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We have found 42 datasets for the keyword " gulls". You can continue exploring the search results in the list below.
Datasets: 106,578
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42 Datasets, Page 1 of 5
Wild Bird Health and Contaminants, Oil Sands Region
Aquatic bird eggs are being collected for contaminants analysis. Egg collections in the Peace-Athabasca Delta area support Parks Canada’s activities at Wood Buffalo National Park and the multi-stakeholder Peace-Athabasca Ecosystem Monitoring Program. This monitoring activity employs repeated censuses of birds and builds on initial egg collections made in 2009 from Egg Island (Lake Athabasca) and Wood Buffalo National Park, with the goal of evaluating contaminant burdens, contaminant sources and changes in sources through time. Egg samples are collected from colonial waterbirds California Gulls (Larus californicus), Herring Gulls (Larus argentatus), Ring-billed Gulls (Larus delawarensis), Caspian Terns (Hydroprogne caspia) and Common Terns (Sterna hirundo) and insectivorous birds Bank Swallows (Riparia riparia), Cliff Swallows (Petrochelidon pyrrhonota) and Tree Swallows (Tachycineta bicolor) to monitor health and contaminant levels of aquatic and terrestrial birds in the oil sands region and in reference areas. The samples collected are analysed for oil sands-related contaminants including polycyclic aromatic hydrocarbons (PAHs) and metals such as mercury (Hg) and arsenic (As).
Mackenzie River Exploratory Fishery 1989-1993; Investigation of the Population Structure of Broad Whitefish (Coregonus nasus) and Biological Analysis and Population Assessment of Northern Pike (Esox lucius), Inconnu (Stenodus leucichthys), and Lake Whitefish (Coregonus clupeaformis)
An exploratory fishery was carried out in the Mackenzie River Delta between 1989 and 1993 at the request of the Inuvik Hunters and Trappers Committee to assess the commercial fishery potential in this area. Data collected during this exploratory fishery was used in two technical reports. Broad whitefish were the target species of this fishery (DFO Technical Report 2180), however other species such as northern pike, inconnu, and lake whitefish were also harvested (DFO Technical Report 2330).Biological data from broad whitefish (fork length, age, gonadosomatic index and instantaneous mortality) were analyzed to assess the impact of an exploratory fishery in the Mackenzie River Delta. The data were collected using variable mesh experimental gill nets and commercial harvesters' 139 mm (5.5”) mesh gill nets. The data suggest that the broad whitefish population might be separated, with larger mature spawners gathering in the main channels prior to spawning and smaller, immature or resting fish staying in side channels away from strong currents. From this analysis we conclude that the size and structure of the broad whitefish population(s) found in this area are stable at the current level of total harvest (commercial and subsistence combined) There may be room for increased harvests but to what level is uncertain.Biological data from northern pike, inconnu, and lake whitefish were analyzed to assess the impact of the fishery on population abundance and structure. All three by catch species support subsistence fisheries in the Mackenzie Delta. lnconnu and lake whitefish migrate substantial distances, crossing land claim borders and are likely fished by a variety of user groups. Northern pike, on the other hand tend to be non-migratory with localized populations that are mainly fished by people living in the near vicinity. A concern was that commercial fishing pressure might reduce the numbers of fish available to subsistence users. Based on trends in size and age frequency, age at maturity, sex ratio, growth rates, and mortality rates, we conclude that inconnu and lake whitefish populations in the Mackenzie Delta have remained healthy and stable at the current harvest levels, however northern pike populations showed a decrease in the proportion of older fish, possibly indicating over-fishing of local stocks. lnconnu and lake whitefish may be able to withstand increased harvest, but to what extent is unknown, given that little reliable information is available on subsistence harvest levels in this region. Increasing harvest levels of pike may be risky and we suggest that a reduction of current commercial harvest quotas be considered.
Recovered Historic Catch and Weight – Length Data of Nearshore Fish Populations on Sturgeon and Roberts Banks, Fraser River Estuary, British Columbia
A goal of the Government of Canada’s Coastal Environmental Baseline Program (CEBP) is to amalgamate historic environmental data from high vessel traffic areas. An extensive DFO biological sampling program was conducted from 1980 to 1981 on Sturgeon and Roberts banks located on the outer Fraser River estuary, BC, Canada. This report collates and simplifies three data sets: water quality and nearshore fish catch previously published as DFO Data Report 340 (Conlin et al.1982), and un- published weight-length (W-L) data for two locations on Sturgeon Bank (Iona and Steveston) and near Westshore Terminals (Coal Port) on Roberts Bank. W-L data were reconstructed from archived computer printouts using Optical Character Recognition methods. Analyses of water quality data indicate that the two banks provided different fish habitats with Sturgeon Bank having a greater freshwater influence. Although Iona area water quality was exposed to sewage outfall from a nearby sewage treatment plant, it appears that fish communities were not different from the other Sturgeon Bank area (Steveston). The fish communities were found to be different between the two banks with Roberts Bank having greater overall abundance and diversity. Interestingly, of the seven fish species used for condition factor analyses, five were found to have lower Relative Condition Factors in the Roberts Bank sampling area.
Loons and Grebes - Coastal Resource Information Management System (CRIMS)
Distribution of loon and grebe bird species habitat in coastal British Columbia showing relative abundance (RA) by season and overall relative importance (RI). RI is based on project region and not on the province as a whole. 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.
Fish Habitat Assessment Output from Bay of Quinte Suitability Modelling: High Water Level (75.4m ASL) - Spawning Habitat - High Vegetation Association Species (All Temperature Windows)
Fish Habitat Assessment Output: 1 of 16High Water Level (75.4m ASL) - Spawning Habitat - High Vegetation Association Species (All Temperature Windows)Habitat suitability was assessed for the Bay of Quinte Area of Concern, at a 3 m grid resolution, using the Habitat Ecosystem Assessment Tool (HEAT), temperature algorithms, vegetation models, and water level input. Habitat classifications were based on three variables: depth (elevation), vegetation, and substrate; and modified by temperature suitabilities. The final suitability maps were based on documented habitat and temperature associations for the fish in the area. Different life stages (spawning requirements, nursery habitat, adult habitat) were modeled for the years of 1972-2011. Suitability values were scaled from 0 (not suitable) to 1 (highly suitable) and converted to suitability classes of very low, low, medium, and high. The final maps for each guild – life stage combination are maximum suitability values from the 39-year period modelled.
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
Crop (corn) heat units
Crop Heat Units (CHU) are calculated on a daily basis, using the maximum and minimum temperatures in order to account for a crop’s negative response to higher temperatures.The formula used to calculate the CHU value for a day is: (1.8 × (Minimum Temperature − 4.4) + 3.33 × (Maximum Temperature − 10) − 0.084 × (Maximum Temperature − 10)²) ÷ 2.0CHU values are only accumulated during the Growing Season, April 1 through October 31.
Bay Scale Assessment of Eelgrass Using Sidescan and Video - Cocagne 2008
The assessment of the status of eelgrass (Zostera marina) beds at the bay-scale in turbid, shallow estuaries is problematic. The bay-scale assessment (i.e., tens of km) of eelgrass beds usually involves remote sensing methods such as aerial photography or satellite imagery. These methods can fail if the water column is turbid, as is the case for many shallow estuaries on Canada’s eastern seaboard. A novel towfish package was developed for the bay-scale assessment of eelgrass beds irrespective of water column turbidity. The towfish consisted of an underwater video camera with scaling lasers, sidescan sonar and a transponder-based positioning system. The towfish was deployed along predetermined transects in three northern New Brunswick estuaries. Maps were created of eelgrass cover and health (epiphyte load) and ancillary bottom features such as benthic algal growth, bacterial mats (Beggiatoa) and oysters. All three estuaries had accumulations of material reminiscent of the oomycete Leptomitus, although it was not positively identified in our study. Tabusintac held the most extensive eelgrass beds of the best health. Cocagne had the lowest scores for eelgrass health, while Bouctouche was slightly better. The towfish method proved to be cost effective and useful for the bay-scale assessment of eelgrass beds to sub-meter precision in real time.Cite this data as: Vandermeulen H. Data of: Bay Scale Assessment of Eelgrass Using Sidescan and Video - Cocagne 2008. Published: November 2019. Coastal Ecosystems Science Division, Fisheries and Oceans Canada, Dartmouth, N.S. https://open.canada.ca/data/en/dataset/431c815e-65f0-477b-9389-060fa41ec955
Range Units
A Range Unit is an administrative area established to assist in the management of the range program. Typically made up of one or more pastures. Generally, one or more Range Units make up a Stock Range
Bay Scale Assessment of Eelgrass Beds Using Sidescan and Video - Richibucto 2007
A towfish containing sidescan and video hardware was used to map eelgrass in two shallow northern New Brunswick estuaries. The sidescan and video data were useful in documenting suspected impacts of oyster aquaculture gear and eutrophication on eelgrass. With one boat and a crew of three, the mapping was accomplished at a rate of almost 10 km2 per day. That rate far exceeds what could be accomplished by a SCUBA based survey with the same crew. Moreover, the towfish survey applied with a complementary echosounder survey is potentially a more cost effective mapping method than satellite based remote sensing.Cite this data as: Vandermeulen H. Data of: Bay Scale Assessment of Eelgrass Beds Using Sidescan and Video - Richibucto 2007. Published: October 2017. Coastal Ecosystems Science Division, Fisheries and Oceans Canada, Dartmouth, N.S. https://open.canada.ca/data/en/dataset/ca7af8ba-8810-4de5-aa91-473613b0b38d
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