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Retrieve Global Fishing Watch Data

Source: R/splnr_get_gfw.R
splnr_get_gfw.Rd

The splnr_get_gfw function retrieves Global Fishing Watch (GFW) data and returns it as an sf (simple features) object. This function allows for flexible data queries based on geographical region, time range, and desired spatial and temporal resolutions.

Usage

splnr_get_gfw(
  region,
  start_date,
  end_date,
  temp_res,
  spat_res = "LOW",
  region_source = "EEZ",
  key = gfwr::gfw_auth(),
  cCRS = "EPSG:4326",
  compress = FALSE
)

Arguments

region

A character string specifying the name of the region (e.g., an EEZ name) or a numeric ID for the region, or an sf object if region_source is set to "USER_SHAPEFILE".

start_date

The start date for data retrieval, expected in "%Y-%m-%d" format (e.g., "2021-01-01").

end_date

The end date for data retrieval, expected in "%Y-%m-%d" format (e.g., "2022-12-31").

temp_res

The desired temporal resolution for the data. Must be one of: "DAILY", "MONTHLY", or "YEARLY".

spat_res

The desired spatial resolution for the data. Must be one of: "LOW" (0.1 degree) or "HIGH" (0.01 degree). Defaults to "LOW".

region_source

The source of the region definition. Must be one of: 'EEZ', 'MPA', 'RFMO', or 'USER_SHAPEFILE'. Defaults to "EEZ".

key

Your API token for the GFW API. If not provided, it attempts to authenticate using gfwr::gfw_auth(). See the GlobalFishingWatch vignette for details on obtaining a key.

cCRS

The Coordinate Reference System (CRS) to which the output sf object will be transformed. Defaults to "EPSG:4326".

compress

A logical value. If TRUE, the data will be compressed (aggregated) by coordinates, summing fishing hours for each unique location. If FALSE, the raw data points are returned. Defaults to FALSE.

Value

An sf object containing the requested GFW data. The structure of the sf object will vary depending on the compress and temp_res parameters.

Details

The possibilities offered by this function are extensively explained in vignette("GlobalFishingWatch").

This function shares many parameters with the get_raster function from the gfwr package, with the addition of cCRS for specifying the Coordinate Reference System of the output sf object.

Fishing activity data can be aggregated (group_by) by "FLAGANDGEARTYPE" by default, combining flags and gear types.

Notes:

  • Currently, the function is primarily designed for data within Exclusive Economic Zones (EEZs), but it can potentially be extended to specific Marine Protected Areas (MPAs) or RFMOs.

  • Days specified in the start_date and end_date variables are inclusive in the data recovery.

Examples

if (FALSE) { # \dontrun{
# Example: Retrieve yearly GFW data for Australia, transformed to a
# Mollweide projection (ESRI:54009) and compressed (aggregated) by location.
gfw_data <- splnr_get_gfw(
  region = 'Australia',
  start_date = "2021-01-01",
  end_date = "2022-12-31",
  temp_res = "YEARLY",
  cCRS = "ESRI:54009",
  compress = TRUE
)

# Example: Retrieve monthly GFW data for a specific EEZ ID,
# keeping individual time ranges and locations.
# Note: Replace 1000 with an actual EEZ ID if needed for testing.
gfw_data_monthly <- splnr_get_gfw(
  region = 1000, # Example numeric EEZ ID
  start_date = "2022-01-01",
  end_date = "2022-03-31",
  temp_res = "MONTHLY",
  region_source = "EEZ",
  compress = FALSE
)
} # }