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We have found 98 datasets for the keyword " experimental gill netting". You can continue exploring the search results in the list below.
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98 Datasets, Page 1 of 10
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.
Southern Gulf of St. Lawrence (NAFO Division 4T) Atlantic Herring Experimental Gillnet Surveys
PURPOSE:To provide demographic parameters and relative indices of abundance for Atlantic herring in NAFO Division 4T.DESCRIPTION:The experimental gillnet survey is conducted in collaboration with Atlantic herring harvesters and uses standardized multi-mesh gillnets. Gillnets are set on spawning grounds in the spring and fall. Data (fish and sample) are collected to provide: (1) relative age-disaggregated indices of abundance, (2) an indicator of relative changes in fishery selectivity over time, and (3) information on the demographic composition of herring on the spawning grounds. PARAMETERS COLLECTED:Sample: sample location; sample weight; mesh size; length frequencyBiological: length; weight; gonad weight; maturity stage (biological); sex (biological); ring count (biological)USE LIMITATION:To ensure scientific integrity and appropriate use of the data, we would encourage you to contact the data custodian.
FADM - Public Sustained Yield Units
The spatial representation for a Public Sustained Yield Unit, which is an area of Crown land, usually a natural topographic unit determined by drainage areas, managed for sustained yield by the Crown through the Ministry of Forests. It includes all Crown lands within the currently established boundaries of the unit and excludes federal lands, provincial parks, experimental forest reserves, gazetted watersheds and tree farm licences. Crown land designated as a public sustained yield unit under Section 6 of the Forest Act. A portion of a TSA
Sablefish Standardized Trap Survey – Mainland Inlets
Fishing event (e.g., day, time, location, catch effort), and associated biological data from the Standardized Inlet Survey component of the annual Sablefish Research and Assessment Survey on the British Columbia coast.IntroductionDFO and the Canadian Sablefish Association undertake a collaborative fishery-independent annual research survey under a joint agreement. The survey employs longline trap gear to obtain catch rate data, gather biological samples, capture oceanographic measurements, and collect tag release and recapture data.Data summaries are provided here for standardized sets conducted at fixed stations within mainland inlets. The design of the sablefish survey has developed over time by incorporating and discontinuing components, including individual experimental studies (not available on OpenData). This Standardized Inlet Survey component differs in methodology from the other two survey components: (1) Offshore stratified random survey (2003 – present; available on OpenData using link below), and(2) Standardized trap survey – offshore indexing and offshore tagging (1990 – 2010; not yet available on OpenData). For the Standardized Inlet Survey, sets are allocated to five specific polygons in each of the following four inlet areas: Portland Inlet, Gil Island, Finlayson Channel, and Dean/Burke Channel. All four inlets were surveyed consistently between 2003 and 2019. No inlets were surveyed in 2020, and a single inlet was surveyed each year since 2021. Survey procedures are standardized and documented in Canadian Technical Reports of Fisheries and Aquatic sciences.Data tables provided for the Standardized Inlet Survey include (i) Effort, (ii) Catch, and (iii) Biological Information.Inlet EffortThis table contains information about annual survey trips and fishing events (sets). Trip-level information includes the year the survey took place, a unique trip identifier, the vessel that conducted the survey and the trip start and end dates (the dates the vessel was away from the dock conducting the survey). Set-level information includes the inlet name, date, time, location and depth that fishing took place, soak time, and number of traps deployed. All successful fishing events are included, where successful sets are those that met survey design specifications.Inlet CatchThis table contains the catch information from successful fishing events. Catch is identified to species or to the lowest taxonomic level possible. Catch is recorded as fish counts and / or weight. The unique trip identifier and set number are included so that catches can be related to the fishing event information (including capture location) for each set.Inlet Biological InformationThis table contains the biological data for sampled catches. Data may include any or all of length, weight, sex, maturity and age. Most of the sampled catch is Sablefish; however, some biological information has been collected for other species. Age structures are collected and are archived until required for analyses; therefore, all existing structures have not been aged. Tissue samples (usually a fin clip) may be collected for genetic (DNA) analysis for specific species. Tissue samples may be archived until required for analysis; for more information please see the data contacts. The unique trip identifier and set number are included so that samples can be related to the fishing event and catch information.
Sablefish Offshore Stratified Random Trap Survey
Fishing event data (e.g. year, date, time, location, catch and effort) and associated biological data from the Offshore Stratified Random Survey component of the annual Sablefish Research and Assessment Survey on the British Columbia coast.IntroductionDFO and the Canadian Sablefish Association (CSA) collaborate to undertake an annual fishery-independent research survey under a joint agreement. The survey employs longline trap gear to obtain catch rate data, gather biological samples, capture oceanographic measurements, and collect tag release and recapture data.Data summaries provided here are for the offshore stratified random sampling design (StRS) component of the survey, which has been conducted annually since 2003. The design of the sablefish survey has developed over time by incorporating and discontinuing components, including individual experimental studies (not available on OpenData). This StRS Survey component differs in methodology from the other two survey components: (1) Standardized trap survey – mainland inlets (1994-present; available on OpenData using link below), and (2) Standardized trap survey – offshore indexing and offshore tagging (1990 – 2010; not yet available on OpenData). The Sablefish offshore stratified random trap survey (StRS) follows a depth and area stratified random sampling design. The survey area is partitioned into five spatial strata (S1 to S5) and three depth strata (RD1 to RD3) for a total of 15 strata. The five spatial strata are S1 (South West Coast Vancouver Island or SWCVI), S2 (North West Coast Vancouver Island or NWCVI), S3 (Queen Charlotte Sound or QCS), S4 (South West Coast of Haida Gwaii or SWCHG), and S5 (North West Coast of Haida Gwaii or NWCHG). The three depth strata are 100-250 fathoms (RD1), 250-450 fathoms (RD2), and 450-750 fathoms (RD3). The area within each of the 15 strata are sectioned into 2 km x 2 km grid cells or ‘fishing blocks’ from which set locations are randomly chosen each year. Survey procedures are standardized and documented in Canadian Technical Reports of Fisheries and Aquatic sciences.Data tables provided for the offshore stratified random survey include (i) effort, (ii) catch, (iii) biological information, (iv) the sampling frame from which blocks are selected for sampling each year, and (v) the calculated coastwide Sablefish biomass index. StRS EffortThis table contains information about the annual survey trips and fishing events (sets). Trip-level information includes the year the survey took place, a unique trip identifier, the vessel that conducted the survey and the trip start and end dates (the dates the vessel was away from the dock conducting the survey). Set-level information includes the date, time, location and depth that fishing took place, the survey spatial and depth strata for the set, reason for the set, soak time, number of traps deployed and number of traps fished. All successful fishing events are included, i.e., those sets that conformed to specified survey standards.StRS CatchThis table contains the catch information from successful fishing events. Catches are identified to species or to the lowest taxonomic level possible. Catches are recorded as fish counts and / or weight. The unique trip identifier and set number are included so that catches can be related to the fishing event information (including capture location).StRS Biological InformationThis table contains the biological data for sampled catches. Data may include any or all of length, weight, sex, maturity, and age. Most of the sampled catch is Sablefish; however, some biological information has been collected on Rockfish, Flatfish and other Roundfish species in some years. Age structures are collected and are archived until required for analyses; therefore, all existing structures have not been aged at this time. Tissue samples (usually a fin clip) may be collected for genetic (DNA) analysis for specific species. Genetic samples may be archived until required for analyses; for more information, please see the data contacts. The unique trip identifier and set number are included so that samples can be related to the fishing event and catch information.Sample FrameThis table contains a list of all of the 2km x 2km grid cells or ‘fishing blocks’ that are part of the stratified random sampling frame. A subset of blocks are randomly selected for sampling each year from this list. For each grid cell, the corresponding depth and spatial strata ID is included. This sample frame can be used to calculate design-based abundance indices for the survey.StRS Biomass IndexThis table contains a coastwide relative biomass index for Sablefish based on the annual StRS survey. Stratified random sampling mean index values and 95% confidence intervals are calculated by year using the classical survey stratified random sampling estimator (Cochran 1977) and the number of possible sampling units per stratum provided by Wyeth et al. (2007). The relative biomass index has been input to the operating model and management procedure used to provide management advice for BC Sablefish since 2011 (Cox et al. 2011).
Canadian Land Data Assimilation System in the National Surface and River Prediction System [experimental]
CaLDAS-NSRPS was installed as an experimental system within the National Surface and River Prediction System (NSRPS) at Environment and Climate Change Canada's (ECCC) Canadian Centre for Meteorological and Environmental Prediction (CCMEP) in July 2019. CaLDAS-NSRPS is a continuous offline land-surface assimilation system, which provides analyses of the land surface every 3 h over the domain of the High-Resolution Deterministic Prediction System (HRDPS) at a 2.5 km grid spacing. The emphasis in CaLDAS-NSRPS is to focus upon the assimilation of satellite based remote sensing observations to provide the optimal initial conditions for the predictive components of the NSRPS, the High Resolution Deterministic/Ensemble Land Surface Prediction System (HRDLPS/HRELPS) and the Deterministic/Ensemble Hydrological Prediction Systems (DHPS/EHPS). CaLDAS-NSRPS is launched 4 times per day, at 0000, 0600, 1200, and 1800 UTC.
Quoddy Region Pelagics Telemetry
The project (Quoddy Region Pelagics Telemetry) will support the assessment of the effects of aquaculture on the distribution and abundance of pelagic fishes (salmon, mackerel, herring) and large predators (shark, marine mammals) in Passamaquoddy Bay and the Bay of Fundy, an area of intense finfish culture. An acoustic receivers network is placed yearly (from April to December) across various passageways, locations of project-specific interest, and at aquaculture sites in the region. Tagged pelagic species will be tracked through the network to provide information on migration routes, movement speed, survival rates and suspected predators, and determine interaction and residence at aquaculture sites. The network was utilized for monitoring the passage of: hatchery-reared wild salmon (n=340) released in the Magaguadavic River in 2018, 2019 and 2021, wild alewives (n=30) from the St. Croix River in 2021, and farmed Atlantic salmon released in the wild (n=99) in 2021. The receiver network has more recently supported adjacent projects on the use of the region by white shark and porbeagle as well as the residence of mackerel, herring, and sculpin at farm sites. The receivers additionally support other researchers with detection of striped bass, Inner Bay of Fundy Atlantic salmon, sturgeon, and many other species. Placement of the network will continue into 2025 inclusive with the longer-term goal to eventually deploy an array covering the entrance to the Bay of Fundy.Cite this data as: Trudel, M., Wilson, B., Black, M. 2023. Assessing bay-scale impacts of aquaculture operations on the distribution and abundance of pelagic fishes and large predators. Accessed via the Ocean Tracking Network OBIS IPT in January 2025 (version 3.1). https://doi.org/10.14286/xfa6sr
Fish Habitat Assessment Output from Bay of Quinte Suitability Modelling: High Water Level (75.4m ASL) - Juvenile/Adult Habitat - Low Vegetation Association Species (Coolwater Guild)
Fish Habitat Assessment Output: 7 of 16High Water Level (75.4m ASL) - Juvenile/Adult Habitat - Low Vegetation Association Species (Coolwater Guild)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.
Fish Habitat Assessment Output from Bay of Quinte Suitability Modelling: Average Water Level (75.0m ASL) - Juvenile/Adult Habitat - Low Vegetation Association Species (Coolwater Guild)
Fish Habitat Assessment Output: 15 of 16Average Water Level (75.0m ASL) - Juvenile/Adult Habitat - Low Vegetation Association Species (Coolwater Guild)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.
Fish Habitat Assessment Output from Bay of Quinte Suitability Modelling: Average Water Level (75.0m ASL) - Juvenile/Adult Habitat - Low Vegetation Association Species (Warmwater Guild)
Fish Habitat Assessment Output: 14 of 16Average Water Level (75.0m ASL) - Juvenile/Adult Habitat - Low Vegetation Association Species (Warmwater Guild)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.
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