Guam Long-term Coral Reef Monitoring Program Macroinvertebrate Belt Transects since 2010

The Government of Guam's Comprehensive Long-term Monitoring at Permanent Sites in Guam project, also known as the Guam Long-term Coral Reef Monitoring Program (GLTMP), is a NOAA-funded project currently coordinated through the University of Guam Marine Laboratory. The program involves the regular, intensive collection of data for a suite of coral reef ecosystem health parameters at high priority reef areas (HPRAs) around Guam, as well as critical support for coral bleaching response and other activities carried out by the multi-partner Guam Coral Reef Response Team. The program currently utilizes a split-panel sampling approach, whereby a mix of permanent and non-permanent sampling stations (one sampling station = one transect) are visited within each HPRA. The HPRAs were selected by an advisory body comprised of reef managers, researchers, and technicians; these reef areas were not intended to serve as representatives of Guam's reefs more broadly. The locations of the sampling stations within each HPRA are generated randomly using GIS software. Various coral reef surveys are carried out on an annual basis along the seaward slope between 7 and 15 m depth in the Tumon Bay Marine Preserve and in East Agana Bay, while surveys are carried out biennially within the Piti Bomb Holes Marine Preserve, the Achang Reef Flat Marine Preserve, the eastern side of the Cocos Barrier Reef (Cocos-East), and Fouha Bay. Surveys were also carried at along reef margin (1-2 m) and slope (2-15 m) of Western Shoals, in Apra Harbor, in 2011. The surveys, which are currently conducted by University of Guam Marine Laboratory biologists, and which were supported by NOAA PIRO through 2019, currently include benthic photo transects, stationary point count fish surveys, macroinvertebrate belt transects, and chain-length rugosity surveys. The GLTMP has conducted surveys at the Tumon and East Agana HPRAs since 2010 and the Piti HPRA since 2012. Data collection for the Achang and Cocos-East HPRAs began in 2014 and at the Fouha Bay HPRA in 2015. Baseline data is available for the Western Shoals HPRA from 2011 but this site has not been re-visited since its establishment due to shifting management priorities.

Macroinvertebrates are culturally, economically, and ecologically important resources for the island of Guam. In recognition of the value and importance of this resource, macroinvertebrate surveys are a key component of the Guam Long-term Coral Reef Monitoring Program. Macroinvertebrate surveys have been conducted at high priority reef areas around Guam since August 2010. The monitoring team counts the number of most commercially and ecologically important macroinvertebrate species within a 4 m x 30 m belt transect (4 x 25 m prior to 2017) at all stations (except at the Western Shoals stations, where 4 m x 15 m belts are used). The longest dimension of Tridacna individuals is also recorded. Boring urchins (e.g., Echinometra and Echinostrephus) were dropped from the survey beginning in 2020. Observations of these urchins, as well as other invertebrates, such as large hermit crabs, smaller gastropods, anemones, and other invertebrates that were not consistently recorded during the study period were removed from the 2010-2020 dataset archived with NCEI in October 2023. These observations can be provided upon request. These monitoring data on macroinvertebrate communities provide results on macroinvertebrate density allow for exploration of community structure by functional group; and can be used to detect changes in macroinvertebrate communities over time.

IMPORTANT: The 2010-2019 macroinvertebrate observations dataset initially archived with NCEI did not include zero count records, which could result in erroneous density values when averaging count or density values. Zero count records were added to the dataset using a cast and melt operation in R, and the updated dataset was archived with NCEI in November 2023.

The stated goals of the Guam Long-term Coral Reef Monitoring Program (GLTMP) are to determine the status and trends of selected coral reef ecosystem indicators to inform resource managers' decision-making process, provide managers with early notice of abnormal conditions, provide data to better understand the dynamic nature of the island's coastal ecosystems, allow resource agencies to meet certain legal and Congressional mandates, and measure progress towards performance goals. Benthic cover data collected by the GLTMP at several High Priority Reef Areas around Guam provide documentation of the structure and condition of the benthic communities at these sites; data from multiple visits can be used in time series analyses to determine trends in key ecosystem parameters.

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The following FGDC sections are not currently supported in InPort, but were preserved and will be included in the FGDC export:

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Macroinvertebrate belt transect data have been collected along permanent and non-permanent sampling stations at multiple monitoring sites since 2010, including:

Tumon Bay: 2010 (8 perm, 7 non-perm); 2012 (12 perm, 9 non-perm); 2014 (12 perm, 4 non-perm); 2015 (12 perm, 10 non-perm); 2017 (12 perm, 2 non-perm); 2018 (12 perm, 0 non-perm); 2019 (12 perm, 7 non-perm); 2020 (12 perm, 10 non-perm); 2021 (12 perm, 10 non-perm); 2022 (12 perm, 10 non-perm)

East Agana Bay: 2010 (5 perm, 10 non-perm; missing data for 5 perm); 2012 (10 perm, 0 non-perm); 2014 (10 perm, 0 non-perm); 2015 (10 perm, 0 non-perm); 2017 (10 perm, 0 non-perm); 2018 (10 perm, 0 non-perm); 2019 (9 perm, 6 non-perm); 2020 (10 perm, 10 non-perm); 2021 (10 perm, 10 non-perm); 2022 (10 perm, 10 non-perm)

Western Shoals: 2011 (11 perm, 12 non-perm)

Piti Bay: 2012 (10 perm, 10 non-perm); 2014 (10 perm, 2 non-perm); 2017-2018 (8 perm, 0 non-perm); 2020 (10 perm, 10 non-perm); 2022 (10 perm, 10 non-perm)

Achang: 2014 (11 perm, 3 non-perm); 2018 (10 perm, 0 non-perm); 2021 (10 perm, 10 non-perm)

Cocos-East: 2014 (3 perm, 2 non-perm); 2018 (7 perm, 0 non-perm); 2021 (10 perm, 10 non-perm)

Fouha Bay: 2015 (13 perm); 2019 (13 perm); 2021 (13 perm)

Data entry and quality control are complete for data collected through 2022.

Raw survey data includes metadata for each survey (where, when, who, area); site characteristics (depth, reef type, habitat, exposure); individual macro-invertebrate observation counts identified to the lowest taxonomic level possible (usually species); and parameters needed to calculate 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. The Guam Coastal Management Program makes no warranty, expressed or implied, nor does the fact of distribution constitute such a warranty.

Tumon Bay

East Agana Bay

Western Shoals

Piti (Tepungan) Bay

Achang

Cocos-East

Fouha Bay

Not applicable

Not applicable

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

None

Please cite the Guam Coastal Management Program when using data collected prior to October 2013. Guam Coastal Management Program, Guam Bureau of Statistics and Plans, Government of Guam. Please cite the University of Guam Marine Laboratory when using data collected after (and including) October 2013.

Example citation:

For data collected from 2010 to 2012:

Guam Coastal Management Program (2019). Guam Long-term Coral Reef Monitoring Program Macroinvertebrate Belt Transects since 2010. NOAA's National Center for Environmental Information, https://www.fisheries.noaa.gov/inport/item/47782.

For data collected after 2012:

University of Guam Marine Laboratory (2019). Guam Long-term Coral Reef Monitoring Program Macroinvertebrate Belt Transects since 2010. NOAA's National Center for Environmental Information, https://www.fisheries.noaa.gov/inport/item/47782.

None

None

Observations recorded on data sheets are entered into a data management website that populations a Microsoft SQL Server administered by the University of Guam.

Observations at each site were made by divers who have been trained and met minimum standards in identifying species present at the survey locations. Species identification and counts were periodically checked for accuracy and consistency between divers, and little discrepancy was noted.

Effort is made to avoid inter-observer bias through consistent training of macroinvertebrate surveyors by the Program Coordinator and by reference to an established protocol document.

Improvement over time in observers' general level of skill with the survey method, and an evolving understanding of the taxa at the monitoring sites, should be taken into account when comparing data across time; however, minor improvements in skill are not expected to have a significant impact on data quality. Comparisons of data across sites or across years must take into account differences in environmental and biological aspects of each site. Comparisons for a give site across time should consider any changes to the site boundaries over time. Please refer to the Extents section of this metadata record to see how the Tumon site boundaries shifted after 2010.

Only hard-bottom habitats are surveyed. Surveys are conducted annually to biennially for the Tumon and East Agana sites, but are conducted on a less frequent basis at other sites. In addition, while all permanent sampling stations are generally surveyed each sampling period, surveys are not always conducted at the full set of non-permanent stations for each site during each sampling period.

Unfortunately, several macroinvertebrate data sheets were lost before data was entered into the data management system, resulting in the absence of data for several sampling stations in the Tumon and East Agana sites in 2010.

Below is a summary of the number of permanent and non-permanent sampling stations for which macroinvertebrate data is available each year for each site:

Tumon Bay: 2010 (8 perm, 7 non-perm; missing data for 2 perm and 3 non-perm); 2012 (12 perm, 9 non-perm); 2014 (12 perm, 4 non-perm); 2015 (12 perm, 10 non-perm); 2017 (12 perm, 2 non-perm); 2018 (12 perm, 0 non-perm); 2019 (12 perm, 0 non-perm); 2020 (12 perm, 10 non-perm); 2021 (12 perm, 10 non-perm); 2022 (12 perm, 10 non-perm)

East Agana Bay: 2010 (5 perm, 10 non-perm; missing data for 5 perm); 2012 (10 perm, 0 non-perm); 2014 (10 perm, 0 non-perm); 2015 (10 perm, 0 non-perm); 2017 (10 perm, 0 non-perm); 2018 (10 perm, 0 non-perm); 2019 (9 perm, 6 non-perm); 2020 (12 perm, 10 non-perm); 2021 (12 perm, 10 non-perm); 2022 (12 perm, 10 non-perm)

Western Shoals: 2011 (11 perm, 12 non-perm)

Piti Bay: 2012 (10 perm, 10 non-perm); 2014 (10 perm, 2 non-perm); 2017-2018 (8 perm, 0 non-perm); 2020 (10 perm, 10 non-perm); 2022 (10 perm, 10 non-perm)

Achang: 2014 (11 perm, 3 non-perm); 2018 (10 perm, 0 non-perm); 2021 (10 perm, 10 non-perm)

Cocos-East: 2014 (3 perm, 2 non-perm); 2018 (7 perm, 0 non-perm); 2021 (10 perm, 10 non-perm)

Fouha Bay: 2015 (13 perm); 2019 (13 perm); 2021 (13 perm)

Data entry and quality control are complete for data collected through 2022.

The same methods of data collection were used at each of the stations surveyed. Surveys were conducted by a team of scientists that met minimum qualifications and trained and calibrated together.

All observations entered into the database through the online data entry system are compared against observations recorded on the raw data sheet. Once all database records are verified the quality control process is marked as complete for all observations associated with a given station/sampling period. It should also be noted that the data management system employs hard and soft validation to minimize data entry errors.

University of Guam Marine Lab resources and assets

The Macroinvertebrate Survey methodology, employed by the Guam Long-term Coral Reef Monitoring Program since 2010