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Sources, conventions, and derivation

Source: DATA_SOURCES.md

Source snapshots

inst/extdata/source-manifest.json records exact service URLs, selection queries, retrieval timestamps, raw-response SHA-256 checksums, and source feature counts. The raw responses are cached locally by data-raw/download.py; they are not committed. The release’s compressed R datasets are committed and work offline.

Layer Publisher and entry point Treatment
NMFS reporting areas NOAA AKRO Base_Map, layer 0 All source features retained, including both parts of code 523. Code 550 is retained in data but excluded by the default getter.
Groundfish statistical areas ADF&G Groundfish_Statistical_Areas_2001, layer 0 Full native attributes, with a six-character code added. Published series: 2001-present.
Groundfish registration areas ADF&G Commercial Fisheries Groundfish Registration Areas, layer 0 All eight areas, including source dates and agency codes.
Arctic and salmon West NOAA Management Areas ATB, layer 126 Selected by agency and site name, not unstable object IDs. Last-edited source fields in the inspected snapshot are April 2023.
Alaska land Natural Earth 1:10m states/provinces Alaska land polygon selected; no attempt to infer regulatory baselines.

Agency entry points: NOAA Alaska boundaries and ADF&G commercial GIS.

The ATB inventory provides broad-scale managed areas. Its predecessor is described in NOAA InPort 66840; that record’s older NMFS_Management_Areas endpoint required a token when inspected. AKsf uses the accessible, separately named ATB service above and records that actual URL. An InPort metadata-modification date does not update the polygon vintage.

What “following agency conventions” means

  • Reporting, registration, and statistical units remain distinct.
  • NMFS reporting codes remain three-character strings. ADF&G statistical codes are six-character strings in area_code; original numeric STAT_AREA remains.
  • ADF&G’s native registration, district, subdistrict, section, sector, fishery, federal-reporting, IFQ, waters, and FMP fields remain available. These are agency assignments, not crosswalks inferred from spatial overlap.
  • WATERS_CODE values FED, STATE, and INTL are respected. ADF&G groundfish data are not applied to all salmon or shellfish reporting contexts.
  • ADF&G geometry dates remain in the original Unix-millisecond representation. The snapshot is not a complete historical archive. No “as of” option is offered.
  • Source metadata may refer to NAD83 boundary definitions while the delivered service advertises WGS84. Imports request EPSG:4326 explicitly. AKsf then transforms with PROJ; it does not relabel coordinates as another datum.
  • EPSG:3338 is the package’s metre-based Alaska Albers default. Projection reduces dateline plotting problems; it does not remove datum or source-resolution limits.

FMP reference geometries

The NPFMC library identifies six FMPs. AKsf represents all six, with eight features because salmon has three areas. These are broad cartographic coverage polygons, not species-stock areas, EFH, seasonal closures, permitted fishing grounds, or independently certified legal boundaries. Cross-fishery overlap is expected.

  1. BSAI and GOA groundfish: dissolve only ADF&G statistical polygons whose WATERS_CODE is FED, grouped by FMP_AREA_CODE, then intersect with NOAA reporting polygons for the matching BS/AI or GOA region to trim statistical cells at the smooth offshore boundary. Do not dissolve the entire NOAA reporting layer: that would incorporate some state waters and international 550. BSAI FMP overview; GOA FMP overview.
  2. BSAI crab: the Crab FMP, section 3.1.2 and Figure 3-1, extends south of the Aleutians eastward to Scotch Cap Light, 164°44′36″ W. Combine BSAI federal coverage with the part of GOA federal coverage west of that meridian. Reusing only the BSAI groundfish polygon would miss the southern waters between 170° W and Scotch Cap.
  3. Scallop: combine federal BSAI and GOA coverage, consistent with the geographic description in section 4.1 of the Scallop FMP. Arctic waters are not added. This does not map the state’s scallop registration units or fishable scallop beds.
  4. Arctic: republish the NOAA ATB Arctic Closure polygon as reference coverage. The NPFMC Arctic page describes the area. The Arctic plan is not a substitute for salmon or halibut management; salmon coverage can overlap it.
  5. Salmon: use section 2.2 and Figures 1–2 of the October 2024 Salmon FMP. East is federal GOA coverage east of Cape Suckling (143°53.6′ W). Cook Inlet is federal ADF&G groundfish registration H coverage north of 59°46.15′ N, selecting the connected polygon containing an interior Cook Inlet point (152.4° W, 60° N). Registration H also includes waters outside Cook Inlet, so its other components are not included. West is the NOAA ATB “Salmon Management Area West” geometry, with Cook Inlet explicitly removed. The ATB source predates Amendment 16 and inherits its existing Prince William Sound and Alaska Peninsula exclusions. AKsf does not infer present fishing permissions from that inventory or claim those exclusions have been independently recertified. Source-vintage and shoreline differences can cause small slivers between NOAA and ADF&G products.

The NOAA ATB West inventory is retained as a traceable source rather than redrawing its complex coastal exclusions from a small-scale figure. Users needing boundary-sensitive salmon allocations should replace it with an agency-validated current product. All FMP features carry boundary_status = "cartographic_reference_not_regulatory" and a geometry_basis field.

Spatial processing and precision

data-raw/build-data.R is the complete derivation. Agency responses are requested as WGS84 GeoJSON without server-side simplification. Features are transformed to EPSG:3338, repaired with GEOS st_make_valid(), and returned to EPSG:4326 for the bundled source layers. Native attributes remain; geometry repair may split invalid components. FMP operations and area calculations occur in EPSG:3338. Meridians and parallels used for clipping are densified at no more than 0.01° intervals before projection. These masks only clip agency water polygons; they never replace the EEZ/coast with rectangles. No arbitrary coastline buffer defines state waters.

Source Shape_* attributes are untouched metadata and may use source CRS units. Use sf::st_area() on transformed geometry for new measurements; FMP area_km2 is computed in Alaska Albers. The build records geometry checks and R/library versions in inst/extdata. SHA-256 hashes cover the raw assembled GeoJSON bytes, not the transformed .rda bytes. Rebuilding against a changed live service is an intentional data update, not guaranteed reproduction of an earlier release.

Known gaps

This release includes no bathymetry, high-resolution NOAA shoreline, IPHC polygons, crab stock boundaries, species-specific closure calendar, or statewide salmon statistical-area compilation. Registration and statistical snapshots are the published groundfish series. FMP derivations have not been certified by the agencies. Validation tests establish code behavior, topology, and selected spatial relationships; they cannot prove legal equivalence to every FMP amendment.

NOAA closure vignette example

inst/extdata/closure-example contains two records from NOAA AKRO’s Habitat_Restrictions layer: GOA_Slope_HCA.htm and GOA_Coral_HPA.htm. Retrieved 2026-09-21; both retain the source annotation steve.lewis, akro, 01/19/15. This is a historical teaching snapshot, not a current closure inventory. Original attributes and service geometry requested in WGS84 are preserved. The adjacent manifest records IDs, query URL, retrieval time, and SHA-256; layer metadata is included. NOAA/AKRO is the source; this U.S. federal government data is not relicensed as AKsf code. Retain attribution and consult NOAA regulations and notices for current restrictions. Regenerate with data-raw/download-closure-example.py.