National Coral Reef Monitoring Program: Stratified Random Surveys (StRS) of Coral Demography (Adult and Juvenile Corals) across the Pacific Remote Island Areas from 2014 to 2018

The data described here result from benthic coral demographic surveys within belt transects of specified length and width for two life stages (juveniles and adults) across the islands and atolls of the Pacific Remote Island Areas from 2014 to 2018. The data provide information on adult coral colony counts, morphology, size, partial mortality (old and recent dead), presence and causation of disease and other compromised health conditions, including bleaching. Juvenile colony surveys include morphology and size. Taxonomic identification of adult colonies is to the species level and genus level for juveniles.

A two-stage stratified random sampling (StRS) design was employed to survey the coral reef ecosystems of the Pacific Remote Island Areas from 2014 to 2017, and starting in 2018 a one-stage StRS design was employed. 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 (i.e., shallow: >0–6 m; mid-depth: >6–18 m; and deep: >18–30 m), as well as reef zone (i.e., forereef, backreef, lagoon, and protected slope; the latter three only at Johnston and Kingman). Sampling effort allocation was determined based on strata area and sites randomly located within strata. The StRS design effectively reduces estimate variance through stratification using environmental covariates and by sampling more sites rather than more transects per site. Therefore, site-level estimates and site-to-site comparisons should proceed with caution.

The data were collected as part of the NOAA Pacific Islands Fisheries Science Center (PIFSC) and Ecosystem Sciences Division (ESD; formerly the Coral Reef Ecosystem Division) led National Coral Reef Monitoring Program (NCRMP) missions around the islands and atolls of the Pacific Remote Island Areas from 2014 to 2018.