Current extent and restoration opportunity shapefiles for blue carbon habitats in Aotearoa New Zealand (mangrove, saltmarsh, seagrass)

Shapefiles of current extent and restoration/carbon-sequestration opportunity for New Zealand's three blue carbon habitats (mangrove, saltmarsh, seagrass), supporting Bulmer et al. (2024), "Blue carbon habitats in Aotearoa New Zealand—opportunities for conservation, restoration, and carbon sequestration," Restoration Ecology 32(7):e14225. All layers are in NZGD2000 / New Zealand Transverse Mercator (EPSG:2193). Folder structure: Regional_all_habitats: 16 files, one per NZ regional council area, each containing all habitat classes present in that region (dissolved by class, attributes Cl and SUM_Area in hectares). National_by_habitat: three national files (Mangroves_National, Saltmarsh_National, Seagrass_National), each merging that class's polygons across all 16 regions. Current national extents: mangrove 30,533 ha, saltmarsh 20,932 ha, seagrass 61,340 ha. Opportunity_BC_regions: 16 regional restoration/carbon-sequestration opportunity layers, gridcodes corresponding to tidal zone (1–2 seagrass, 3 mangrove, 4 saltmarsh). Opportunity_BC_national: national opportunity layers split by tidal zone (Zone 4, and Zones 1–3 combined), totalling approximately 87,861 ha of opportunity area.