Identifying coral reef resilience potential in Tutuila, American Samoa based on NOAA coral reef monitoring data from 2010 to 2016

Declines in the health of coral reef ecosystems lead scientists to search for factors that support reef resilience: the ability of reefs to resist environmental stress and recover when they have been impacted, and to maintain key ecosystem functions throughout. Scientists have identified eleven measurable factors that affect the resilience of coral reefs. Reef resilience factors include characteristics of the coral assemblage, populations of fish that live on the reef, land-based influences, and sea surface temperature variability. NOAA Pacific Islands Fisheries Science Center (PIFSC) Ecosystem Sciences Division (ESD) used these factors to quantitatively assess the resilience potential of reefs around Tutuila and Aunu‘u Islands in American Samoa.

Locations of monitoring surveys conducted by ESD from 2010 to 2016 were used to designate study zones. The monitoring surveys provided data to evaluate biological/ecological resilience factors, and external data sources were used to inform physical and environmental factors not directly measured by ESD. Data for each metric was compiled, normalized, and averaged to produce a composite resilience score for each of zone. The primary resilience analysis includes all 11 metrics for 10 study zones around Tutuila and Aunu'u, excluding Taema Bank. The secondary resilience analysis includes the 8 metrics available for 11 study zones around Tutuila and Aunu'u, including Taema Bank.

The information provided with this analysis includes the individual datasets for the 11 metrics used in the analysis (data tables), the survey sites and study zones (data tables), and the resilience scores resulting from the analysis (data tables and maps).

Structural, ecological, and physical processes including, diversity, recruitment, herbivory, disease, and thermal tolerance have been identified as key elements contributing to reef resilience. This analysis, funded by the NOAA Coral Reef Conservation Program, integrates interdisciplinary data sets collected by NOAA Ecosystem Sciences Division and its partners to operationalize reef resilience in the U.S.-affiliated Pacific Islands. It is important to identify and understand these factors, so that management strategies can be tailored to maintaining or restoring coral communities to maximize their chances of survival in a changing climate. This analysis contributes to the local jurisdiction's capacity to meaningfully assess reef ecosystem condition in relation to a range of threats. A key aspect of the reef resilience framework is that it can empower local action to improve resilience of coral reefs because some drivers of resilience are heavily influenced by large-scale climatic forces, while others can be directly affected by local management.

Schumacher BD, Vargas-Ángel B and SF Heron. 2018. Identifying coral reef resilience potential in Tutuila, American Samoa based on NOAA coral reef monitoring data. NOAA Special Publication. NMFS-PIFSC-SP-18-03, 15 pp.

https://doi.org/10.7289/V5/SP-PIFSC-18-003

Reef resilience factors as described by McClanahan et al. (2012) include:

1. Pollution,

2. Sedimentation,

3. Herbivore biomass,

4. Macroalgae cover,

5. Coral diversity,

6. Coral recruitment,

7. Disease prevalence,

8. Bleaching resistance,

9. Physical impacts,

10. Fishing pressure, and

11. Sea surface temperature variability.

See download document "Tutuila Reef Resilience Files.docx" (data dictionary).

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.

Islands of Tutuila and Aunu'u, American Samoa

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Coral Reef Ecosystem Program (CREP) Data Sharing Recommendations, version 9.0 updated August 12, 2015:

CREP welcomes the opportunity to collaborate on research issues contributing to the scientific basis for better management of marine ecosystems. CREP 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 CREP principal investigators.

2) In all presentations, product releases, or publications using data generated by CREP, proper acknowledgement of both CREP 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, CREP requests that you share relevant information on complimentary data collections.

4) Those receiving data are strongly urged to inform the CREP 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 Program (CREP), 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 these data.

Example

Cite as: Schumacher, Brett; Ecosystem Sciences Division; Pacific Islands Fisheries Science Center (2018). Identifying coral reef resilience potential in Tutuila, American Samoa based on NOAA coral reef monitoring data. NOAA's National Centers for Environmental Information, https://www.fisheries.noaa.gov/inport/item/50521

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Data streams were compiled and analyzed by NOAA Ecosystem Sciences Division (ESD) researchers using MS Excel and Access 2010, Minitab, PRIMER version 6 with the Permanova+ add-on, and ArcMap 10.4.1.

The foundation of the analysis was in situ ecological survey data collected by NOAA Ecosystem Sciences Division under the National Coral Reef Monitoring Program (NCRMP). These surveys were conducted around Tutuila based on a stratified random sampling protocol.

Prior to conducting surveys, researchers are trained to identify and estimate/measure size of fish and corals along with other ecological metrics. Both classroom and field training and tests must be completed for all researchers (experienced and inexperienced alike) before each round of surveys begins. This training ensures that ecological surveys are conducted consistently by all researchers within survey efforts and also across periodic survey efforts.

See description of training process in "Accuracy" section.

This project integrated NOAA Ecosystem Sciences Division (ESD) survey data with data from other, external projects. Because external projects were implemented for purposes different from ESD surveys, the spatial extent of ESD surveys does not always align with other study zones. We endeavored to group sites and delineate study zones to align to the greatest degree possible.

Eleven metrics of reef resilience were identified in the McClanahan et al. 2012 paper. This project attempted to include all metrics in the analysis, but data to support three metrics (sedimenation, pollution and fishing pressure) were not available for Taema Bank. Therefore, a separate composite metric (Composite 8), was calculated for all zones so that resilience at Taema Bank could be evaluated.

Analysis is modeled after Maynard et al. 2012, "Coral reef resilience to climate change in Saipan, CNMI; field-based assessments and implications for vulnerability and future management." The current project utilized slightly different data streams in some cases (e.g. updated SST metrics), but the analysis followed the same overall procedures.

With some datasets, two different individuals generated summary statistics that were verified against each other. In other cases, the analysis was run two different ways or two different times and results were cross-checked. "Sanity checks" were also performed to evaluate if the results make sense and are logical.

NOAA IRC and NOAA Fisheries ITS resources and assets.

The principal analytical task of this project was to calculate eleven metrics of "reef resilience" as identified by McClanahan et al. (2012). These metrics account for various aspects of the coral reef ecosystem, and are derived from several data streams, as described in the process steps.