Gearing up: Methods for quantifying gear density for fixed-gear commercial fisheries in the U.S. Atlantic
Data files
Oct 17, 2024 version files 3.25 MB
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JulianDays.csv
6.19 KB
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MapRef.Rdata
2.65 MB
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MapRefCellStatus.Rdata
334.23 KB
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README.md
6.93 KB
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StatAreas.dbf
4.54 KB
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StatAreas.prj
145 B
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StatAreas.shp
191.92 KB
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StatAreas.shx
604 B
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vms_data_example.RData
17.78 KB
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vtr_data_example.Rdata
41.67 KB
Abstract
Fixed-gear commercial fisheries are unique due to their occupancy nature, claiming areas of the ocean for discrete periods. As space conflicts arise from competing ocean uses, there is an increased need to understand and categorize fixed-gear fisheries to incorporate into marine spatial planning (MSP) efforts. We used fishery-dependent data and input from stakeholders to discern fleet dynamics of all gillnet and trap/pot fisheries in U.S. waters of the Northwest Atlantic Ocean. A Fixed-Gear Fishery Layer (FGFL) was developed combining fishery subgroups that were categorized around gear type, gear configuration, and species landed. Fishing effort from each subgroup was spatially allocated onto a 1 sq nm (1.9 sq km) grid using methods that relied on the level of detail available from trip reporting and monitoring, each with differing degrees of spatial resolution. This stepwise process allowed trips reported with minimal spatial detail to be included while not compromising trips where greater spatial precision existed. We demonstrate how the FGFL has been used for two MSP projects focused on protected species conservation and wind energy development.
https://doi.org/10.5061/dryad.37pvmcvvf
Description of the data and file structure
These files consist primarily of simulated fishery dependent data (actual vessel trip report (VTR) and vessel monitoring system (VMS) data could not be shared due to confidentiality restrictions) and R code. The intent of providing this code and data is to demonstrate our methods for allocating fishing gear densities spatially and temporally using fisheries dependent data sources. The user would likely take the data structure and code functions and adapt it to their own location specific details and alter it to adapt their data. The main fishery dependent data provided here are example fisheries VTR (vtr_data_example.Rdata) and VMS data (vms_data_example.Rdata). Our methods are carried out in R with a main code file (BuildFGFLMethods.R) which sources an additional file (InputDevFun.R) that contains functions for allocating fishing gear by four different methods - VMS locations, reported VTR coordinates, depth, and statistical reporting area. Additional data files include a fisheries management statistical reporting area shapefile (StatAreas) and a MapRef grid used as a spatial reference for relating all of the fisheries and management details along with basic spatial details specific to our work in the Northwest Atlantic region (e.g. depth, distance from shore). The StatAreas shapefile is publicly available at https://www.northeastoceandata.org/data-download/?#CommercialFishing and the depth within our MapRef grid was obtained by overlaying locations on a U.S. Coastal Relief Model that is also publicly available at https://www.ncei.noaa.gov/products/coastal-relief-model.
Files and variables
File: vtr_data_example.Rdata
Description: R data.frame containing simulated vessel trip report data.
Variables
- Fishery: uses singular example fishery (ExampleFGFishery) but could identify different fleets or fishery types
- VesselKey: a unique identifier for classifying certain vessel or fleet types to group similar sized vessels and fishing configurations
- AreaKey: identifies the Greater Atlantic Statistical Reporting Area where the trip occurred
- Year: numeric year
- Month: numerical month of the year
- Depth: numerical water depth (meters)
- DistanceFromShore: numerical distance in nautical miles from coastline
- GearFished: numerical value for total number of gear units fished (e.g. traps, nets)
- GearPerString: average number of gear units per string/trawl
- EndlinesPerString: number of endlines used in a string/trawl
- GearHeight: numerical height (meters) of gear unit (e.g. net height)
- GearLength: numberical length (meters) of gear unit (e.g. net length)
- Soak: numerical duration that gear remains in the water (hours)
- ReportId: unique identifier of the trip report
- HullNum: unique identifier of a given vessel
- Latitude: decimal degree latitude coordinate
- Longitude: decimal degree longitude coordinate
File: vms_data_example.RData
Description: R data.frame containing simulated vessel monitoring system pings. Normally pings are recorded on a minute or hourly rate, but data has was pre-processed to determine fishing status and ping date/time was converted to month and year.
Variables
- Fishery: uses singular example fishery (ExampleVMSFishery) but could identify different fleets or fishery types
- Year: numeric year
- Month: numerical month of the year
- Status: indicator of vessel status (Fishing or Transitting)
- Rate: a numerical ping rate that can be used to determine effort (elapsed minutes between pings)
- Latitude: decimal degree latitude coordinate
- Longitude: decimal degree longitude coordinate
File: MapRef.Rdata
Description: R data.frame of grid cells with unique identifiers at high and low resolution and various spatial attributes relating to their location
Variables
- Index_HR: grid cell identifier corresponding to the high resolution (1 square nautical mile) grid
- Index_LR: grid cell identifier corresponding to the low resolution (10 square nautical miles) grid
- Region: region designation within the MapRef domain (GOM_GBK = Gulf of Maine and Georges Bank, MAB = Mid-Atlantic Bight, SE = Southeast, SNE = Southern New England)
- State: two digit character abbreviation for U.S. state designation
- StatArea: identifies the numeric Greater Atlantic Statistical Reporting Area where cell resides
- LMA: identifies the Lobster Management Area where cell resides
- StateFed: identifies whether cell is in state or federal waters
- Distance: numerical distance from coastline
- Depth: numeric water depth in meters
- Fathoms: numeric water depth in fathoms
- AreaKey: combines column StateFed and StatArea
- Longitude: decimal degree longitude coordinate
- Latitude: decimal degree latitude coordinate
File: MapRefCellStatus.Rdata
Description: R data.frame containing Availability status of each monthly MapRef grid cell.
Variables
- Index_HR: grid cell identifier corresponding to the high resolution (1 square nautical mile) in the MapRef grid
- Month: numerical month of the year
- Available: numeric value between 0 (cell is unavailable) and 1 (available the entire month)
Files: StatAreas.dbf, StatAreas.prj, StatAreas.shp, StatAreas.shx
Description: this group of files combines to form a shapefile of Greater Atlantic Region Statistical Reporting Areas. Individual files make up the feature attributes (.dbf), coordinate system (.prj), feature geometry (.shp), and index of feature geometry (.shx). These files are read in together with one line of R code that references the root name (StatAreas) and provide spatial boundaries for allocation of fishing gear when more precise coordinates are not reported.
File: JulianDays.csv
Description: spreadsheet associating Julian days of the year to the associated month and day.
Variables
- Day: numerical day of the month
- Month: numerical month of the year
- Julian: sequential day count from the beginning of the year
Code/software
RStudio version 2022.07.1 or later is used to run the R code (provided) and process data. R version 4.2.1 or later is required as well as packages:
dplyr (dplyr_1.1.2 or later)
raster (raster_3.6-23 or later)
sp (sp_2.0-0 or later)
sf (sf_1.0-14 or later)
ggplot2 (ggplot2_3.4.2 or later)
magrittr (magrittr_2.0.3 or later)
lubridate (lubridate_1.9.2 or later)
Access information
Due to data confidentiality restrictions, the data used in this manuscript are not publicly available. The data provided here are simulated example data.
Fixed-gear fisheries existing in the Northwest Atlantic from Maine to Florida were summarized and allocated spatiotemporally based on the level of spatial precision in trip reports and vessel monitoring data. While the data used in the manuscript is not publicly available due to confidentiality restrictions, we provide simulated example fisheries trip reports (vtr_data_example.Rdata) and vessel monitoring system data (vms_data_example.Rdata) to demonstrate the methods described in the manuscript. These methods for allocating this example fixed-gear fisheries data are available and carried out in R and may be adapted to other areas and data worldwide. A central part of the methods utilizes a gridded data frame (MapRef.Rdata) that summarizes spatial variables within each grid cell and acts as a reference to fisheries data in the allocation process. This file is specific to the U.S. Atlantic waters, but similar grids could be generated for a given study area. Additional data files include shapefiles and other spatial and supporting data used in the methods and described in the R code and manuscript. The BuildFGFLMethods.R file is the main code used to perform the analysis.