Coral Reef Structural Complexity derived from Structure-from-Motion (SfM) imagery collected at Stratified-Random Sites (StRS) across the U.S. Pacific since 2019

The data described here are structural complexity estimates derived from Structure-from-Motion (SfM) benthic habitat imagery from diver transect surveys conducted at stratified-random sites (StRS) by the Pacific Islands Fisheries Science Center (PIFSC) Ecosystem Sciences Division (ESD) as part of the NOAA National Coral Reef Monitoring Program (NCRMP). The coral reef photos, collected by scuba divers, are used to generate 3-dimensional models, digital elevation models (DEMs) and orthomosaics using Agisoft Metashape photogrammetric software. The digital elevation models were analyzed in R studio to derive estimates of habitat structural complexity, using metrics such as: rugosity, fractal dimension, and height range, among others.   The source imagery is archived and described separately at https://www.fisheries.noaa.gov/inport/item/63095.
The SfM surveys are part of the Rapid Ecological Assessment (REA) surveys for corals and fish conducted during ESD-led NCRMP missions. Sites were imaged using underwater cameras along 3x20m (3x13m for sites deeper than 18m) transects across the U.S. Pacific Island areas beginning in 2019. Please refer to the Lineage section for SOPs -- 2019 and 2022 have slightly different processing steps. Complexity metrics were estimated for each site within five or six 4m2 DEM sampling plots, which can then be averaged for the site. Rugosity is measured as the ratio between surface area and planar area within a sampling plot, Fractal dimension is measured using the variation or standard deviation method (see Lineage section below), and height range is measured as the difference between the deepest and shallowest point  within a sampling plot.  
A stratified random sampling (StRS) design was employed to survey the coral reef ecosystems across the U.S. Pacific Regions (Hawaiian Archipelago, Mariana Archipelago, American Samoa, and the Pacific Remote Island Areas). The survey domain encompassed the majority of the mapped area of reef and hard bottom habitats in the 0-30 m depth range. The stratification scheme included island, sub-island sector, reef zone, and depth in all regions, as well as habitat structure type. Allocation of sampling effort was proportional to the strata hardbottom area. The StRS design effectively reduces estimated variance by sampling more sites with larger hardbottom area and variance.

Tags: 31360, 31525, 743, agisoft, aguihan, aguihan island (aguijan) (14n145e0006), aguihan island reefs, american samoa, american samoa (14s170w0000), aquatic habitat, asuncion island, asuncion island (19n145e0001), baker island, baker island (00n176w0001), bathymetry/seafloor topography, benthic, biosphere, central pacific ocean, cnmi, coastal processes, coastal waters of hawaii, complexity metrics, computer, coral, coral - census, coral mapping, coral reef, coral reef conservation program, coral reef ecology, coral reef ecosystem division, coral reef ecosystem program, coral reef studies, coral reefs, corals, country/territory, cred, crep, derived products, digital elevation model, doc/noaa/nmfs/pifsc, doc/noaa/nmfs/pifsc/esd, earth science, ecosystem sciences division, ecosystems, esd, fractal dimension, french frigate shoals (24n166w0001), geographic information, guam, guam (13n144e0000), hawaii, hawaii (21n160w0000, hawaii (21n160w0000), hawaii island, hawaii island (19n155w0003, hawaii island (19n155w0003), hawaiian islands, hawaiian islands (21n157w0027), height range, honolulu, howland island, howland island (00s176w0001, howland island (00s176w0001), jarvis island (00s160w0001), johnston atoll, johnston atoll (16n169w0001), kahoolawe island, kahoolawe island (20n156w0001), kalawao, kauai, kauai island, kauai island (22n159w0001, kauai island (22n159w0001), kingman reef (06n162w0001), kure atoll (28n178w0001), lanai island, lanai island (20n156w0002, lanai island (20n156w0002), line islands, lisianski island (25n173w0001), manu'a group, map images, mariana archipelago, marine biology, marine ecosystems, maug, maug island, maug island (20n145e0001), maui, maui island, maui island (20n156w0004, maui island (20n156w0004), micronesia, molokai island, molokai island (21n157w0001), national coral reef monitoring program, national marine fisheries service, niihau island, niihau island (21n160w0001), nmfs, noaa, noaa coral reef conservation program, north pacific ocean, northern mariana islands, northern mariana islands ( cnmi ) (18n146e0000), northwestern hawaiian islands, northwestern hawaiian islands (28n178w0000), numeric data sets, oahu (21n157w0003), oahu island, ocean, ocean basin, oceans, ofu island (14s169w0013), olosega island (14s169w0014), oscar elton sette, pacific islands fisheries science center, pacific national coral reef monitoring program, pacific ocean, pacific remote island areas, pagan, pagan island, pagan island (18n145e0001), palmyra atoll (05n162w0001), pearl and hermes reef (27n176w0001), photograph, photographic analysis, pifsc, reef, reef assessment and monitoring program, reef habitat, reef habitat complexity, reef monitoring and assessment, rose atoll (14s168w0001), rota, rota island, rota island ( luta ) (14n145e0007), rugosity, saipan, saipan island, saipan island (15n145e0002), sarigan island, sarigan island (16n145e0003), sfm, structure from motion, swains atoll (11s171w0001), ta'u island (14s169w0012), tinian, tinian island (14n145e0005), tinian island reefs, topography, tutuila island (14s170w0016), u.s. department of commerce, united states minor outlying islands, united states of america, us doc, usa minor outlying islands, wake atoll, wake atoll (19n167e0001), western pacific ocean, zoology
Organization: National Oceanic and Atmospheric Administration, Department of Commerce