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) in Fagaʻalu, American Samoa in 2020. 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. In 2020, the survey implemented a one-stage stratified random sampling (StRS) design to assess the Fagaʻalu coral reef community. 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 cardinal position (i.e., north and south), reef zone (i.e., backreef and forereef) and depth (i.e., shallow: >0–6 m and mid-depth: >6–18 m). 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-to-site comparisons should proceed with caution.

Jurisdictional managers have expressed concerns that nutrients from the village of Vatia, Tutuila, American Samoa, are having an adverse effect on the adjacent coral reef ecosystem. Excess nutrient loads promote increases in algal growth that can have deleterious effects on corals, such as benthic algae outcompeting and overgrowing corals. Nitrogen and phosphorus can also directly impact corals by lowering fertilization success, and reducing both photosynthesis and calcification rates. Land-based contributions of nutrients come from a variety of sources; in Vatia the most likely sources are poor wastewater management from piggeries and septic systems. NOAA scientists conducted benthic surveys to establish a baseline against which to compare changes in the algal and coral assemblages in response to land-based sources of pollution, including nutrient fluxes. 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) in Vatia Bay American Samoa in 2020. 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. In 2020, the survey implemented was a one-stage stratified random sampling (StRS) design to assess the Vatia coral reef community. 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 cardinal position (i.e., north and south) and depth (i.e., shallow: >0–6 m and mid-depth: >6–18 m). 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-to-site comparisons should proceed with caution.

Jurisdictional managers have expressed concerns that nutrients from the village of Vatia, Tutuila, American Samoa, are having an adverse effect on the adjacent coral reef ecosystem. Excess nutrient loads promote increases in algal growth that can have deleterious effects on corals, such as benthic algae outcompeting and overgrowing corals. Nitrogen and phosphorus can also directly impact corals by lowering fertilization success, and reducing both photosynthesis and calcification rates. Land-based contributions of nutrients come from a variety of sources; in Vatia the most likely sources are poor wastewater management from piggeries and septic systems. NOAA scientists conducted benthic surveys to establish a baseline against which to compare changes in the algal and coral assemblages in response to nutrient fluxes. The data described here were collected via belt transect surveys of coral demography (adult and juvenile corals) by the NOAA Coral Reef Ecosystem Program (CREP) according to protocols established by the NOAA National Coral Reef Monitoring Program (NCRMP). In 2015 data were collected at 18 stratified randomly selected sites in Vatia Bay. These data include: 1) an assessment of coral colony density and size-class distribution for the selected monitoring sites; 2) an assessment of coral recruitment at the monitoring sites; and 3) an evaluation of coral colony condition, including mortality, disease, bleaching, and evidence of sediment stress. These data can be accessed online via the NOAA National Centers for Environmental Information (NCEI) Ocean Archive. Additionally, photoquadrat benthic images were collected and analyzed for benthic cover composition (documented and archived separately). A brief report documenting the 2015 surveys conducted in Vatia and Fagaʻalu in Tutuila, American Samoa by the NOAA Coral Reef Ecosystem Program is in progress: Baseline Assessment of Coral Reef Community Structure and Demographics in Vatia and Fagaʻalu Bays, American Samoa.

This dataset includes coral demographic data of Nu'uuli Pala Lagoon and Backreef, American Samoa. Surveys were conducted by snorkelers from the Ecosystem Sciences Division (ESD) of the NOAA Pacific Islands Fisheries Science Center (PIFSC), in collaboration American Samoa's Department of Marine and Wildlife Resources and the Coral Reef Advisory Group. Benthic coral demographic surveys were conducted within belt transects of specified length and width for two life stages (juveniles and adults) in Nu'uuli Pala Lagoon and Backreef, American Samoa in November 2024. Surveys were conducted at 20 randomly-selected sites and provide information on adult coral colony counts, morphology, size, partial mortality (old and recent dead), presence 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 (where possible) and genus level for juveniles. The survey design and site selection of stratified-random sites (StRS) follows protocols established by the National Coral Reef Monitoring Program (NCRMP). Data from benthic surveys of Nu'uuli Pala Lagoon and Backreef establishes a comprehensive biological baseline for land-based sources of pollution impacts on benthic composition and coral demography. These efforts feed into the higher-level CRCP objectives by establishing an in-situ tracking system to assess the effects of management and mitigation strategies and activities in the target watersheds to reduce land-based sources of pollution impacts on coral reefs.

The data described here were collected in Fagaʻalu, American Samoa in 2013 and 2015 via belt transect surveys of coral demography (adult and juvenile corals) by the NOAA Coral Reef Ecosystem Program (CREP) according to protocols established by the NOAA National Coral Reef Monitoring Program (NCRMP). These data include: 1) an assessment of coral colony density and size-class distribution for the selected monitoring sites; 2) an assessment of coral recruitment at the monitoring sites; and 3) an evaluation of coral colony condition, including mortality, disease, bleaching, and evidence of sediment stress. These data can be accessed online via the NOAA National Centers for Environmental Information (NCEI) Ocean Archive. Additionally, coral demographic surveys were conducted in 2012 using the nearly similar pre-NCRMP belt-transect method, photoquadrat benthic images were collected in 2012 and 2015, and the 2015 images were analyzed for benthic cover composition (all documented and archived separately).

This data package includes benthic cover data of Aua Reef, American Samoa, produced from the analysis of benthic imagery performed by the Ecosystem Sciences Division (ESD) of the Pacific Island Fisheries Science Center (PIFSC), and funded by the Coral Reef Conservation Program (CRCP). Benthic imagery was collected at 18 randomly-selected sites during coral demographic surveys by the NOAA ESD during the 2022 fly-in mission to American Samoa (MP2206). After processing and sorting site photos, imagery was qualitatively analyzed using the web-based CoralNet image annotation tool. CoralNet projects random points on each image, and the benthic elements falling directly underneath each point are identified by trained scientists. The source imagery analyzed to produce benthic cover estimates are archived separately with the NOAA National Centers for Environmental Information (NCEI) in NCEI Accession 0270551.

The benthic cover data described here were generated from the quantitative analysis of photoquadrat benthic images using CoralNet image analysis software, whereby random points are projected on each image and the benthic elements falling directly underneath each point are identified. The images were collected at 18 stratified randomly selected sites in Vatia Bay in 2015 during belt transect surveys of coral demography by the Ecosystem Sciences Division (ESD) of the NOAA Pacific Islands Fisheries Science Center (PIFSC). The benthic cover data can be accessed online via the NOAA National Centers for Environmental Information (NCEI) Ocean Archive. The benthic images and coral demography data are described and archived separately.