Data Management Plan

The data described here are benthic habitat imagery (color-corrected photographs) from benthic photo-quadrat surveys conducted along transects at stratified random sites by the Pacific Islands Fisheries Science Center (PIFSC) Ecosystem Sciences Division (ESD)--formerly the Coral Reef Ecosystem Division--as part of the NOAA National Coral Reef Monitoring Program (NCRMP). The photo-quadrat surveys are part of Rapid Ecological Assessment (REA) surveys for corals and fish conducted during ESD-led NCRMP missions across the Hawaiian Archipelago in 2013, 2016, 2015, and 2019. In 2015, there was also a NCRMP (formerly known as RAMP) mission led by the Papahānaumokuākea Marine National Monument (PMNM) (HA1505) to the Northwestern Hawaiian Islands (NWHI).

A stratified random sampling (StRS) design was employed to survey the coral reef ecosystems across the Hawaiian Archipelago. 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, reef zone, and depth in all regions, as well as habitat structure type in the Main Hawaiian Islands. Allocation of sampling effort was proportional to strata area and variance in coral density. Sites were surveyed using photo-quadrats along transects to collect benthic imagery to ultimately produce estimates of relative abundance (percent cover), frequency of occurrence, benthic community taxonomic composition and relative generic richness.

The StRS design effectively reduces estimate variance through stratification using environmental covariates and by sampling more sites rather than sampling more transects at a site. Therefore, site-level estimates and site to site comparisons should be used with caution.

Main Hawaiian Islands (MHI), including Hawaii, Kauai, Maui, Oahu, Molokai, Niihau, Kahoolawe, and Lanai.

Northwestern Hawaiian Islands (NWHI), including French Frigate Shoals, Kure, Lisianki, and Pearl & Hermes.

Lineage Statement:
The stratified random sampling (StRS) design and benthic photoquadrat survey methodology, employed by the NOAA Ecosystem Sciences Division (ESD) from 2013 to 2019. Benthic imagery is collected at stratified random sites. These photos are color-corrected (if necessary) prior to analysis. The data management team also uses an optical validation script to re-name photos and enforce several validation checks.

Process Steps:

• A stratified random sampling (StRS) design was employed to survey the coral reef ecosystems through the U.S. Pacific regions. The survey domain encompassed the majority of the mapped area of reef and hard bottom habitats. The stratification scheme included island, reef zone, and depth in all regions, as well as habitat structure type in the Main Hawaiian Islands. The habitat structure types included simple, complex, and coral-rich. Depth categories of shallow (0-6 m), mid (> 6-18m) and deep (>18-30 m) were also incorporated into the stratification scheme. Allocation of sampling effort was proportional to strata area and variance in coral density . Sites were randomly selected within each stratum. A geographic information system (GIS) and digital spatial databases of benthic habitats (NOAA National Centers for Coastal Ocean Science NCCOS), reef zones (IKONOS satellite imagery, NDGC 1998) bathymetry (NDGC 1998, CREP benthic mapping data), and marine reserve boundaries (NOAA) were used to facilitate spatial delineation of the sampling survey domain, strata, and sample units. Map resolution was such that the survey domain could be overlain by a grid using a GIS with individual cells of size 50 m by 50 m in area. A one-stage sampling scheme following Cochran (1977) was employed. Grid cells containing hard-bottom reef habitats were designated as primary sample units (referred to as sites).
• Photoquadrat surveys were conducted by both the fish and benthic teams. Still photographs were collected to record the benthic community composition at predetermined points along the transect line with a high-resolution digital camera mounted on a pole. Overall, 30 photoquadrat images are collected at each site. The fish team conducts these surveys along one 30 meter transect that spans the length of two stationary point count (SPC) cylinders used to assess fish abundance (30 images total, Transect A). As of 2018, the benthic team conducts the photoquadrat surveys along one 30m transect, where one photo is taken every meter for a total of 30 photographs.
• To ensure consistency, images were color corrected using Adobe Lightroom if it appeared that the camera they were taken from was not properly white balanced in the field. Raw data include 30 benthic photographs per survey site. Included in the archive package is a list of survey sites, including region, island, site, date (day, month, year), latitude (dd), longitude (dd), minimum depth (ft), and maximum depth where photoquads were collected and unique image name. The file naming convention for each photo/image is [SITE]_[YEAR]_[TRANSECT]_[PHOTO_NUMBER].JPG (for example: TUT-903_2012_A_01.JPG).

The photos are reviewed by the diver for accuracy and usability. To ensure consistency, images were color corrected using Adobe Lightroom if it appeared that the camera they were taken from was not properly white balanced in the field. The data management team also uses a optical validation script to re-name photos and enforce several validation checks.

Data can be accessed online via the NOAA National Centers for Environmental Information (NCEI) Ocean Archive.

The images reside on a file server maintained and regularly backed up by PIFSC ITS.