Benthic surveys along a water quality gradient in Aua, American Samoa: comprehensive assessment of coral demography (adult and juvenile corals) from belt transect surveys in 2022

This metadata record describes the coral demographic data of Aua Reef, American Samoa, generated from observations by divers of the Ecosystem Sciences Division (ESD) of the NOAA Pacific Islands Fisheries Science Center (PIFSC). Benthic coral demographic surveys were conducted within belt transects of specified length and width for two life stages (juveniles and adults) in Aua, American Samoa in September 2022. Surveys were conducted at 18 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 Aua Reef 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 focal point of this project was to establish a comprehensive biological, water quality, and carbonate chemistry baseline for Aua reef. This work aims at identifying measurable spatial differences in the structure and composition of the benthic and coral community at Aua that can be explained by measurable spatial patterns of water quality (nutrients and sediments) and water carbonate chemistry (pH and Alkalinity). This work is of fundamental importance for the development of the Aua Watershed Management Plan, and will enable Federal and jurisdictional resource managers to more effectively assess the effectiveness of watershed management actions reducing land-based pollution and impacts to the adjacent coral reef ecosystems.

This project builds on prior baseline and status and trends assessments conducted in 2012, 2015, and 2020 in Faga'alu Bay (U.S. Task Force watershed priority site) and Vatia (Territorial priority watershed) to address National and Jurisdictional goals to reduce land-based sources of pollution impacts in coral reef ecosystems.

This baseline assessment for land-based sources of pollution on Aua reef is part of a larger CRCP-funded project ID 31303: "Linking watershed management activities to reef health in American Samoa".

CTD profiles and water samples also were collected as part of this baseline assessment for the analysis of particulate and dissolved nutrients, total suspended solids, chlorophyll-a, and seawater pH and Alkalinity. These data are documented and archived separately.

Raw data include individual colony records with the corresponding physical data which reflect the description of the site.

An individual colony record for adult corals includes colony species/genus identification, morphology, maximum diameter (centimeter), percent old dead, percent recent dead, cause of recent dead general category, cause of recent dead specific category, condition, extent and severity. https://www.fisheries.noaa.gov/inport/item/68174

Juvenile coral colony records include colony species/genus identification, morphology, and size information (cm).

https://www.fisheries.noaa.gov/inport/item/68175

The physical record for juvenile and adult corals includes the following: region, island, site, date (day, month, year), latitude (decimal degrees), longitude (decimal degrees), transect, segment, segment length, segment width, minimum depth (feet), and maximum depth.

While every effort has been made to ensure that these data are accurate and reliable within the limits of the current state of the art, NOAA cannot assume liability for any damages caused by errors or omissions in the data, nor as a result of the failure of the data to function on a particular system. NOAA makes no warranty, expressed or implied, nor does the fact of distribution constitute such a warranty.

Aua reef, Tutuila, American Samoa

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NOAA Coral Reef Ecosystem Sciences Division (ESD) Data Sharing Recommendations, version 9.0 updated August 12, 2015:

The ESD welcomes the opportunity to collaborate on research issues contributing to the scientific basis for better management of marine ecosystems. The ESD has a very diverse set of field activities that generates large volumes of data using an array of data collection protocols.

The following recommendations are for your consideration as you use this data:

1) Data analyses should take all field exigencies into account. The most effective way to do this would be active collaboration with ESD principal investigators.

2) In all presentations, product releases, or publications using data generated by ESD, proper acknowledgement of both ESD and the individuals responsible for data collection is expected. Citing the DOI (if available) is preferred, a non-DOI example is listed below.

3) If you collect or generate data for the same study areas, ESD requests that you share relevant information on complimentary data collections.

4) Those receiving data are strongly urged to inform the ESD Data Management Team of any errors and discrepancies that are discovered during the course of using these data. They are further urged to bring to the attention of the Team all problems and difficulties encountered in using these data. This information is necessary in order to improve the collections and to facilitate more efficient and economical data processing and retrieval. The users are asked to supply copies of any missing data that may be located, and to provide information as to significant subsets and special aggregations of data that are developed in using the material provided.

Example citation:

"This publication makes use of data products provided by the Coral Reef Ecosystem Sciences Division (ESD), Pacific Islands Fisheries Science Center (PIFSC), National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration (NOAA), with funding support from the NOAA Coral Reef Conservation Program (CRCP). The analysis and interpretations presented here are solely that of the current authors."

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

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Please cite NOAA Ecosystem Sciences Division (ESD) when using the data.

Example

Cite as: Vargas-Angel, Bernardo; Coral Reef Ecosystem Program; Pacific Islands Fisheries Science Center (2023). Benthic Surveys in Aua, American Samoa: comprehensive assessment of coral demography (adult and juvenile corals) from belt transect surveys in 2022. NOAA National Centers for Environmental Information.

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PIFSC Oracle database views: v0_coral_obs_e and v0_coral_obs_f (date and location selection criteria required to subset the dataset)

Observations were made by experienced benthic survey personnel who have been trained, undergone a series of calibration surveys and coral taxon identification testing, and have met a set of minimum standards for colony assessment and taxon identification in each region.

Handheld GPS units were used to locate random sites and mark site locations.

Handheld GPS units were used to locate sites and mark site locations.

The taxon code AAAA is included where the segment was surveyed and no individual colonies were found in both the juvenile and adult colony records. These are true zeros. The value -9 is a placeholder or missing value for the fields: colony length, colony width (juveniles), extent, and severity. The value -1 is included where a coral colony is a fragment.

While colony lengths are derived from physical measurements, recent and old mortality and disease extent are visual estimates; surveyors calibrate to reduce inter-observer bias

Site GPS location and depth are appropriately collected to allow spatiotemporal comparisons.

Complete. All planned demographic data were collected.

Hard bottom habitats including backreef and forereef were surveyed.

Only shallow water (0 to 6 meter depth range) hard-bottom habitats are surveyed. The survey sites were randomly selected using a systematic process based on available habitat and bathymetric data.

Survey methods were consistent across all sites.

The quality control occurred at two major stages - 1) data entry and 2) data management. Data entry quality control included both review and manual error correction steps. Data management quality control included several standard error queries followed by correction prior to ingestion into Oracle database.

NOAA IRC and NOAA Fisheries ITS resources and assets.

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) following the same protocol to that established by the NOAA National Coral Reef Monitoring Program (NCRMP).