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We have found 187 datasets for the keyword " divers". You can continue exploring the search results in the list below.
Datasets: 106,031
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187 Datasets, Page 1 of 19
Multidisciplinary winter survey for assessing groundfish in the northern Gulf of St. Lawrence (MV Gadus Atlantica 1978 - 1994)
Fisheries and Oceans Canada (DFO) conducted a winter multidisciplinary scientific surveys with a bottom trawl the northern Gulf of St. Lawrence and Cabot Straight from 1978 to 1994. The specificities of the missions onboard the MV Lady Hammond are described below.Objectives:1. Assess groundfish populations abundance and condition2. Assess environmental conditions3. Conduct a biodiversity inventory of benthic and demersal megafauna4. Collect samples for various research projectsSurvey descriptionThis winter survey covers the northern Gulf of St. Lawrence, that is the divisions 4R, 4S and 3Pn of the Northwest Atlantic Fisheries Organization (NAFO). A stratified random sampling strategy is used for this survey and the fishing gear used on the MV Gadus Atlantica is an Engel 145 Otter trawl. Standard trawling tows last 30 minutes, starting from the time the trawl touches the sea floor. Towing speed is 3.5 knots.DataFor each fishing tow, the catch is sorted and weighed by taxa; individuals are counted and biological data are collected on a subsample. For fish, crab and squid, size and weight are measured by individual and, for some species, sex, gonad maturity, and the weight of certain organs (stomach, liver, gonads) are also evaluated. The soft rays of the anal fin are counted for redfish and otoliths are collected for Greenland halibut and Atlantic cod. Invertebrates are weighted and counted (no individual measurements).The biological data are divided into 4 files: a “Metadata” file containing set information, a “Catches” file containing catches per set for fish taxa, a “Carbio” file containing morphometric measurements per individual and a “Freql” file containing the length frequency of fish. It's important to note that this is raw data. Only sets considered successful are retained. In each set, all species are kept, with a few exceptions. For more information please contact the data management team (gddaiss-dmsaisb@dfo-mpo.gc.ca).
Annual multidisciplinary survey for assessing groundfish in the northern Gulf of St. Lawrence (MV Lady Hammond 1984 - 1990)
Fisheries and Oceans Canada (DFO) conducts an annual summer multidisciplinary scientific survey with a bottom trawl in the Estuary and the northern Gulf of St. Lawrence since 1984. Over the years, this survey has been conducted on four vessels: the MV Lady Hammond (1984-1990), the CCGS Alfred Needler (1990-2005), the CCGS Teleost (2004-2021) and the CCGS Cabot (2022-current). It is important to note that the objectives, the methods used and the identification of the species during these surveys have improved over time in response to DFO requests and mandates. The data are therefore not directly comparable between these surveys. The specificities of the missions onboard the MV Lady Hammond are described below.Objectives:1. Assess groundfish populations abundance and condition2. Assess environmental conditions3. Conduct a biodiversity inventory of benthic and demersal megafauna4. Monitor the pelagic ecosystem5. Collect samples for various research projectsSurvey descriptionThe survey covers the northern Gulf of St. Lawrence, that is the divisions 4R, 4S and the northern part of division 4T of the Northwest Atlantic Fisheries Organization (NAFO). A stratified random sampling strategy is used for this survey and the fishing gear used on the MV Lady Hammond is a bottom trawl Western IIA. Standard trawling tows last 30 minutes, starting from the time the trawl touches the sea floor. Towing speed is 3.5 knots.DataFor each fishing tow, the catch is sorted and weighed by taxa; individuals are counted and biological data are collected on a sub-sample. For fish, crab and squid, size and weight are measured by individual and, for some species, sex, gonad maturity, and the weight of certain organs (stomach, liver, gonads) are also evaluated. The soft rays of the anal fin are counted for redfish and otoliths are collected for redfish and Atlantic cod. Invertebrates are weighted and counted (no individual measurements).The biological data are divided into 4 files: a “Metadata” file containing set information, a “Catches” file containing catches per set for fish taxa, a “Carbio” file containing biological and morphometric measurements per individual and a “Freql” file containing the length frequency of fish. It's important to note that this is raw data. Only sets considered successful are retained. In each set, all species are kept, with a few exceptions. For more information please contact the data management team (gddaiss-dmsaisb@dfo-mpo.gc.ca).
Taxonomic and Genetic Diversity of Decapods in Northeast Pacific, Canadian Arctic and Northwest Atlantic
An exploratory project on the taxonomic and genetic diversity of decapods in three ocean subregions (Northeast Pacific, Canadian Arctic, and Northwest Atlantic), which were sampled in 2022, was undertaken by the Arctic Working Group under the Canada-U.S. Fisheries and Climate Collaboration between Fisheries and Oceans Canada (DFO) and the National Marine Fisheries Service (NMFS) of the National Oceanic and Atmospheric Administration (NOAA). This collaboration framework aims to pool Canadian and U.S. data to explore the impacts of broad-scale climate change on marine biodiversity. In early summer 2022, a sampling protocol with the selection of targeted decapods was provided to DFO and NOAA collaborators. Targeted genera were collected from a total of 10 research programs across three ocean subregions and four marine regions. The Northeast Pacific samples were collected in the Bering Sea during the Northern Bering Sea Ecosystem and Surface Trawl Survey, and the Eastern and Northern Bering Sea Continental Shelf Bottom Trawl Survey of Groundfish and Invertebrate Fauna onboard the F/V Northwest Explorer, F/V Alaska Knight and F/V Vesteraalen. In the Western Canadian Arctic (mainly from Beaufort Sea and Amundsen Gulf), specimens were collected during DFO’s Canadian Beaufort Sea – Marine Ecosystem Assessment (CBS-MEA) survey onboard the F/V Frosti. In Eastern Canadian Arctic (mainly from Baffin Bay and Davis Strait), specimens were collected during DFO’s Knowledge and Ecosystem-Based Approach in Baffin Bay (KEBABB) survey onboard the CCGS Amundsen and DFO’s North Atlantic Fisheries Organization (NAFO) Subarea 0B survey onboard the R/V Tarajoq. In the Estuary and Gulf of St. Lawrence (EGSL), specimens were collected from coastal surveys (scallops, sea cucumber, snow crab, and whelk surveys) onboard the CCGS Leim and offshore during the Ecosystemic Survey onboard the CCGS Teleost. Decapods were collected from various sampling gears (benthic beam trawl, modified Atlantic Western IIA otter trawl, Bacalao trawl, shrimp trawl, Digby scallop dredge, or modified sea cucumber dredge) and identified to the lowest possible taxonomic level and photographed, when possible. All specimens were frozen at sea (n = 995). In the lab, the identifications were validated or refined with the photos and the frozen specimens. DNA was extracted for 87 specimens and a section of COI gene was amplified in order to be sequenced using Sanger method. Sequences were compared with existing data using The Basic Local Alignment Search Tool (BLAST) in the National Center for Bio-technology Information Nucleotide database (NCBI-nt, including the GenBank database) to compare scientific names, where available.The present dataset includes 391 decapod species occurrences. DNA was extracted for a subset of 87 specimens (COI gene); sequences are publicly available on BOLD data portal under project code DDAO (see supporting document "citations_references.csv" for more information).The data are presented in Darwin Core format and are separated in three files:The "Activité_décapodes_DDAO_decapods_event_en" file contains information about missions, stations and deployments, which are presented under a hierarchical activity structure.The "Occurrence_décapodes_DDAO_decapods_en" file contains the taxonomic occurrences.The "ADN_décapodes_DDAO_decapods_DNA_en" file contains the DNA derived data.For further details, please refer to the technical report available in the supporting document named "citations_references.csv". USE LIMITATION:To ensure scientific integrity and appropriate use of the data, we would encourage you to contact the data custodian.
Benthic Habitat Mapping Database
The purpose of the survey is to document and record habitat types and associated algae and marine invertebrate species in a variety of habitat types. Transect locations are randomly selected throughout the study area, which rotates between the north and south coasts of British Columbia on a biannual basis. Transects are laid perpendicular to the shoreline. A team of two divers swim the transect with data sheets to collect habitat, algae and marine invertebrate data as detailed below in the methods section. Data is keypunched in an MS Access database that can be queried for species observations and environmental information.This dataset includes three tables pulled from the original database containing observations by species, observations by quadrat, and additional header information for each observation. All three tables can be linked by the field HKey. Three lookup tables are included as well, one for algae, one for invertebrates, and one for substrates.
Lab and field evaluation of tagging methods for the use of acoustic telemetry to observe sea urchin movement behaviour at ecologically relevant spatio-temporal scales (https://doi.org/10.1186/s40317-022-00309-8)
Acoustic telemetry allows detailed observations of the movement behaviour of many species and as tags get smaller, smaller organisms may be tagged. The number of studies using acoustic telemetry to evaluate marine invertebrate movement is growing, but novel attachment methods include unknowns about the effects of tagging procedures on individual survival and behaviour. This study compared methods of tag attachment on green sea urchins (Strongylocentrotus droebachiensis) to determine the feasibility of using acoustic transmitters to track echinoid movement. Four tagging methods were compared in the lab and tag retention, urchin condition, and survival analysed. Two tagging methods (Dyneema® fishing line and T-bar tags) were evaluated in the field using an existing acoustic telemetry array. Urchins were tagged and the study area revisited one week and 2 months post-release by scuba divers to estimate movement and tag retention. The best methods in the lab, with high tag retention, survival, and minimal effects on urchin condition, were fishing line methods. T-bar tags, although showing high tag retention, caused significant mortality and had deleterious long-term effects on urchin condition and behaviour. After 2 months in the field, as in the lab, fishing line was a more effective tagging method. Urchins tagged with fishing line showed increased estimates of space occupancy compared to T-bar-tagged urchins and a single fishing-line tagged individual was found by divers in good health after 80 days. Combined, these laboratory and field results demonstrate the feasibility of using acoustic telemetry to observe urchin movement. Results strongly suggest that surgical attachment methods that minimize injuries at the attachment site should be prioritized for echinoid tagging studies. Together, lab and field tests indicate that acoustic telemetry is a promising method to examine marine echinoid movement over ecologically relevant spatial and temporal scales.The data available includes the laboratory data (tag retention, survival, diameter, wet weight, gonad weight and condition/righting time) and the field data (metadata and acoustic telemetry detections for tagged individuals, results of diver searches and 2-day estimates of movement measured in the field). Data from the laboratory experiment and diver observations in the field have been verified and undergone a control for quality. Acoustic telemetry detections are raw detection files (unfiltered); see the published article for a description of how the data were treated for analyses (https://doi.org/10.1186/s40317-022-00309-8).
Provincial Sanctuary - Corridor Wildlife
The Provincial Sanctuary - Corridor Wildlife dataset is comprised of all the polygons that represent the Provincial Sanctuary - Corridor Wildlife areas in Alberta. Provincial Sanctuary - Corridor Wildlife is area designated for the protection of wildlife within 400 yards corridors of various road centre-lines.
Multispecies Dive Pilot Surveys
The Department of Fisheries and Oceans (DFO) Science Branch has designed a multispecies dive survey protocol to provide unbiased, coast wide monitoring of benthic invertebrate stocks (as may be required under the updated Fisheries Act) and associated habitat information for a suite of benthic marine invertebrate species (Green (Strongylocentrotus droebachiensis), Purple (S. purpuratus) and Red Sea Urchin (Mesocentrotus franciscanus), Geoduck (Panopea generosa), Giant Red Sea Cucumber (Apostichopus californicus), Northern Abalone (Haliotis kamtschatkana), and Sunflower Sea Star (Pycnopodia helianthoides)). Based on information available at this time, the proposed survey design can provide estimates of coast wide stock status for Red Sea Urchin and Giant Red Sea Cucumber, and relative abundance indices for Geoduck, Green Sea Urchin, Purple Sea Urchin, Northern Abalone and Sunflower Sea Star.The new protocol was tested through a series of pilot surveys conducted on a subset of areas of the BC coast each September from 2016-2021. Design of the pilot surveys was based on previous dive survey data and experience and demonstrated the practical feasibility of the protocol, while also gathering preliminary information to guide recommendations about the statistical design of the survey.The dataset consists of a relational database containing tables representing each component of the survey methodology. The primary component of the survey is a transect location. Along each transect, systematically spaced quadrats are sampled, and on each quadrat, substrate observations are recorded, multiple species of algae are recorded, and multiple individual invertebrates are measured or counted. The tables are linked by transect number and quadrat number.
SCUBA-Based Assessment of Lobster Density and Structure in the Southern Gulf
PURPOSE:The SCUBA survey was designed to assess the density of small lobsters (1-3 years of age) in rocky reefs, in the nearshore habitat.DESCRIPTION:Total number of transects surveyed and total number of lobsters measured for each site in each year. There are some sites that do not have any coordinates identified, therefore these have not been included in the Web Map Services (WMS). PARAMETERS COLLECTED:Size measurement (biological); species counts (ecological); substrate (geological)SAMPLING METHODS:Transects are laid out from a small vessel using buoys, anchors, and a 100 m leaded rope along the bottom, marked at 5 m intervals. A strip transect survey method is used whereas two divers sample a 1 or 2 m strip (dependent on lobster density) alongside either side of the leaded rope. All captured lobsters are measured (carapace length) and all lobsters of ≥20 mm carapace length are sexed. The complexity and suitability of the habitat is assessed in the 5 m sections (e.g. rocky reefs, sand, large boulders).USE LIMITATION:To ensure scientific integrity and appropriate use of the data, we would encourage you to contact the data custodian.
Sponge occurrence and associated species and habitat descriptions derived from the 2021 and 2022 SCUBA diving surveys in the Eastern Shore Islands Area of Interest, Nova Scotia
Funded under DFO's Marine Conservation Targets Program in partnership with the Huntsman Marine Science Centre (HMSC), this diver-based imagery and sample collection benthic survey documents the occurrence of sponges at 42 dive sites in the Eastern Shore Islands (ESI) Area of Interest (AOI, ~2089 km2) off the Atlantic coast of Nova Scotia, Canada from dive surveys conducted in summer 2021 and 2022. Water quality, species occurrences and counts, habitat, slope, and substrate characteristics were catalogued through diver log sheets, camera imagery, specimen vouchers, and high-resolution bathymetric data. A total of 54 dives to depths from 11 to 33 m (below sea level), collecting up to 147 still images, one-hour of video, and 17 specimen samples per site, resulted in 220 observations for 27 different sponge taxa. This included three new records for Canada (Hymedesmia stellifera, Plocamionida arndti, Hymedesmia jecusculum) and a range extension for a species new to science (Crellomima mehqisinpekonuta) which was recently described from the Bay of Fundy. There were also four species which may seem to be new to science (Halichondria sp., Hymedesmia sp., Protosuberires sp., and Sphaerotylus sp.). Sponges were found to occupy a diversity of micro-habitats, often several different ones in proximity. A total of eight distinct habitat classes were defined, based on varying abundances and diversity of sponges and associated benthic species. These are likely widely distributed among the many complex submerged seabed features within this AOI. Collected specimens were preserved and are stored at the Atlantic Reference Centre (ARC) in St. Andrew's, New Brunswick.Cite this data as: Goodwin, C., Cooper, J.A., Lawton, P., Teed, L.L. 2025. Sponge occurrence and associated species and habitat descriptions derived from the 2021 and 2022 SCUBA diving surveys in the Eastern Shore Islands Area of Interest, Nova Scotia. Version 1.4. Fisheries and Oceans Canada. Occurrence dataset. https://ipt.iobis.org/obiscanada/resource?r=eastern_shore_islands_sponge_survey_2021_2022&v=1.4
Demersal fish and benthic invertebrate assemblages in the Northwest Atlantic
Marine classification schemes based on abiotic surrogates often inform regional marine conservation planning in lieu of detailed biological data. However, theses chemes may poorly represent ecologically relevant biological patterns required for effective design and management strategies. We used a community-level modeling approach to characterize and delineate representative mesoscale (tens to thousands of kilometers) assemblages of demersal fish and benthic invertebrates in the North-west Atlantic. Hierarchical clustering of species occurrence data from four regional annual multispecies trawl surveys revealed three to six groupings (predominant assemblage types) in each survey region, broadly associated with geomorphic and oceanographic features. Indicator analyses identified 3–34 emblematic taxa of each assemblage type. Random forest classifications accurately predicted assemblage dis-tributions from environmental covariates (AUC > 0.95) and identified thermal limits (annual minimum and maximum bottom temperatures) as important pre-dictors of distribution in each region. Using forecasted oceanographic conditions for the year 2075 and a regional classification model, we projected assemblage dis-tributions in the southernmost bioregion (Scotian Shelf-Bay of Fundy) under ahigh emissions climate scenario (RCP 8.5). Range expansions to the north eastare projected for assemblages associated with warmer and shallower waters of the Western Scotian Shelf over the 21st century as thermal habitat on the rela-tively cooler Eastern Scotian Shelf becomes more favorable. Community-level modeling provides a biotic-informed approach for identifying broadscale ecolog-ical structure required for the design and management of ecologically coherent, representative, well-connected networks of Marine Protected Areas. When com-bined with oceanographic forecasts, this modeling approach provides a spatial tool for assessing sensitivity and resilience to climate change, which can improve conservation planning, monitoring, and adaptive management.Cite this data as: O'Brien, J.M., Stanley, R.R.E., Jeffery, N.W., Heaslip, S.W., DiBacco, C., and Wang, Z. Demersal fish and benthic invertebrate assemblages in the Northwest Atlantic.Published: December 2024. Coastal Ecosystems Science Division, Maritimes region, Fisheries and Oceans Canada, Dartmouth NS.https://open.canada.ca/data/en/dataset/14d55ea5-b17d-478c-b9ee-6a7c04439d2b
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