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Benthic Surveys in Vatia, American Samoa: comprehensive assessment of coral demography (adult and juvenile corals) from belt transect surveys in 2015 and 2020

Published by Pacific Islands Fisheries Science Center | National Oceanic and Atmospheric Administration, Department of Commerce | Catalog Last Checked: August 02, 2026 at 11:19 PM | Dataset Last Updated: January 01, 2017 at 12:00 AM
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 2015, and 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 2015, the survey implemented a two-stage stratified random sampling (StRS) design to assess the Vatia coral reef community, and a one-stage StRS design in 2020. 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.

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31090 Eutrophication Impacts on Coral Ecosystem Health in Vatia, American Samoa Numeric Data Sets > Biology EARTH SCIENCE > Biosphere > Zoology > Corals EARTH SCIENCE > Biosphere > Zoology > Corals > Coral Diseases EARTH SCIENCE > Biosphere > Zoology > Corals > Coral Mortality EARTH SCIENCE > Biosphere > Zoology > Corals > Reef Damage Assessment > Pollution EARTH SCIENCE > Biosphere > Zoology > Corals > Reef Monitoring and Assessment

Complete Metadata
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accessLevel non-public
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describedByType application/octet-steam
description 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 2015, and 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 2015, the survey implemented a two-stage stratified random sampling (StRS) design to assess the Vatia coral reef community, and a one-stage StRS design in 2020. 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.
distribution 
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    "description": "Coral demographic data of adult corals from belt transect surveys conducted by the NOAA Coral Reef Ecosystem Program (CREP) in Vatia Bay, Tutuila, American Samoa in 2015.",
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    "description": "Draft Coral Reef Ecosystem Program - Standard Operating Procedures: Rapid Ecological Assessment (REA) Benthic Survey Data Collection - latest draft as of March 21, 2016. Refer to the Methodology - Benthic Survey sections only for the survey methodology details, as the other components are not relevant to this particular set of non-RAMP surveys.",
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identifier https://data.noaa.gov/waf/NOAA/nmfs/pifsc/iso/xml/30771.xml
issued 2017-01-01T00:00:00.000+00:00
keyword 
[
  "31090",
  "Eutrophication Impacts on Coral Ecosystem Health in Vatia, American Samoa",
  "Numeric Data Sets > Biology",
  "EARTH SCIENCE > Biosphere > Zoology > Corals",
  "EARTH SCIENCE > Biosphere > Zoology > Corals > Coral Diseases",
  "EARTH SCIENCE > Biosphere > Zoology > Corals > Coral Mortality",
  "EARTH SCIENCE > Biosphere > Zoology > Corals > Reef Damage Assessment > Pollution",
  "EARTH SCIENCE > Biosphere > Zoology > Corals > Reef Monitoring and Assessment",
  "EARTH SCIENCE > Biosphere > Zoology > Corals > Reef Monitoring and Assessment > Baseline studies",
  "EARTH SCIENCE > Biosphere > Zoology > Corals > Reef Monitoring and Assessment > Benthos Analysis > Transect Monitoring > Belt Transect",
  "EARTH SCIENCE > Biosphere > Zoology > Corals > Reef Monitoring and Assessment > Coral Colony Size and Condition",
  "EARTH SCIENCE > Biosphere > Zoology > Corals > Reef Monitoring and Assessment > In Situ Biological",
  "EARTH SCIENCE > Oceans > Coastal Processes > Coral Reefs",
  "EARTH SCIENCE > Oceans > Coastal Processes > Coral Reefs > Coral Reef Ecology",
  "EARTH SCIENCE > Oceans > Coastal Processes > Coral Reefs > Coral Reef Ecology > Benthic biology",
  "EARTH SCIENCE > Oceans > Marine Biology > Coral",
  "EARTH SCIENCE > Oceans > Marine Biology > Coral Communities",
  "CORAL",
  "CORAL - CENSUS",
  "CORAL - COLONY SIZE",
  "CORAL - SPECIES IDENTIFICATION",
  "survey - biological",
  "survey - coral reef",
  "survey - swimmer/diver",
  "Coral Reef Conservation Program",
  "US DOC; NOAA; NMFS; Pacific Islands Fisheries Science Center; Ecosystem Sciences Division; Coral Reef Ecosystem Program",
  "COUNTRY/TERRITORY > United States of America > American Samoa > Tutuila Island > Vatia Bay (14S170W0028)",
  "OCEAN BASIN > Pacific Ocean > Tutuila Island > Vatia Bay (14S170W0028)",
  "South Pacific Ocean",
  "CRED",
  "CREP",
  "Coral Reef Ecosystem Division",
  "Coral Reef Ecosystem Program",
  "ESD",
  "Ecosystem Sciences Division",
  "PIFSC",
  "Pacific Islands Fisheries Science Center",
  "Vatia",
  "DOC/NOAA/NMFS/PIFSC > Pacific Islands Fisheries Science Center, National Marine Fisheries Service, NOAA, U.S. Department of Commerce",
  "Benthic Missions"
]
landingPage https://www.fisheries.noaa.gov/inport/item/30771
language 
[]
license https://creativecommons.org/publicdomain/zero/1.0/
modified 2017-01-01T00:00:00.000+00:00
publisher 
{
  "name": "Pacific Islands Fisheries Science Center",
  "@type": "org:Organization"
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rights otherRestrictions, unclassified
spatial -170.66666666667,-14.25138888889,-170.67555555556,-14.24305555556
temporal 2015-11-02T00:00:00+00:00/2015-11-12T00:00:00+00:00
theme 
[
  "geospatial"
]
title Benthic Surveys in Vatia, American Samoa: comprehensive assessment of coral demography (adult and juvenile corals) from belt transect surveys in 2015 and 2020

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