National Coral Reef Monitoring Program: Shallow Water Conductivity-Temperature-Depth (CTD) Profiles for select locations across American Samoa from 2015 to 2023

The data described here result from near-shore shallow water Conductivity-Temperature-Depth (CTD) casts conducted at select sites around American Samoa as part of the ongoing National Coral Reef Monitoring Program (NCRMP). These surveys were conducted by the NOAA Pacific Islands Fisheries Science Center (PIFSC), Ecosystem Sciences Division (ESD; formerly the Coral Reef Ecosystem Division) during ESD-led NCRMP missions to American Samoa in 2015, 2018, and 2023. The CTD casts provide vertical profiles (30-m max depth, downcast only) of water column conductivity, temperature, pressure, with calculated depth, salinity, and water density.

The CTD (Sea-Bird Electronics, SBE19-plus in 2015 and 2018, RBR Concerto in 2023) was deployed from a small boat using a hand line and held just under the surface for 1 minute to cycle water through the instrument and tubing. Afterward, data were collected by lowering the CTD in profiling mode at an even pace (descent rate ~0.5 to 0.75 meters per second) to a maximum depth of 30 m. Data processing was performed using Sea-Bird Scientific SBE or RBR Ruskin Data Processing Software and the R package "oce".

CTD casts are conducted to characterize the spatial structure of the physical and chemical properties of the ocean environment influencing the living coral reef resources observed during NOAA National Coral Reef Monitoring Program (NCRMP) missions.

The NOAA National Coral Reef Monitoring Program (NCRMP) details a long term approach to provide an ecosystem perspective via monitoring climate, fish, benthic, and socioeconomic variables in a consistent and integrated manner. The NCRMP coordinates various NOAA Coral Reef Conservation Program (CRCP) biological, physical, and human dimensions activities into a cohesive NOAA-wide effort. Through the implementation of the NCRMP, NOAA is able to clearly and concisely communicate results of national-scale monitoring to national, state, and territorial policy makers, resource managers, and the public on a periodic basis.

NCRMP is a framework for conducting sustained observations of biological, climate, and socioeconomic indicators at 10 priority coral reefs across the U.S. and its territories. This integrated approach consolidates monitoring of coral reefs under a uniform method in the Pacific, Atlantic, Caribbean, and the Gulf of Mexico for the first time. NCRMP is funded by the Coral Reef Conservation Program (CRCP) and supported by NOAA Fisheries, NOAA National Centers for Coastal Ocean Science (NCCOS), NOAA's Atlantic Oceanographic & Meteorological Laboratory (AOML), NOAA Coral Reef Watch, and many other partners. The Ecosystem Sciences Division (ESD) at NOAA Fisheries is leading in-situ climate monitoring in the U.S. Pacific Islands Region.

The climate component of NCRMP in the Pacific provides a comprehensive view of climate change impacts on coral reef ecosystems and helps identify areas of resilience and vulnerability. The key indicators used to identify and monitor climate-driven trends include 1) thermal stress caused by changes in sea temperature, 2) ocean acidification resulting from changes in carbonate chemistry, and 3) ecological impacts by collecting data on coral growth rates, erosion, and community structure to understand the impacts of thermal stress and ocean acidification on the ecosystem. Each year, ESD scientists work closely with CRCP and partners during Reef Assessment and Monitoring Program (RAMP) missions to collect data using moored oceanographic and ecological instruments stationed at fixed sites in the Pacific Ocean, and water samples collected by divers. The in-situ data and satellite-based observations are also used in modeling efforts. Innovative analysis techniques are used to develop products that give fellow scientists, managers, decision makers and the public a better understanding of a region's resources and how they are changing over time.

Initially published in 2017. Updated in March 2021, and again in August 2024.

CTD data include metadata for each observation and conductivity, temperature, and pressure, with calculated depth, salinity and density.

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.

American Samoa, including Tutuila, Manu'a (Ofu, Olosega, and Ta'u), Rose Atoll, and Swains.

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

ESD welcomes the opportunity to collaborate on research issues contributing to the scientific basis for better management of marine ecosystems. 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 Ecosystem Science 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 Ocean Acidification Program (OAP). 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 PIFSC Ecosystem Sciences Division (ESD) when using the data.

Suggested Citation:

Ecosystem Sciences Division, Pacific Islands Fisheries Science Center, 2024: National Coral Reef Monitoring Program: Shallow Water Conductivity-Temperature-Depth (CTD) Profiles for select locations across American Samoa from 2015 to 2023, https://www.fisheries.noaa.gov/inport/item/36761.

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Raw CTD profile data are downloaded as .RSK or .HEX files, processed using Sea-Bird Scientific SBE Data Processing or Ruskin Software and the R package "oce", and saved as .CSV and .CNV files. The processed files have been transitionally migrated to the NOAA Fisheries Pacific Islands Fisheries Science Center (PIFSC) enterprise Oracle database in preparation for the implementation of adding OCC data entry into the existing Oracle APEX mission application. Data are then extracted from the Oracle database and distributed to the NOAA ocean data archive by region and year.

SBE-19plus CTD sensor:

Conductivity - measurement range: 0-9 S/m; accuracy: +/- 0.0005 S/m; stability: 0.0003 S/m per month; resolution: 0.00005 S/m;

Temperature - measurement range: -5-35 deg C; accuracy: +/-0.005 deg C; stability: 0.0002 deg C per month; resolution: 0.0001 deg C;

Pressure - measurement range: 0-600 m; accuracy: +/- 0.1%; stability: +/- 0.1%; resolution: 0.002%

RBR Concerto3 CTD sensor:

Conductivity - measurement range: 0-85 mS/cm; accuracy: +/- 0.003 mS/cm; stability: 0.010 mS/cm/year; resolution: 0.001 mS/cm

Pressure - measurement range: 0-500 m; accuracy: +/- 0.05% full scale; stability: +/- 0.05% full scale/year; resolution: 0.001% full scale

Temperature - measurement range: -5-35 deg C; accuracy: +/-0.002 deg C; stability: 0.002 deg C per month; resolution: 0.00005 deg C

Obviously erroneous data have been removed from the final dataset. Missing values are indicated with a blank.

The same methods of data collection are used each time a CTD cast is conducted. Conductivity, temperature, pressure, depth, salinity, and density are included in the observation dataset.

The data is quality controlled by NOAA PIFSC Ecosystem Sciences Division (ESD) personnel after the data is downloaded from the instruments, prior to and after the data are migrated to the PIFSC enterprise Oracle database, and once again when the data are submitted to the NOAA National Centers for Environmental Information.

The data is captured in several locations: files stored on the cruise server during the mission and the PIFSC network, and data are imported post-cruise into the PIFSC enterprise Oracle database. The cruise server is regularly backed up by the cruise data manager while at sea, and the PIFSC network is maintained and regularly backed up by PIFSC ITS.

Following a 1 minute soak, CTDs are usually deployed 5-10 feet above the reef at depths ranging from 0-30 m at permanent monitoring sites established by the NOAA Fisheries, Ecosystem Sciences Division.