In 2004, the Environmental Protection Agency (EPA) Environmental Monitoring and Assessment Program (EMAP) National Coastal Assessment (NCA), coordinated through the Gulf Ecology Division, conducted a comprehensive survey of the condition of estuarine resources in American Samoa. The survey sampled 49 stations on islands of Tutuila, Aunu'u Ofu, Olosega, Ta'u during April and August, 2004. The WATER QUALITY MEASUREMENTS data set contains two types of data: hydrologic profile water quality information resulting from in-field observations of physical data and water quality information resulting from laboratory examination of water quality samples for nutrient analyses. The SEDIMENT CHEMISTRY data set contains sediment contaminant information resulting from laboratory examination of samples collected at sites. Each record reports the contaminant name and its associated measured concentration, date site was visited, and the group that collected the data. Only one grab per site was required by the program. The SEDIMENT GRAIN data set contains sediment grain analyses information resulting from laboratory examination of samples collected at sites visited during probability surveys. Each record reports the sediment component and its associated measured concentration, date site was visited, and the group that collected the data. Only one grab per site was required by the program.

In-situ nearshore seawater measurements of dissolved radon and water level were used to determine the advection rate of groundwater onto the fringing reef off Ofu, American Samoa.

Geochemical analysis of coastal springs and possible source waters were conducted in the National Park Service's National Park of American Samoa (NPS-NPSA) Ofu Island unit. Water samples were analyzed for dissolved nutrients, nitrate isotopes (delta-18-O and delta-15-N). Algae samples were collected and analyzed for delta-15-N and delta-13-C values.

Time series data of wave height and water surface elevation were acquired for 399 days at four locations on the southern reef of Ofu, American Samoa, in support of a study on submarine groundwater dynamics on this reef within the National Park of American Samoa’s Ofu Unit. The relative placement of sensors on the reef were as follows: OFU20E03 – mid reef at East site; OFU20E04 – inner reef at East site; OFU20W03 – mid reef at West site; OFU20W04 – inner reef at West site.

To support a long-term NOAA Coral Reef Conservation Program (CRCP) for sustainable management and conservation of coral reef ecosystems, from 2010-02-17 to 2010-03-23, reef fish assessment surveys were conducted, as a part of Rapid Ecological Assessments (REA), during the Pacific Reef Assessment and Monitoring Program (RAMP) Cruise HA1001 in the American Samoa region by the Coral Reef Ecosystem Division (CRED) at the NOAA Pacific Islands Fisheries Science Center (PIFSC). During the cruise, 30 REA sites were surveyed at Ofu & Olosega in the American Samoa region. At each REA site, fish biologists entered the water and conducted a fine-scale (~700 m^2) and high degree of taxonomic resolution REA survey to assess and monitor species diversity, size distribution, and abundance of fish in shallow-water hard-bottom (less than 30 m) habitats. Reef fish assessment surveys were focused on cataloging the diversity (species richness), abundance (numeric density) and biomass (fish mass per unit area) of diurnally active reef fish assemblages. The stationary point count (SPC) method was used to quantify reef fish species. Two divers lay out a 30 m transect line, and position themselves at the 7.5 and 22.5 meter marks. The SPC biologist then records estimated size and abundance of all fish within a visually estimated 15-m diameter cylinder centered on the stationary diver (7.5-m radius, total area ~ 177m^2 per cylinder). The diver first spends 5 minutes identifying all fish species in the cylindrical area, then proceeds to count and estimate size (total length) for each in a series of "instantaneous" point counts or sweeps of the cylinder. Fish were identified at the species level, wherever possible. All reef-associated fish, including those in the water column, were surveyed. The survey time for each stationary point count survey was approximately 20 min and generally four stationary point count surveys (two per diver) were conducted at each fish REA site. After completing REA surveys, divers noted the presence, at the survey site, of any unusual fish species not counted during SPC counts, in order to facilitate species lists per location.

This data table includes in-situ near-shore seawater measurements of excess radon (Rn-222), tide and crater lake water levels and salinity collected in Kalaupapa, Moloka'i, Hawaii.