Structure from Motion (SfM) Coral (Adult and Juvenile) Annotations derived from Stratified Random Site (StRS) Imagery across the US Pacific from 2019 to 2023 for methods compari...

Coral adult and juvenile coral colony demographic data described in this dataset are derived from the GIS analysis of benthic photomosaic imagery. The source imagery was collected using a Structure from Motion (SfM) approach during in-water surveys conducted by divers, and is documented separately here: https://www.fisheries.noaa.gov/inport/item/63095. The data were collected as part of the NOAA Pacific Islands Fisheries Science Center (PIFSC) and Ecosystem Sciences Division (ESD; formerly the Coral Reef Ecosystem Division) led National Coral Reef Monitoring Program (NCRMP) missions around the US Pacific from 2019 for method comparison. Refer to Lineage and URLs for links to publication.

The SfM surveys are part of the Rapid Ecological Assessment (REA) surveys for corals and fish conducted during ESD-led NCRMP missions. Surveys were conducted at sites randomly stratified across sub-island sectors and three depth strata (shallow: 0-6m, mid: 6-18m and deep: >18m). These sites represent a broad range of depths (1-25 m), habitat types (aggregate reef, patch reef, pavement, rock and boulder and rubble), coral cover, and diving conditions. Allocation of sampling effort was proportional to strata area and variance in coral density. The StRS design effectively reduces estimate variance through stratification using environmental covariates and by sampling more sites rather than sampling more transects at a site. Therefore, site-level estimates and site to site comparisons should be used with caution.

During each survey, an 18m transect line was deployed along the isobath and photographed using underwater cameras while swimming in a back and forth swim pattern for later processing using an SfM approach. At depths of 1-20 m, SfM surveys were conducted over a 3 x 20m area and at depths > 20m, a 3 x 13m area was surveyed, both with the transect running down the middle of the survey area. The photographs were processed using Agisoft Metashape software to generate orthomosaic images that were analyzed in ArcGIS for juvenile and adult coral colony demographic metrics. Data was collected for each site within four 2.5m2 segments, each 1m wide, along the transect (at 0-2.5m, 5-7.5m, 10-12.5m, and 15-17.5m). At deeper sites where a 3 x 13m area was surveyed, only the first three segments were analyzed in ArcGIS. For each adult coral colony (> 5cm in diameter), maximum diameter, ID (to lowest taxonomic level), and estimated percent old mortality were recorded. Bleaching extent (% of living tissue with reduced pigmentation) and severity were also recorded. Juvenile coral colonies (0.7 to 5cm maximum diameter) were recorded within the first 1 m2 of the first 3 segments. For juvenile colonies, only ID and maximum diameter were recorded.

The 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 Coral Reef Conservation Coral Reef 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. The purpose of the Structure from Motion (SfM) surveys throughout the US Pacific is to efficiently and effectively collect coral demographic data. SfM-derived data collection occurred along the same transects as in situ diver coral demographic surveys as a means to compare the use of SfM as a tool for quantifying coral demographic metrics in comparison to traditional visual in situ assessments.

Winston M, Couch C, Ferguson M, Huntington B, Swanson D, Vargas-Angel B. 2019. Ecosystem Sciences Division Standard Operating Procedures: Data Collection for Rapid Ecological Assessment Benthic Surveys, 2018 Update. NOAA Tech. Memo. NOAA-TM-NMFS-PIFSC-92, 66 p. doi:10.25923/w1k2-0y84

Suka R, Asbury M, Couch C, Gray A, Winston M, Oliver T. 2019. Processing Photomosaic Imagery of Coral Reefs Using Structure-from-Motion Standard Operating Procedures. U.S. Dept. of Commerce, NOAA Technical Memorandum NOAA-TM-NMFS-PIFSC-93, 54 p. doi:10.25923/h2q8-jv47

Couch CS, Oliver, TA, Suka R, Lamirand M, Asbury M, Amir C, Vargas-Angel B, Winston M, Huntington B, Lichowski F, Halperin A, Gray A, Garriques J, & Samson J. 2021. Comparing coral colony surveys from in-water observations and structure-from-motion imagery shows low methodological bias. Frontiers in Marine Science, 8. https://doi.org/10.3389/fmars.2021.647943

Charendoff J.A., Couch C, Oliver T, Lamirand M, Amir C, Basden I, Torres-Pulliza D, Asbury M, Winston M, Huntington B, Lichowski F, Osborn N, Ehrenberg J, Garriques J, Samson J. 2023. Comparing coral demographic surveys from in situ observations and structure-from-motion photogrammetry on high diversity reefs shows low methodological bias but highlights persistent areas of concern. U.S. Dept. of Commerce, NOAA Technical Memorandum NMFS-PIFSC-153,52 52 p. doi:10.25923/8r7f-t404

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 CRCP and supported by NOAA Fisheries, NOAA National Centers for Coastal Ocean Science (NCCOS), and many other partners. The PIFSC Ecosystem Sciences Division (ESD) at NOAA Fisheries is leading biological monitoring in the U.S. Pacific Islands Region.

The biological component of NCRMP in the Pacific provides a triennial ecological characterization at a broad spatial scale of general reef condition for reef fishes, corals and benthic habitat (i.e., fish species composition/density/size, benthic cover, and coral density/size/condition). Innovative analysis techniques are then 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.

As more imagery is collected and datasets are generated, we will continue to update this record.

Dataset includes metadata for each Structure from Motion (SfM) survey site (site information, survey date and location); site characteristics (depth, reef type, habitat); individual adult and juvenile coral observations identified to the lowest taxonomic level possible (usually species) including morphology, empirical size measurement, and all other recorded colony attributes including partial mortality and condition.

SfM Derived Juvenile Coral Annotations Data Dictionary

https://www.fisheries.noaa.gov/inport/item/63244

SfM Derived Adult Coral Annotations Data Dictionary

https://www.fisheries.noaa.gov/inport/item/63239

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.

U.S. Pacific Island Areas

Not applicable

Not applicable

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.

None

Please cite NOAA Fisheries, Ecosystem Science Division (ESD) when using the data.

Example:

Pacific Islands Fisheries Science Center, 2023: National Coral Reef Monitoring Program: Structure from Motion (SfM) Coral (Adult and Juvenile) Annotations derived from Stratified Random Site (StRS) Imagery across the US Pacific since 2019, https://www.fisheries.noaa.gov/inport/item/63097.

None

None

A GPS unit is used to record the location of each Structure from Motion (SfM) survey site. In 2019, a Canon SL2 DSLR digital camera in an Ikelite underwater housing was used to take photographs of each site. Coded markers 0.25-0.50 m long were used underwater to provide a scale for the mosaic imagery. Mosaic images were created and scaled using Agisoft Metashape (version 1.2.5 build 2735). Models were further scaled using the custom software Viscore. Sampling boundaries and coral demographic measurements were created in ArcMap (version 10.6.1). All statistics were performed in R (Version 3.6.1).

Starting in 2022, a Canon SL2 or SL3 DSLR camera in an ikelite housing was used to take photographs of each site. Coded markers 0.25 m long were used underwater to provide scale and depth information for each mosaic. Orthomosaic images were created using Agisoft Metashape (version 1.8.0 or later). Viscore was used for accessing raw imagery. Sampling boundaries and coral demographic measurements were created in ArcGIS Pro (version 2.8.0 or later). All statistics were performed in R (Version 4.1.2 or later).

The data set derived from the imagery is only as good as the images themselves; Images with poor resolution, poor lighting, extraneous objects (fins, etc), or blur were excluded from analysis.

Handheld GPS units were used to locate random sites and mark site locations.

Prior to conducting surveys, the SfM image collector was trained to swim in a back-and-forth pattern to collect imagery with 60-80% overlap. Both classroom and field training were completed before any surveys were conducted. This training ensures that all SfM image collection was conducted consistently during the mission.

Coral demographic data was extracted by SfM image annotators that had been trained, underwent a series of calibration efforts and testing on coral taxon identification testing, morphology, and condition assessment. All annotators met a set of minimum standards for coral demographic data collection.

The average Ground Sample Distance (GSD, resolution/pixel) for the produced 3D Structure from Motion models was 0.21 cm/pix, allowing confident identification of coral species from the resulting high-resolution 2D orthomosaics.

Only sites from shallow water (0 to 30 meter depth range) hard-bottom habitats were annotated. At deep sites, bottom time is limited and therefore survey area is reduced from 3 x 20 m to 3 x 13 m. Therefore, shallower sites, 4 2.5 m2 segments were annotated and for deeper sites (>30 m) 3 2.5m2 segments were annotated along the central transect line. Within each 2.5 m2 segment, only 1m2 of the segment was sampled for juvenile demographic metrics and for all sites, regardless of depth, only the first three segments along the transect line were annotated.

Main Hawaiian Islands 2019: SfM imagery was collected at all benthic REA survey sites but only at a subset of the Fish REA survey sites (145 SfM collections out of 300 sites total). Of the 145 sites where SfM imagery was collected, 104 sites were analyzed for juvenile and adult coral demographics via SfM.

Marianas Archipelago 2022: SfM imagery was collected at a subset of benthic and Fish REA survey sites (303 SfM collections out of 480 sites total). Of the 303 sites where SfM imagery was collected, 102 sites were analyzed for juvenile and adult coral demographics via SfM.

American Samoa/Pacific Remote Island Areas 2023: SfM imagery was collected at a subset of benthic and Fish REA survey sites (178 SfM collections out of 374 sites total). Of the 178 sites where SfM imagery was collected, 75 sites were analyzed for juvenile and adult coral demographics via SfM.

The same method of annotation was used for all SfM imagery.

Prior to generating the 3D dense point clouds and 2D orthomosaics , the JPEG imagery was evaluated for image quality and images deemed unsatisfactory (e.g. overexposed, images of blue water or images of divers, or images not taken perpendicular to the reef) were removed from the image set. During annotation in ArcGIS, the original JPEG imagery was viewed alongside the orthomosaic using the Viscore Image View feature to see fine scale colony details, observe colonies from multiple angles and locate colonies not visible in the orthomosaic. Annotations created in ArcGIS were quality controlled using a multi-stage process. Data were first quality controlled in R with specific queries to identify and correct data entry errors (e.g. misspelled species names, missing segments, data in incorrect columns, partial mortality >100%). Then data were summarized to the segment-level by annotator to identify potential issues (e.g. anomalously high or low mean values for specific metrics relative to other annotators). If issues were identified for a given annotator, that annotator reviewed and corrected each site if they did find errors. The third stage involved annotators reviewing a subset (10% of the annotated segments) of randomly selected segments (stratified by annotator) that they did not originally annotate and recording errors (e.g. species misidentification, missing or incorrect conditions, and missing colonies) to establish individual annotator error rates for each metric. If an annotator had greater than 10% error rate for a given metric all of that annotator's sites were reviewed and corrected for the metric in question by a different annotator.

NOAA IRC and NOAA Fisheries ITS resources and assets.

The benthic SfM survey methodology, employed by the NOAA Ecosystem Sciences Division (ESD), began in 2019. Benthic imagery is collected at stratified random sites and generated into orthomosaic images using Agisoft Metashape software. Orthomosaics are imported into ArcGIS for annotation. Annotation of SfM belt orthomosaics is modelled after in situ diver adult and juvenile coral belt surveys employed by the PIFSC Ecosystem Sciences Division and includes coral species identification, maximum diameter measurement, partial mortality estimates, and disease and condition identification.