Bottom Trawl
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Catch, effort, location (latitude and longitude), and associated biological data from the Eulachon Migration Study Bottom Trawl surveys on the coast of British Columbia. Introduction: The Eulachon Migration Study Bottom Trawl surveys are divided into two parts; the Eulachon Migration Study Bottom Trawl – South (Eul –S) and the Eulachon Migration Study Bottom Trawl – North (Eul-N). The objectives of these surveys were to learn about the distribution, ecology, and migration timing of Eulachon into and out of the Fraser (Eul-S), Nass, and Skeena River (Eul-N) systems. This was achieved by observing Eulachon spatial and temporal occurrence and biological condition over a wide survey region each month. EUL-S covered portions of the Strait of Georgia and Juan de Fuca Strait in Pacific Fishery Management areas (PFMA’s) 17-20, 28, 29, and 121. There were nine trips conducted from October 2017 to March 2018 and one trip in January 2019. Eul-N consists of seven trips conducted between July 2018 and March 2019 mainly in Chatham Sound with sets in Hecate Strait, and Portland Inlet (Pacific Fishery Management areas (PFMA’s) 3, 4, and 104). Fishing was conducted using the Canadian Coast Guard Research Vessel Neocaligus to tow an American shrimp trawl net (Cantrawl Nets Ltd., Richmond, BC). The horizontal opening of the polypropylene net was estimated to be 34 to 37 feet (10 to 11 m), while the center of the opening had a vertical height of approximately 7 to 9 feet (2 to 3 m). A 0.4” (10 mm) liner was used in the codend. The net was configured with roller gear and 72” (1.8 m) Thyboron Type 2 trawl doors. Tow duration was typically 20 minutes for Eul-S and ranged from 5-20 minutes for Eul-N. The standard hours of fishing were 0700 to 1700 hours, depending on sunrise and sunset in winter months. These surveys follow a random block design in a targeted depth range of 80 – 200 metres for the Eul-S and 80-300 metres for Eul-N. The surveys were conducted by the Department of Fisheries and Oceans Canada (DFO) and was funded by the Fisheries and Oceans Canada (DFO) National Rotational Survey Fund.
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Catch, effort, location (latitude and longitude), and associated biological data from the Eulachon Migration Study Bottom Trawl surveys - North on the coast of British Columbia. Introduction: The Eulachon Migration Study Bottom Trawl survey - North (Eul-N) is part of the in the Eulachon Migration Study Bottom Trawl survey series and took place on the coast of British Columbia. The other survey in this series is the Eulachon Migration Study Bottom Trawl survey –South (Eul-S). The Eulachon Migration Study Bottom Trawl survey - North (Eul-N) was conducted monthly from July 2018 to March 2019 and was funded by the Fisheries and Oceans Canada (DFO) National Rotational Survey Fund. The objective of this survey was to learn about the distribution, ecology, and migration times of Eulachon into the Nass and Skeena rivers by observing their spatial and temporal occurrence and biological condition over a wide survey region and over several months. This survey follows a random block design in a targeted depth range of 80 – 300 metres. The sampling units were 2 km by 2 km blocks. Fishing was conducted using the Canadian Coast Guard Research Vessel Neocaligus to tow an American shrimp trawl net (Cantrawl Nets Ltd., Richmond, BC). The horizontal opening of the polypropylene net was estimated to be 34 to 37 feet (10 to 11 m), while the center of the opening had a vertical height of approximately 7 to 9 feet (2 to 3 m). A 0.4” (10 mm) liner was used in the codend. The net was configured with roller gear and 72” (1.8 m) Thyboron Type 2 trawl doors. Tow duration was typically 5 minutes. The standard hours of fishing were 0800 to 1700 hours, depending on sunrise and sunset in winter months. The Eulachon Migration Study Bottom Trawl survey – North was conducted by the Department of Fisheries and Oceans Canada (DFO). This survey fished mainly in Chatham Sound with sets in Hecate Strait and Portland Inlet including Pacific Fishery Management areas (PFMA’s) 3, 4, and 104. Effort: This table contains information about the survey trips and fishing events (trawl tows/sets) that are part of this survey series. 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, as well as information that can be used to calculate fishing effort (duration) and swept area. All successful fishing events are included, regardless of what was caught. Catch: This table contains the catch information from successful fishing events. Catches are identified to species or to the lowest taxonomic level possible. Most catches are weighed, but some are too small (“trace” amounts) or too large (e.g. very large Big Skate). The unique trip identifier and set number are included so that catches can be related to the fishing event information (including capture location). Biology: This table contains Eulachon biological data including length, sex, and weight. Information is provided on whether stomachs or teeth were examined, and whether genetics (DNA) samples were collected. Eulachon maturity data, diet data, and teeth presence data are available on request from the data contacts. Additional analyses are ongoing, including histology, fatty acid profiling, and genetic analysis; frozen heads are also available for a future aging project. In addition to the Eulachon biological data, lengths and weights were collected from American Shad.The unique trip identifier and set number are included so that samples can be related to the fishing event and catch information.
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Catch, effort, location (latitude and longitude), and associated biological data from the Eulachon Migration Study Bottom Trawl surveys - South on the coast of British Columbia. Introduction: The Eulachon Migration Study Bottom Trawl survey - South (Eul-S) is part of the in the Eulachon Migration Study Bottom Trawl survey series and took place on the coast of British Columbia. The other survey in this series is the Eulachon Migration Study Bottom Trawl survey – North (Eul-N). The Eulachon Migration Study Bottom Trawl survey - South (Eul-S) was conducted monthly from October 2017 to March 2018 with an additional trip in January 2019 and was funded by the Fisheries and Oceans Canada (DFO) National Rotational Survey Fund. The objective of this survey was learn about the distribution, ecology, and migration times of Eulachon into the Fraser River by observing their spatial and temporal occurrence and biological condition over a wide survey region and over several months. This survey follows a random block design in a targeted depth range between 80 – 200 metres. The sampling units are 2 km by 2 km blocks. Fishing was conducted using the Canadian Coast Guard Research Vessel Neocaligus to tow an American shrimp trawl net (Cantrawl Nets Ltd., Richmond, BC). The horizontal opening of the polypropylene net was estimated to be 34 to 37 feet (10 to 11 m), while the center of the opening had a vertical height of approximately 7 to 9 feet (2 to 3 m). A 0.4” (10 mm) liner was used in the codend. The net was configured with roller gear and 72” (1.8 m) Thyboron Type 2 trawl doors. Tow duration was typically 20 minutes. The standard hours of fishing were 0700 to 1700 hours, depending on sunrise and sunset in winter months. The Eulachon Migration Study Bottom Trawl survey – South was conducted by the Department of Fisheries and Oceans Canada (DFO). The area the survey covered included the Strait of Georgia, Juan de Fuca Strait, and Haro Strait in Pacific Fishery Management areas (PFMA’s) 17-20, 28, 29, and 121. Effort: This table contains information about the survey trips and fishing events (trawl tows/sets) that are part of this survey series. 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, as well as information that can be used to calculate fishing effort (duration) and swept area. All successful fishing events are included, regardless of what was caught. Catch: This table contains the catch information from successful fishing events. Catches are identified to species or to the lowest taxonomic level possible. Most catches are weighed, but some are too small (“trace” amounts) or too large (e.g. very large Big Skate). The unique trip identifier and set number are included so that catches can be related to the fishing event information (including capture location). Biology: This table contains Eulachon biological data including length, sex, and weight. Information is provided on whether stomachs or teeth were examined, and whether genetics (DNA) samples were collected. Eulachon maturity data, diet data, and teeth presence data are available on request from the data contacts. Additional analyses are ongoing, including histology, fatty acid profiling, and genetic analysis; frozen heads are also available for a future aging project. In addition to the Eulachon biological data, lengths and weights were collected from American Shad. The unique trip identifier and set number are included so that samples can be related to the fishing event and catch information.
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Catch, effort, location (latitude and longitude), and associated biological data from the Hecate Strait Multispecies Assemblage Bottom Trawl Surveys in Hecate Strait, British Columbia. Introduction The Hecate Strait Multispecies Assemblage Bottom Trawl survey series consists of twelve surveys that were conducted from 1984 to 2003 by the Pacific Biological Station, Fisheries and Oceans Canada. The main objective of this survey series was to collect detailed catch and biological data on species assemblages in order to develop an ecological basis for mixed species stock assessment in Hecate Strait. These surveys also provided abundance indices for individual species and were a source of information on recruitment. The surveys were conducted using a combination of charter vessels and two Canadian Coast Guard Research Vessels, the R/V G.B. Reed and R/V W.E. Ricker. To determine haul locations, a grid of 19 km² (10 nautical miles²) blocks were used with an attempt made to establish one trawl site within each 18 metre depth interval within each block. The 1984 survey involved one chartered and one research vessel; all other surveys were single vessel surveys. The Hecate Strait Multispecies Assemblage Bottom Trawl survey series surveyed Pacific Fishery Management areas 4, 5, and 101 to 106. A total of 1,111 number of tows were made with a Yankee 36 trawl net. This survey series is the predecessor for the present day Hecate Strait Synoptic Bottom Trawl Survey and represents one of the longest running time series of fisheries independent groundfish surveys on the west coast. For further details about the Hecate Strait Multispecies assemblage bottom trawl survey series, a list of reports can be found in the supporting documents section. Effort This table contains information about the survey trips and fishing events (trawl tows/sets) that are part of this survey series. 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, as well as information that can be used to calculate fishing effort (duration) and swept area. All successful fishing events are included, regardless of what was caught. Catch This table contains the catch information from successful fishing events. Catches are identified to species or to the lowest taxonomic level possible. Most catches are weighed, but some are too small (“trace” amounts) or too large (e.g. very large Big Skate). The unique trip identifier and set number are included so that catches can be related to the fishing event information (including capture location). Biology This table contains the available biological data for catches which were sampled. Data may include any or all of length, sex, weight, age. Different length types are measured depending on the species. Age structures are collected when possible for species where validated aging methods exist and are archived until required for an assessment; therefore, all existing structures have not been aged at this time. The unique trip identifier and set number are included so that samples can be related to the fishing event and catch information. Biomass This table contains relative biomass indices of species that have been captured in every survey of the time series. The coefficient of variation and bootstrapped 95% confidence intervals are provided for each index. The groundfish data synopsis report (Anderson et al. 2019) provides an explanation of how the relative biomass indices are derived.
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Catch, effort, location (latitude, longitude), relative abundance indices, and associated biological data from groundfish multi-species bottom trawl surveys in Queen Charlotte Sound. Introduction The Queen Charlotte Sound (QCS) synoptic bottom trawl survey was conducted annually from 2003 to 2005 and has since been repeated every second year on the odd-numbered years. The survey was not impacted by the COVID-19 pandemic. This survey is one of a set of long-term and coordinated surveys that together cover the continental shelf and upper slope of most of the British Columbia coast. The other surveys are the Hecate Strait (HS) survey, the West Coast Vancouver Island (WCVI) survey, the West Coast Haida Gwaii (WCHG) survey, and the Strait of Georgia (SOG) survey. The objectives of these surveys are to provide fishery independent abundance indices of all demersal fish species available to bottom trawling and to collect biological samples of selected species. The surveys follow a random depth-stratified design and the sampling units are 2 km by 2 km blocks. The synoptic bottom trawl surveys are conducted by Fisheries and Oceans Canada (DFO) in collaboration with the Canadian Groundfish Research and Conservation Society (CGRCS), a non-profit society composed of participants in the British Columbia commercial groundfish trawl fishery. The Queen Charlotte Sound and West Coast Haida Gwaii surveys are conducted under collaborative agreements, with the CGRCS providing chartered commercial fishing vessels and field technicians, while DFO provides in-kind contributions for running the surveys including personnel and equipment. The Hecate Strait, West Coast Vancouver Island, and Strait of Georgia surveys are conducted by DFO and have typically taken place on a Canadian Coast Guard research vessel. Until 2016 this vessel was the CCGS W.E. Ricker. From 2021 onwards, this vessel was the CCGS Sir John Franklin. In years when a coast guard vessel has not been available, the Hecate Strait, West Coast Vancouver Island, and Strait of Georgia surveys have taken place on chartered industry vessels. Data from these surveys are also presented in the groundfish data synopsis report (Anderson et al. 2019). Effort This table contains information about the survey trips and fishing events (trawl tows/sets) that are part of this survey series. 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, as well as information that can be used to calculate fishing effort (duration) and swept area. All successful fishing events are included, regardless of what was caught. Catch This table contains the catch information from successful fishing events. Catches are identified to species or to the lowest taxonomic level possible. Most catches are weighed, but some are too small (“trace” amounts) or too large (e.g. very large Big Skate). The unique trip identifier and set number are included so that catches can be related to the fishing event information (including capture location). Biology This table contains the available biological data for catches which were sampled. Data may include any or all of length, sex, weight, age. Different length types are measured depending on the species. Age structures are collected when possible for species where validated aging methods exist and are archived until required for an assessment; therefore, all existing structures have not been aged at this time. The unique trip identifier and set number are included so that samples can be related to the fishing event and catch information. Biomass This table contains relative biomass indices of species that have been captured in every survey of the time series. The coefficient of variation and bootstrapped 95% confidence intervals are provided for each index. The groundfish data synopsis report (Anderson et al. 2019) provides an explanation of how the relative biomass indices are derived.
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Catch, effort, location (latitude, longitude), relative abundance indices, and associated biological data from groundfish multi-species bottom trawl surveys in Queen Charlotte Sound (QCS), Hecate Strait (HS), West Coast Vancouver Island (WCVI), West Coast Haida Gwaii (WCHG) and the Strait of Georgia (SOG), British Columbia. Introduction This is a set of long-term and coordinated surveys that together cover the continental shelf and upper slope of most of the British Columbia coast. The objectives of these surveys are to provide fishery-independent abundance indices of all demersal fish species available to bottom trawling and to collect biological samples of selected species. The surveys follow a random depth-stratified design and the sampling units are 2 km by 2 km blocks. The synoptic bottom trawl surveys are conducted by Fisheries and Oceans Canada (DFO) in collaboration with the Canadian Groundfish Research and Conservation Society (CGRCS), a non-profit society composed of participants in the British Columbia commercial groundfish trawl fishery. The Queen Charlotte Sound and West Coast Haida Gwaii surveys are conducted under collaborative agreements, with the CGRCS providing chartered commercial fishing vessels and field technicians, while DFO provides in-kind contributions for running the surveys including personnel and equipment. The Hecate Strait, West Coast Vancouver Island, and Strait of Georgia surveys are conducted by DFO and have typically taken place on the Canadian Coast Guard research vessel W.E. Ricker. In years when the W.E. Ricker has not been available, the Hecate Strait and West Coast Vancouver Island surveys have taken place on chartered industry vessels.
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Catch, effort, location (latitude, longitude), relative abundance indices, and associated biological data from groundfish multi-species bottom trawl surveys in Hecate Strait. Introduction The Hecate Strait (HS) synoptic bottom trawl survey was first conducted in 2005, and has been repeated every second year since. The survey was not impacted by the COVID-19 pandemic. This survey is one of a set of long-term and coordinated surveys that together cover the continental shelf and upper slope of most of the British Columbia coast. The other surveys are the Queen Charlotte Sound (QCS) survey, the West Coast Vancouver Island (WCVI) survey, the West Coast Haida Gwaii (WCHG) survey, and the Strait of Georgia (SOG) survey. The objectives of these surveys are to provide fishery-independent abundance indices of all demersal fish species available to bottom trawling and to collect biological samples of selected species. The surveys follow a random depth-stratified design and the sampling units are 2 km by 2 km blocks. The synoptic bottom trawl surveys are conducted by Fisheries and Oceans Canada (DFO) in collaboration with the Canadian Groundfish Research and Conservation Society (CGRCS), a non-profit society composed of participants in the British Columbia commercial groundfish trawl fishery. The Queen Charlotte Sound and West Coast Haida Gwaii surveys are conducted under collaborative agreements, with the CGRCS providing chartered commercial fishing vessels and field technicians, while DFO provides in-kind contributions for running the surveys including personnel and equipment. The Hecate Strait, West Coast Vancouver Island, and Strait of Georgia surveys are conducted by DFO and have typically taken place on a Canadian Coast Guard research vessel. Until 2016 this vessel was the CCGS W.E. Ricker. From 2021 onwards, this vessel was the CCGS Sir John Franklin. In years when a coast guard vessel has not been available, the Hecate Strait, West Coast Vancouver Island, and Strait of Georgia surveys have taken place on chartered industry vessels. Data from these surveys are also presented in the groundfish data synopsis report (Anderson et al. 2019). Effort This table contains information about the survey trips and fishing events (trawl tows/sets) that are part of this survey series. 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, as well as information that can be used to calculate fishing effort (duration) and swept area. All successful fishing events are included, regardless of what was caught. Catch This table contains the catch information from successful fishing events. Catches are identified to species or to the lowest taxonomic level possible. Most catches are weighed, but some are too small (“trace” amounts) or too large (e.g. very large Big Skate). The unique trip identifier and set number are included so that catches can be related to the fishing event information (including capture location). Biology This table contains the available biological data for catches which were sampled. Data may include any or all of length, sex, weight, age. Different length types are measured depending on the species. Age structures are collected when possible for species where validated aging methods exist and are archived until required for an assessment; therefore, all existing structures have not been aged at this time. The unique trip identifier and set number are included so that samples can be related to the fishing event and catch information. Biomass This table contains relative biomass indices of species that have been captured in every survey of the time series. The coefficient of variation and bootstrapped 95% confidence intervals are provided for each index. The groundfish data synopsis report (Anderson et al. 2019) provides an explanation of how the relative biomass indices are derived.
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Catch, effort, location (latitude, longitude), relative abundance indices, and associated biological data from groundfish multi-species bottom trawl surveys in West Coast Haida Gwaii. Introduction The West Coast Haida Gwaii (WCHG) synoptic bottom trawl survey was first conducted annually from 2006 to 2008 and has since been repeated every second year on even numbered years. The survey was not impacted by the COVID-19 pandemic. This survey is one of a set of long-term and coordinated surveys that together cover the continental shelf and upper slope of most of the British Columbia coast. The other surveys are the Queen Charlotte Sound (QCS) survey, the Hecate Strait (HS) survey, the West Coast Vancouver Island (WCVI) survey, and the Strait of Georgia (SOG) survey. The objectives of these surveys are to provide fishery independent abundance indices of all demersal fish species available to bottom trawling and to collect biological samples of selected species. The survey follows a random depth-stratified design and the sampling units are 2 km by 2 km blocks. The synoptic bottom trawl surveys are conducted by Fisheries and Oceans Canada (DFO) in collaboration with the Canadian Groundfish Research and Conservation Society (CGRCS), a non-profit society composed of participants in the British Columbia commercial groundfish trawl fishery. The Queen Charlotte Sound and West Coast Haida Gwaii surveys are conducted under collaborative agreements, with the CGRCS providing chartered commercial fishing vessels and field technicians, while DFO provides in-kind contributions for running the surveys including personnel and equipment. The Hecate Strait, West Coast Vancouver Island, and Strait of Georgia surveys are conducted by DFO and have typically taken place on a Canadian Coast Guard research vessel. Until 2016 this vessel was the CCGS W.E. Ricker. From 2021 onwards, this vessel was the CCGS Sir John Franklin. In years when a coast guard vessel has not been available, the Hecate Strait, West Coast Vancouver Island, and Strait of Georgia surveys have taken place on chartered industry vessels. Data from these surveys are also presented in the groundfish data synopsis report (Anderson et al. 2019). Effort This table contains information about the survey trips and fishing events (trawl tows/sets) that are part of this survey series. 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, as well as information that can be used to calculate fishing effort (duration) and swept area. All successful fishing events are included, regardless of what was caught. Catch This table contains the catch information from successful fishing events. Catches are identified to species or to the lowest taxonomic level possible. Most catches are weighed, but some are too small (“trace” amounts) or too large (e.g. very large Big Skate). The unique trip identifier and set number are included so that catches can be related to the fishing event information (including capture location). Biology This table contains the available biological data for catches which were sampled. Data may include any or all of length, sex, weight, age. Different length types are measured depending on the species. Age structures are collected when possible for species where validated aging methods exist and are archived until required for an assessment; therefore, all existing structures have not been aged at this time. The unique trip identifier and set number are included so that samples can be related to the fishing event and catch information. Biomass This table contains relative biomass indices of species that have been captured in every survey of the time series. The coefficient of variation and bootstrapped 95% confidence intervals are provided for each index. The groundfish data synopsis report (Anderson et al. 2019) provides an explanation of how the relative biomass indices are derived. Note that we do not calculate a biomass index for the 2014 West Coast Haida Gwaii survey, as this survey was incomplete due to operational problems.
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Catch, effort, location (latitude, longitude), relative abundance indices, and associated biological data from groundfish multi-species bottom trawl surveys in West Coast Vancouver Island. Introduction The West Coast Vancouver Island (WCVI) synoptic bottom trawl survey was first conducted in 2004, The survey was repeated every even year until 2018. The 2020 survey was postponed to 2021 due to the COVID-19 pandemic. This survey is one of a set of long-term and coordinated surveys that together cover the continental shelf and upper slope of most of the British Columbia coast. The other surveys are the Queen Charlotte Sound (QCS) survey, the Hecate Strait (HS) survey, the West Coast Haida Gwaii (WCHG) survey, and the Strait of Georgia (SOG) survey. The objectives of these surveys are to provide fishery-independent abundance indices of all demersal fish species available to bottom trawling and to collect biological samples of selected species. The survey follows a random depth-stratified design and the sampling units are 2 km by 2 km blocks. The synoptic bottom trawl surveys are conducted by Fisheries and Oceans Canada (DFO) in collaboration with the Canadian Groundfish Research and Conservation Society (CGRCS), a non-profit society composed of participants in the British Columbia commercial groundfish trawl fishery. The Queen Charlotte Sound and West Coast Haida Gwaii surveys are conducted under collaborative agreements, with the CGRCS providing chartered commercial fishing vessels and field technicians, while DFO provides in-kind contributions for running the surveys including personnel and equipment. The Hecate Strait, West Coast Vancouver Island, and Strait of Georgia surveys are conducted by DFO and have typically taken place on a Canadian Coast Guard research vessel. Until 2016 this vessel was the CCGS W.E. Ricker. From 2021 onwards, this vessel was the CCGS Sir John Franklin. In years when a coast guard vessel has not been available, The Hecate Strait, West Coast Vancouver Island, and Strait of Georgia surveys have taken place on chartered industry vessels. Data from these surveys are also presented in the groundfish data synopsis report (Anderson et al. 2019). Effort This table contains information about the survey trips and fishing events (trawl tows/sets) that are part of this survey series. 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, as well as information that can be used to calculate fishing effort (duration) and swept area. All successful fishing events are included, regardless of what was caught. Catch This table contains the catch information from successful fishing events. Catches are identified to species or to the lowest taxonomic level possible. Most catches are weighed, but some are too small (“trace” amounts) or too large (e.g. very large Big Skate). The unique trip identifier and set number are included so that catches can be related to the fishing event information (including capture location). Biology This table contains the available biological data for catches which were sampled. Data may include any or all of length, sex, weight, age. Different length types are measured depending on the species. Age structures are collected when possible for species where validated aging methods exist and are archived until required for an assessment; therefore, all existing structures have not been aged at this time. The unique trip identifier and set number are included so that samples can be related to the fishing event and catch information. Biomass This table contains relative biomass indices of species that have been captured in every survey of the time series. The coefficient of variation and bootstrapped 95% confidence intervals are provided for each index. The groundfish data synopsis report (Anderson et al. 2019) provides an explanation of how the relative biomass indices are derived.
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Catch, effort, location (latitude, longitude), relative abundance indices, and associated biological data from groundfish multi-species bottom trawl surveys in Strait of Georgia. Introduction The Strait of Georgia (SOG) synoptic bottom trawl survey was conducted in 2012 and 2015. This survey is one of a set of long-term and coordinated surveys that together cover the continental shelf and upper slope of most of the British Columbia coast. The other surveys are the Queen Charlotte Sound (QCS) survey, the Hecate Strait (HS) survey, the West Coast Vancouver Island (WCVI) survey and the West Coast Haida Gwaii (WCHG) survey. The survey was not impacted by the COVID-19 pandemic. The objectives of these surveys are to provide fishery independent abundance indices of all demersal fish species available to bottom trawling and to collect biological samples of selected species. The surveys follow a random depth-stratified design and the sampling units are 2 km by 2 km blocks. The synoptic bottom trawl surveys are conducted by Fisheries and Oceans Canada (DFO) in collaboration with the Canadian Groundfish Research and Conservation Society (CGRCS), a non-profit society composed of participants in the British Columbia commercial groundfish trawl fishery. The Queen Charlotte Sound and West Coast Haida Gwaii surveys are conducted under collaborative agreements, with the CGRCS providing chartered commercial fishing vessels and field technicians, while DFO provides in-kind contributions for running the surveys including personnel and equipment. The Hecate Strait, West Coast Vancouver Island, and Strait of Georgia surveys are conducted by DFO and have typically taken place on a Canadian Coast Guard research vessel. Until 2016 this vessel was the CCGS W.E. Ricker. From 2021 onwards, this vessel was the CCGS Sir John Franklin. In years when a coast guard vessel has not been available, the Hecate Strait, West Coast Vancouver Island, and Strait of Georgia surveys have taken place on chartered industry vessels. Data from these surveys are also presented in the groundfish data synopsis report (Anderson et al. 2019). Effort This table contains information about the survey trips and fishing events (trawl tows/sets) that are part of this survey series. 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, as well as information that can be used to calculate fishing effort (duration) and swept area. All successful fishing events are included, regardless of what was caught. Catch This table contains the catch information from successful fishing events. Catches are identified to species or to the lowest taxonomic level possible. Most catches are weighed, but some are too small (“trace” amounts) or too large (e.g. very large Big Skate). The unique trip identifier and set number are included so that catches can be related to the fishing event information (including capture location). Biology This table contains the available biological data for catches which were sampled. Data may include any or all of length, sex, weight, age. Different length types are measured depending on the species. Age structures are collected when possible for species where validated aging methods exist and are archived until required for an assessment; therefore, all existing structures have not been aged at this time. The unique trip identifier and set number are included so that samples can be related to the fishing event and catch information. Biomass This table contains relative biomass indices of species that have been captured in every survey of the time series. The coefficient of variation and bootstrapped 95% confidence intervals are provided for each index. The groundfish data synopsis report (Anderson et al. 2019) provides an explanation of how the relative biomass indices are derived.