well as metadata from the deployments can be obtained upon request from: warren.joyce@dfo-mpo.gc.ca or heather.bowlby@dfo-mpo.gc.ca.
Blue whale - Trajectories and locations of Area-Restricted Search
The blue whale (Balaenopterus musculus) is a wide-ranging cetacean that can be found in all oceans, inhabiting coastal and oceanic habitats. In the North Atlantic, little is known about blue whale distribution and genetic structure, and if whether animals found in Icelandic waters, the Azores, or Northwest Africa are part of the same population as those from the Northwest Atlantic. In the Northwest Atlantic, seasonal movements of blue whales and habitat use, including the location of breeding and wintering areas, are poorly understood.The behaviour of remotely-monitored animals can be inferred from a time series of location data. This is because animals tend to demonstrate stochasticity in their movement paths as a result of spatial variation in environmental characteristics, such as topography or prey density (Curio 1976; Gardner et al. 1989; Turchin 1991; Wiens et al. 1993). Predators are expected to decrease travel speed and/or increase turning frequency and turning angle when a suitable resource, e.g., food patch, is encountered (Turchin 1991), otherwise known as area-restricted search (ARS). In contrast, animals in transit or travelling tend to move at faster and more regular speeds, with infrequent and smaller turning angles (Kareiva and Odell 1987; Turchin 1998).Based on satellite telemetry to track the seasonal movements of 24 blue whales from eastern Canada in 2002 and from 2010 to 2015, it was possible to estimate trajectories and locations where ARS behaviour of blue whales was inferred at a 4h time interval.To assess blue whale movements and behavior, a Bayesian switching statespace model (SSSM) was applied to Argos-derived telemetry data (Jonsen et al. 2005; Jonsen et al. 2013). An SSSM essentially estimates animal location at fixed time intervals, movement parameters and behavioral patterns.Two important sources of uncertainty can be measured separately: estimation error resulting from inaccurate observations (Argos location error) and process variability linked to the stochasticity of the movement process (behavior mode estimation) (Jonsen et al. 2003; Patterson et al. 2008).The points visible on land are the result of errors in the Argos geographic position calculation. They have been deliberately left unchanged to assess the performance of the model, which was able to clean up some positions, but not all.Lesage, V., Gavrilchuk, K., Andrews, R.D., and Sears, R. 2016. Wintering areas, fall movements and foraging sites of blue whales satellite-tracked in the Western North Atlantic. DFO Can. Sci. Advis. Sec. Res. Doc. 2016/078. v + 38 p.
Pelagic Shark Satellite Tag data - Basking Shark
The basking shark (Cetorhinus maximus), is a species found in Atlantic Canadian waters which is mostly encountered “basking” on the surface waters and sometimes caught accidentally in commercial fisheries. One Pop-up Satellite Archival Tag (PSAT Mk10) from Wildlife Computers was applied to a single female basking shark in September 2008 on a commercial vessel to collect data on depth (pressure), temperature and ambient light level (for position estimation). The basking shark was 610 cm Total Length (curved). The tag released on the pre-programmed date 125 days after deployment. Raw data transmitted from the PSAT’s after release was processed through Wildlife Computers software (GPE3) to get summary files, assuming a maximum swimming speed of 2m/s, NOAA OI SST V2 High Resolution data set for SST reference and ETOPO1-Bedrock dataset for bathymetry reference. The maximum likelihood position estimates are available in .csv and .kmz format and depth and temperature profiles are also in .csv format. Other tag outputs as well as metadata from the deployment can be obtained upon request from: warren.joyce@dfo-mpo.gc.ca or heather.bowlby@dfo-mpo.gc.ca.
Pelagic Shark Satellite Tag data - White Shark
The white shark (Carcharodon carcharias), is a species found in Atlantic Canadian waters which is encountered in commercial and recreational fisheries. Pop-up Satellite Archival Tags (PSAT) from Wildlife Computers were applied to white sharks from 2016 to the present to collect data on depth (pressure), temperature and ambient light level (for position estimation). Deployments were conducted in Canada and the United States (Cape Cod and South Carolina) on scientific charters, typically in summer. Tag models deployed included: Mk10 (N=1), and MiniPAT (N=29) and 22 of 27 tags reported with 3 still at liberty. One individual shark returned to the location of tagging 1 year later and the physical tag was recovered. Another tag was recovered 5 years after deployment. White sharks tagged ranged in size from 259 cm to 459 cm Total Length (curved) estimated; 15 were female, 13 were male, and 2 were of unknown sex. Time at liberty ranged from 48 – 377 days and to date, only 3 tags remained on the shark for the programmed duration. Tagging of white sharks is an ongoing study and data will be updated here when it becomes available. Raw data transmitted from the PSAT’s after release was processed through Wildlife Computers software (GPE3) to get summary files, assuming a maximum swimming speed of 2m/s, NOAA OI SST V2 High Resolution data set for SST reference and ETOPO1-Bedrock dataset for bathymetry reference. The maximum likelihood position estimates are available in .csv and .kmz format and depth and temperature profiles are also in .csv format. Other tag outputs as well as metadata from the deployments can be obtained upon request from: warren.joyce@dfo-mpo.gc.ca or heather.bowlby@dfo-mpo.gc.ca.
Blue Whale - High density feeding areas
11 tagged Blue whales (Balaenoptera musculus) were tracked during the daytime movements as well as the feeding behaviour in the St. Lawrence River estuary. Kernel density was applied to derminate the high density feeding areas of all individuals combined (30, 40, 50, 60, 75, 95 %).Doniol-Valcroze T, Lesage V, Giard J, Michaud R, 2012. Challenges in marine mammal habitat modelling: evidence of multiple foraging habitats from the identification of feeding events in blue whales. Endang Species Res, Vol. 17 : 255–268, doi : 10.3354/esr00427(English version only)
Development of a coastal species characterization approach using environmental DNA (eDNA) using the marker COI
Species characterization by environmental DNA (eDNA) is a method that allows the use of DNA released into the environment by organisms from various sources (secretions, faeces, gametes, tissues, etc.). It is a complementary tool to standard sampling methods for the identification of biodiversity. This project provides a list of invertebrates species whose DNA has been detected in water samples collected at 2018 using the marker COI.The surveys were carried out in the summer of 2018 from August 11 to 14, between Forestville and Godbout (Haute-Côte-Nord). Sampling was carried out between 9-52 meters depth in 40 stations with one sample par station. Two liters of water were filtered through a 1.2 µm fiberglass filter. DNA extractions were performed with the DNeasy Blood and Tissue extraction kit (Qiagen). Negative field, extraction and PCR controls were added at the different stages of the protocol. Libraries at the COI locus were prepared by Genome Quebec and sequenced on an Illumina MiSeq PE250 system. The bioinformatics analysis of the sequences obtained was carried out using an in-house analysis pipeline as reported in Bourret et al. 2022. A first step made it possible to obtain a molecular operational taxonomic unit table (MOTU) using the cutadapt software for the removal of the adapters and the DADA2 R package for the filtration, fusion, chimera removal and data compilation. The MOTUs table was subsequently corrected by taking into account the negative controls, where the number of observations in the latter was removed from the linked samples. Singleton MOTUs have also been removed. Finally, the taxonomic assignments were carried out on the MOTUs using the IDTAXA classifier (present in the DECIPHIER R package) using a training set trained on the COI reference bank for Golf St-Laurent (GSL-rl v1.0, https://github.com/GenomicsMLI-DFO/MLI_GSL-rl) and a threshold of 40. Detections with an “Unreliable due to gaps” category were reported at the genus level only.The file provided includes generic activity information, including site, station name, date, marker type, assignment types used for taxa identification, and a list of taxa or species. The list of taxa has been verified by a biodiversity expert from the Maurice-Lamontagne Institute.This project was funded by Fisheries and Oceans Canada's Coastal Environmental Baseline Data Program under the Oceans Protection Plan. This initiative aims to acquire baseline environmental data that contributes to the characterization of significant coastal areas and supports evidence-based assessments and management decisions to preserve marine ecosystems.Data are also available on SLGO platform : https://doi.org/10.26071/ogsl-cd4c205b-f63b
Steller Sea Lion Haulout Counts in British Columbia
The Steller sea lion (Eumetopias jubatus) is the largest species of sea lion with males weighing as much as 1,100 kg and females as much as 350 kg. In Canada, the Steller can be spotted along the rocky coast of British Columbia (BC). These highly mobile marine mammals typically travel alone or in small groups, but they congregate in large numbers at traditional rookeries and haul-outs during the mating and pupping season. Females generally live longer (up to 30 years) than males (usually up to 20 years). The population was severely depleted in Canada but following its protection in 1970, the size of the adult population has more than doubled.Trends in the abundance of Steller sea lions in BC have been assessed based on a series of standardized, province-wide aerial surveys conducted during the breeding season (27-June to 06-July) between 1971 and 2021. Additional ad-hoc surveys during the fall, winter, and spring periods were completed to assess sea lion distribution outside of the breeding season. Surveys targeted historically occupied rookeries and haul-out sites with nearby areas also monitored for potential shifts in distribution.Both datasets contain counts that have been collected from sightings of individuals from 1971 through 2021. The updated standard breeding season survey counts data file consolidates and extends two previous datasets – one covering 1971 through 2013 and the other covering the summer portion of the 2016/2017 surveys. The non-breeding season count data was previously limited to the fall-winter portion of the 2016/2017 surveys and the updated data covers the entire study period to date.
Operophtera brumata
Historical finds of Operophtera brumata
Distribution of Gray Whales - Coastal Resource Information Management System (CRIMS)
Modeled data showing the likely distribution of gray whales. CRIMS is a legacy dataset of BC coastal resource data that was acquired in a systematic and synoptic manner from 1979 and was intermittently updated throughout the years. Resource information was collected in nine study areas using a peer-reviewed provincial Resource Information Standards Committee consisting of DFO Fishery Officers, First Nations, and other subject matter experts. There are currently no plans to update this legacy data.
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