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We have found 86 datasets for the keyword " bristle worms". You can continue exploring the search results in the list below.
Datasets: 106,493
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86 Datasets, Page 1 of 9
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.
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.
Biodiversity of the snow crab trawl survey in the St. Lawrence Estuary (2019)
A research survey on snow crab (Chionoecetes opilio) was conducted from July 7 to July 26, 2019 in the Estuary St. Lawrence River between Forestville, Baie-Comeau and Matane. 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 66 stations, between 31 and 279 meters depth. Specimens were collected using a beam trawl with a total width of 2.8 meters and a total height of 0.76 meters. The codend was lined with a 16 millimeter stretched mesh net in order to harvest the small individuals. The hauls were made at a target speed of 2 knots and 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 average tow distance was approximately 25 m. The area covered at 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 "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 Cedric Juillet (cedric.juillet@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.
Biodiversity of the Stimpson's surfclam hydraulic dredge survey in the St. Lawrence Estuary (2017)
A research survey on Stimpson's surfclam (Mactromeris polynyma) was conducted from June 15 to June 26 2017 in the Estuary of the St. Lawrence River on the Forestville deposit (Fishing Area 1A). The primary objective of this survey was to investigate the spatial distribution of pre-commercial (< 80 mm) and commercial (≥ 80 mm) sizes of Stimpson's surfclams as well as to assess the abundance and diversity of benthic species associated with the sandy habitat of the Stimpson's surfclam. Only benthic species data associated with Stimpson's surfclam habitat are presented in this dataset.Data were collected according to a systematic sampling design consisting of 77 stations, between 7 and 45 m depth. Stations were spaced 200 m apart and dispersed along a total of 18 transects perpendicular to the bathymetry. Transects were parallel and spaced 500 m apart. Specimens were collected using a hydraulic dredge of the "New England" type with a total length of 2.29 meters and a total width of 1.68 meters, of which 1.35 meters was knife width. The dredge was lined with a 19 millimeter mesh Vexar™ to harvest small individuals. The hauls were made at a speed of 0.2-0.3 knots for a duration of 2 to 3 minutes. Start and end positions were recorded to calculate the distance traveled at each tow using the geosphere library in R. The average tow distance was approximately 25 m. The area covered at each stroke was the product of the width of the dredge blade and the distance.The three files provided (DarwinCore format) are complementary and are linked by the "eventID" key. The "event_information" file includes generic event information, including date and location. The "additional_information_event_and_occurrence" file includes sample size, sampling protocol and sampling effort, among others. The "taxon_occurrence" file includes the taxonomy of the species observed, identified to the species or lowest possible taxonomic level. For abundance and biomass estimates, contact Virginie Roy (virginie.roy@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 "identificationRemarks" and selected specimens were confirmed using field photos. Data quality checks were performed using the R obistools and worrms libraries. All sampling locations were spatially validated.
Biodiversity of the snow crab trawl survey on the Lower North Shore of the Gulf of St. Lawrence (2018)
A research survey on snow crab (Chionoecetes opilio) was conducted from July 1 to July 17, 2018 on the Lower North Shore of the Gulf of St. Lawrence between Havre-Saint-Pierre and Blanc-Sablon. 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 61 stations, between 46 and 230 meters depth. Specimens were collected using a beam trawl with a total width of 2.8 meters and a total height of 0.76 meters. The codend was lined with a 16 millimeter stretched mesh net in order to harvest the small individuals. The hauls were made at a target speed of 2 knots and a target duration of 10 minutes depending on seabed conditions. Start and end positions were recorded to calculate the distance traveled on each tow using the geosphere library in R. The average tow distance was approximately 25 m. The area covered at 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 "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 Cedric Juillet (cedric.juillet@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 "ScientificIDname" field of the occurrence file. Special cases were noted in the "commentsIdentification" field and selected specimens were confirmed with field photos. Data quality checks were performed using the R obistools and Worms libraries. All sampling locations were spatially validated.
Biodiversity of the whelk (Buccinum) dredge survey in the St. Lawrence Estuary
A research survey on the common whelk (Buccinum undatum) has been conducted biennially in three sectors of the St. Lawrence Estuary since 2005 to assess the abundance of whelk and benthic species associated with whelk habitat. Only data for benthic species associated with whelk habitat are presented in this dataset. The survey was initiated in 2005 following the intensive fishery of the early 2000s in the Upper North Shore region. The three sectors covered by the survey were based on the distribution of commercial fishing effort from 2001 to 2004.Surveys were conducted between mid-July and early August from 2005 to 2019 on the North Shore of the St. Lawrence Estuary between Portneuf-sur-Mer and Baie-Comeau according to a fixed station sampling design. Three sectors were surveyed at each survey: Forestville (69°03'11"W-48°39'24"N and 68°56'02"W-48°46'16"N), Pointe-aux-Outardes (68°35'53"W-48°59'32"N and 68°25'30"W-49°01'06"N) and Baie-Comeau (68°06'04"W-49°08'40"N and 68°05'10"W-49°12'26"N). Since 2007, the sampling plan consists of 55 stations in Forestville, 26 stations in Pointe-aux-Outardes and 11 stations in Baie-Comeau. The targeted depth interval at the three sectors was approximately 5 to 40 m. Specimens were collected using a Digby-type scallop dredge with a total width of 3.04 m consisting of four 19 mm mesh Vexar™ lined baskets to harvest small individuals. Start and end positions were recorded to calculate the distance traveled at each tow using the geosphere library in R. Since 2011, the average tow distance was approximately 300 m. The area covered at each tow was the product of the dredge width and distance.The three files provided (DarwinCore format) are complementary and are linked by the "eventID" key. The "event_information" file includes generic event information, including date and location. The "additional_information_event_and_occurrence" file includes sample size, sampling protocol and sampling effort, among others. The "taxon_occurrence" file includes the taxonomy of the species observed, identified to the species or lowest possible taxonomic level. For abundance and biomass estimates, contact Virginie Roy (virginie.roy@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 "identificationRemarks" and selected specimens were confirmed using field photos. Data quality checks were performed using the R obistools and worrms libraries. All sampling locations were spatially validated.
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.
Integrating Gut Microbiota and Population Genomics in White Hake (Urophycis tenuis): Supporting Data
PURPOSE:The purpose of this work was to determine (1) how the population genomic structure relates to gut microbiota composition of White Hake (Urophycis tenuis), and (2) whether microbiota community variation provides complementary insights into population structure of this species in eastern Canada.DESCRIPTION:Integrating host-associated microbiota with genomic approaches offers an opportunity to better understand the multiple biological dimensions shaping population structure in marine fishes. A clear understanding of population structure and dynamics is essential for informed fisheries management and conservation decisions; however, while genomic approaches have greatly improved our ability to delineate biological populations, they provide only a partial representation of biological structure, as patterns of differentiation reflect both historical divergence and contemporary ecological conditions. Host-associated microbiota can influence population-level ecological processes by contributing functional, potentially heritable variation that shapes host phenotype and fitness.In this study, we combined genotyping-by-sequencing with 16S rRNA gene amplicon sequencing to examine how population genomic structure relates to gut microbiota composition and to evaluate whether microbiota community variation provides complementary insights into population structure in White Hake (Urophycis tenuis) in eastern Canada. Genomic analyses identified two populations with greater spatial overlap than previously reported. Variation partitioning revealed that host genetics explained a negligible proportion of microbiota variation compared to environmental factors and fish length, suggesting that ontogenetic shifts in habitat use and resource acquisition influence gut microbiota composition. Several taxa were differentially abundant among fish length categories used as a proxy for diet, including taxa with chitin-degrading potential such as Photobacterium and Lachnospirales, which were enriched in smaller fish known to consume a crustacean-dominated diet. Together, these results indicate that gut microbiota composition in White Hake primarily reflects ecological and life-history processes rather than host population structure. PARAMETERS COLLECTED:Environmental parameters were also collected at most sampling sites, including depth, water temperature, oxygen and salinity levels.PHYSICAL SAMPLE DETAILS:Fin samples were collected to characterize the fish genotypes. Intestine (rectum) samples were collected to study fish gut microbiome.SAMPLING METHODS:In 2022 and 2023, White Hake were sampled during Fisheries and Oceans Canada (DFO) annual bottom trawl ecosystem monitoring surveys.USE LIMITATION:To ensure scientific integrity and appropriate use of the data, we would encourage you to contact the data custodian.
Variation in ringed seal (Pusan hispida) density along a latitudinal gradient of sea-ice conditions
PURPOSE:Ringed seals (Pusa hispida) rely on sea ice as habitat throughout their life history and inhabit a broad latitudinal range with diverse sea-ice conditions. Anthropogenic climate warming is triggering poleward species redistributions, highlighting the importance of understanding how species distributions and abundance vary along latitudinal gradients. Using ringed seals as a model species, the purpose was to estimate density via aerial surveys along a latitudinal gradient in the eastern Canadian Arctic to investigate latitudinal trends in the ringed seals response to regional variation in sea-ice conditions. DESCRIPTION:Ringed seals (Pusa hispida) rely on sea ice as habitat throughout their life history and inhabit a broad latitudinal range with diverse sea-ice conditions, making them a model species to study patterns in density along a spatial-environmental gradient. We estimated the density of ringed seals from systematic aerial surveys along a latitudinal gradient in the eastern Canadian Arctic to investigate latitudinal trends in the ringed seals response to regional variation in sea-ice conditions. Ringed seals exhibited similar densities at lower and intermediate latitudes, while higher latitudes displayed an order of magnitude lower ringed seal density. This shift is concurrent with the transition in ice conditions from predominantly first-year ice at lower latitudes to primarily multiyear ice at higher latitudes. These findings indicate that the variation in icescapes across the ringed seal’s vast range influences their density. The shift in sea-ice conditions may also have consequences for biological productivity that supports their diet. Our results highlight a likely non-uniform response of ringed seals to ongoing sea-ice recession across the Arctic.
Grey Seal Pup Production in Canadian Waters
To estimate Grey Seal (Halichoerus grypus) pup production, photographic aerial surveys were conducted of the major Grey Seal breeding colonies in Canadian waters. The last survey was completed in January 2021. A total of 72,209 pups were counted on digital imagery from Sable Island, the largest breeding colony. Reconnaissance flights found no new colonies along the Atlantic coast of Nova Scotia and New Brunswick. Pup developmental stage surveys were undertaken on the ground or from helicopter at the seven largest breeding colonies to describe the birth distribution and correct the pup count for the estimate of pups born after the aerial photographic survey. The estimated number of pups born on Sable Island was 76,600 (SE = 2,900) and for Coastal Nova Scotia was 4,700 (SE = 550). For Sable Island, this is the first estimate of pup production since the 1960s that has not been a significant increase. Sable Island accounts for 77.5% of total pup production in Canada, and the change in trend in pup production on Sable Island is reflected in the trend in total pup production. Pup production in the Gulf of St. Lawrence continues to fluctuate with little evidence of trend over the past several decades, while at the more recently-established breeding colonies in southwest Nova Scotia, pup production continues to increase.In February 2026, the time series of grey seal pup production estimates for Maritimes Region was made open source. The open data was set up with no abbreviations or codes and restricted to just Maritimes Region. Notably there are counts in the dataset provided not linked to specific breeding colonies, for the miscellaneous locations the latitude and longitude are for roughly center of the colonies or region.Cite this data as: den Heyer., C. Data of Grey Seal Pup Production in Canadian Water. Published: April 2026. Ocean Ecosystems Science Division, Maritimes Region, Fisheries and Oceans Canada, Dartmouth NS. https://open.canada.ca/data/en/dataset/ea8962b2-0d75-4500-a3de-d631a1e5308f
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