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We have found 41 datasets for the keyword " myoxocephalus quadricornis". You can continue exploring the search results in the list below.
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41 Datasets, Page 1 of 5
Historical distribution of kelp forests on the coast of British Columbia: 1858 - 1956
This dataset is a contribution to the development of a kelp distribution vector dataset.Bull kelp (Nereocystis leutkeana) and giant kelp (Macrocystis pyrifera) are important canopy-forming kelp species found in marine nearshore habitats on the West coast of Canada. Often referred to as a foundation species, beds of kelp form structural underwater forests that offer habitat for fishes and invertebrates. Despite its far-ranging importance, kelp has experienced a decline in the west coast of North America. The losses have been in response to direct harvest, increase in herbivores through the removal of predators by fisheries or diseases, increase in water turbidity from shoreline development as well as sea temperature change, ocean acidification, and increased storm activates. Understanding these impacts and the level of resilience of different kelp populations requires spatiotemporal baselines of kelp distribution. The area covered by this dataset includes the BC coast and extends to portions of the Washington and Alaska coasts. This dataset was created using 137 British Admiralty (BA) charts, including insets, with scales ranging from 1:6,080 to 1:500,000, created between 1858 and 1956. All surveys were based on triangulation, in which a sextant or theodolite was used to determine latitude and angles, while a chronometer was used to help determine longitude.First, each BA chart was scanned by the Canadian Hydrographic Service (CHS) using the CHS Colortrac large format scanner, and saved as a Tagged Image Format at 200 DPI, which was deemed sufficient resolution to properly visualize all the features of interest. Subsequently, the scanned charts were imported into ESRI ArcMap and georeferenced directly to WGS84 using CHS georeferencing standards and principles (charts.gc.ca). In order to minimize error, a hierarchy of control points was used, ranging from high survey order control points to comparing conspicuous stable rock features apparent in satellite imagery. The georeferencing result was further validated against satellite imagery, CHS charts and fieldsheets, the CHS-Pacific High Water Line (charts.gc.ca), and adjacent and overlapping BA charts. Finally, the kelp features were digitized, and corresponding chart information (scale, chart number, title, survey start year, survey end year, and comments) was added as attributes to each feature. Given the observed differences in kelp feature representation at different scales, when digitizing kelp features, polygons were used to represent the discrete observations, and as such, they represent presence of kelp and not kelp area. Polygons were created by tracing around the kelp feature, aiming to keep the outline close to the stipe and blades.The accuracy of the location of the digitized kelp features was defined using a reliability criterion, which considers the location of the digitized kelp feature (polygon) in relation to the local depth in which the feature occurs. For this, we defined a depth threshold of 40 m to represent a low likelihood of kelp habitat in areas deeper than the threshold.An accuracy assessment of the digitized kelp features concluded that 99% of the kelp features occurred in expected areas within a depth of less than 40 m, and only about 1% of the features occurred completely outside of this depth.
Habitat Suitability of Greenland Shark (Somniosus microcephalus) in the Newfoundland and Labrador Region
Greenland Sharks (Somniosus microcephalus) are estimated to have the highest longevity of any invertebrate (392 ± 120 years), making bycatch a significant concern (Nielsen et al. 2016). However, in the Newfoundland and Labrador (NL) region, accurate estimates of bycatch are not often available for the species (Simpson et al. 2021). To address this, species distribution models (SDMs) were generated to delineate habitat suitability for the species throughout the NL region in order to identify areas where a higher rate of bycatch is expected to occur.Observations of Greenland shark bycatch recorded by At-Sea Observers (ASOs) in NL (1983 – 2019), Spain (1999 – 2017), and by the Northwest Atlantic Fisheries Organization (NAFO) Secretariat (2014 – 2019) were compiled to generate a presence-only dataset. Multiple environmental variables were assessed for collinearity, and non-collinear variables (Bathymetry and mean monthly bottom temperature for March and November (1990 – 2015)) were retained for use in the SDM. MaxEnt (maximum entropy) software was used to model habitat suitability because it is a presence-only modelling program that is able to account for a lack of absence data by comparing the environmental conditions at occurrence locations to those at randomly selected background points. Overall, the results indicated that habitat suitability for Greenland Shark was highest in deeper waters along the shelf edge in NAFO Divisions 3OP, and the Laurentian Channel, but also extended along the edge of the Labrador shelf, the Grand Banks, and deeper areas along the continental shelf such as the Hawke Channel, Funk Island Deep, and the slopes of Saglek, Nain, and Hamilton Banks. Beyond the Economic Exclusive Zone (EEZ) and within the NAFO regulatory area (NRA), suitable habitat was also present within the Flemish Pass, and along the slope of the Flemish Cap and shelf edge in NAFO Divisions 3NO (Simpson et al. 2021). More detailed information can be found in Simpson et al. 2021.References:Nielsen, J., R. B. Hedeholm, J. Heinemeier, P. G. Bushnell, J. S. Christiansen, J. Olsen, C. B. Ramsey, R. W. Brill, M. Simon, K. F. Steffensen, J. F. Steffensen. 2016. Eye lens radiocarbon reveals centuries of longevity in the Greenland shark (Somniosus microcephalus). Science 353 (6300):702-704Simpson, M. R., Gullage, L., Konecny, C., Ollerhead, N., Treble, M.A., Nogueira, A., González-Costas, F. 2021. Spatial-temporal variation in Greenland shark (Somniosus microcephalus) bycatch in the NAFO Regulatory Area. NAFO SCR Doc. 21/028
Marine mammal records collected by the At-Sea Observer program in Arctic, Newfoundland and Labrador and Maritimes regions
Records of marine mammal sightings (N = 5,324) collected by ASOs and submitted to Fisheries and Oceans Canada (DFO) between 1979-2024, across three DFO regions: the Arctic, Newfoundland and Labrador, and the Maritimes. Methods for initial data compilation are provided in the associated technical report "Marine mammal records collected by the at-sea observer (ASO) program in Arctic, Newfoundland and Labrador, and Maritimes regions: a summary of challenges and opportunities for future research." Cite this data as: Feyrer, L.J., Colbourne, N., Lawson, J.W., Moors-Murphy, H.B., Ferguson, S. Dataset update to Marine mammal records collected by the At-Sea Observer program in Arctic, Newfoundland and Labrador and Maritimes regions. Published: February 2025. Ocean Ecosystems Science Division, Fisheries and Oceans Canada, Dartmouth, N.S.
Sightings, Strandings, and Entrapment Data For Sea Turtles in Newfoundland and Labrador, Canada
The data in this dataset represent an amalgamation of sea turtle sighting, stranding, and entrapment events, mainly near Newfoundland and Labrador (NL), Canada.This document summarises the detection events data for Leatherback (Dermochelys coriacea), Loggerhead (Caretta caretta), and Green (Chelonia mydas) Turtles that has been collected from opportunistic and systematic survey sources, plus stranding and entrapment records, in the waters of NL from 1946 to 2023. To a much lesser extent there are also detection records for the southern Gulf of St. Lawrence. Scotian Shelf, and northeastern U.S. waters.These detection records are mostly derived from opportunistic reports, so there are rarely data for a report that includes measures of the observer effort expended to make the detection, and rarely associated imagery. During DFO aerial surveys there are measures of effort in most cases, enabling the turtle sightings reports to be used in habitat modelling (e.g., Mosnier et al. 2018).Most of the information variables (such as “Date”, “Latitude”, “Longitude”, “Number of Animals”) have been obtained from the detection report. In some cases data for variables such as “Location Reliability”, “ID Reliability”, “Platform”, and “Strand or Entrapment Outcome” were derived from interpretation of the comments associated with the report, if available. For description of the variables in the dataset see the Data Dictionary.References:Mosnier, A., Gosselin, J.-F., Lawson, J., Plourde, S., and Lesage, V. 2018. Predicting seasonal occurrence of leatherback turtles (Dermochelys coriacea) in eastern Canadian waters from turtle and sunfish (Mola mola) sighting data and habitat characteristics. Can. J. Zool. 97: 464-478. https://doi.org/10.1139/cjz-2018-0167
California Sea Lion Haulout Counts in British Columbia
The United States population of California Sea Lions (Zalophus californianus) range from southeast Alaska to the Pacific coast of central Mexico. While this population does not breed in Canada, some sub-adult and adult males migrate northwards to British Columbia (BC) during the non-breeding season with an arrival in August–October and a departure in April–May. The population in coastal BC was assessed in 1985 and again in 2023 from dedicated over-winter aerial surveys. The most recent assessment used counts from 2020–2021surveys that were restricted to southern BC as few animals have been documented further north. Additional observations of California Sea Lions were collected while surveying sites for Steller Sea Lions. These opportunistic counts increased from approximately 1,000 animals in the mid-2000s to several thousand individuals in more recent years. Historically occupied sea lion rookeries and haul-out sites were surveyed with nearby areas monitored for potential shifts in distribution. This dataset contains counts that have been collected from sightings of individuals from 1971 through 2021and replaces a previous dataset limited to the 2016/2017 survey season.
Forecasted Changes in Growth Potential, Egg Survival and Thermal Habitat Suitability for Cod Species in the Northwest Atlantic and Eastern Canadian Arctic
Polar cod (Boreogadus saida), Atlantic cod (Gadus morhua), and Greenland cod (Gadus macrocephalus) are prominent gadid species within the northwest Atlantic Ocean in terms of their ecological and socio-economic importance but it is unclear how climate-induced changes in ocean temperature may alter their distributions by the end of the century (2100). We used physiologically based species distribution models to predict how ocean warming will influence the availability of suitable habitat for early life-stages in these marine gadids. We applied CMIP5 ocean temperature projections to egg survival and juvenile growth models for Polar cod, Atlantic cod, and Greenland cod to create predicted suitability raster surfaces for these metrics across four climatology periods (1981–2005, 2026–2050, 2051–2075, 2076–2100). The analysis focused on the projected changes in temperature in ocean shelf areas where ocean depth is ≤400 m. We created an integrated habitat suitability index by combining the suitability surfaces for egg survival and growth potential to predict areas and periods where thermal conditions were suitable for both life stages. The resulting surfaces indicate that suitable thermal habitat for the juvenile life stages of all three species will shift poleward, but the magnitude of the shift and the overall area of thermally suitable habitat remaining will differ across species and life stages through time. Modelled layers are provided in NetCDF format by metric (egg survival, growth potential, habitat suitability). Data layers for Polar cod, Atlantic cod, and Greenland cod are included within each NetCDF file as variables across time. Note that in this study we refer to Gadus macrocephalus/ogac as Greenland cod since Gadus ogac is thought to be a junior synonym of Gadus macrocephalus (Carr et al., 1999). For more details on the methods and results for this analysis see Cote et al. (2021).References:Carr, S. M., Kivlichan, D. S., Pepin, P., & Crutcher, D. C. (1999). Molecular systematics of gadid fishes: implications for the biogeographic origins of Pacific species. Canadian Journal of Zoology, 77(1), 19–26. https://doi.org/10.1139/cjz-77-1-19Cote, D., Konecny, C. A., Seiden, J., Hauser, T., Kristiansen, T., & Laurel, B. J. (2021). Forecasted Shifts in Thermal Habitat for Cod Species in the Northwest Atlantic and Eastern Canadian Arctic. Frontiers in Marine Science, 8(November), 1–15. https://doi.org/10.3389/fmars.2021.764072
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.
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.
Scientific survey of sea scallop (Placopecten magellanicus) and Icelandic scallop (Chlamys islandica) around the Magdalen Islands (fishing area 20A)
Since 1985, research surveys targeting scallops—primarily the sea scallop (Placopecten magellanicus) and, to a lesser extent, the Icelandic scallop (Chlamys islandica)—have been conducted by Fisheries and Oceans Canada (DFO) at one- or two-year intervals around the Magdalen Islands (fishing area 20A). The main objective of this survey is to assess the status of sea scallop stocks. The study area is situated south of the Magdalen Islands, where scallop beds are typically sampled at depths ranging from approximately 25 to 35 m. Sampling stations are randomly selected from a predetermined fixed grid, with sampling conducted along transects at these randomly assigned locations within the study area. Each station is sampled using a lined Digby scallop dredge (20 mm mesh size), towed for roughly 500 m across the seabed.This publication includes three files: the file biometriePetoncle_20, which contains detailed biometric data (species, size, weights and sex) from 1998 to 2024; the file taillePetoncle_20, which provides the size of the individuals sampled from 2009 to 2024; and the file traitPetoncle_20 which contains the abundances and densities per tow from 2009 to 2024. Data on abundances and densities per tow from 1998-2008 is available upon request.This dataset is updated every one to two years as data becomes available. A cleaning of aberrant data has been carried out. However, there is missing data in various columns of the dataset – use the data with caution. If you have any questions please contact DFO.DataManagementSAISB-GestionDonneesDAISS.MPO@dfo-mpo.gc.ca or the author. For certain time periods, associated species are identified and semi-quantitatively counted directly on the sorting table, and the results are presented in the following publications: - https://open.canada.ca/data/en/dataset/6529a4b0-f863-4568-ac71-1fa26cf68679- https://open.canada.ca/data/en/dataset/71732ad5-5c70-4dbf-916d-a94e1380c53b
Operophtera brumata
Historical finds of Operophtera brumata
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