What do we survey
We collect benthic data of shallow coral reef ecosystems (up to 100 ft). This means identifying, counting, and sizing different organisms on the seafloor. We conduct coral demography surveys (coral composition & condition of adults and juveniles), as well as benthic cover surveys (cover of algae, CCA, hard coral, and other taxa). Read more on benthic cover in the NCRMP Data Viz Tool documentation.
How do we survey
As of 2023, we mainly use image-based surveys to collect benthic observations. Divers collect both photogrammetry models, stitching together thousands of images of a site, as well as photoquadrat imagery, relying on “unstitched” single images of a site. Using photogrammetry we can build 3D models of the coral reef and extract data, including coral demographic data (measured by divers in situ before 2024). The photoquadrat imagery is annotated with the AI tool CoralNet to provide estimates of benthic cover. We conduct surveys at both fixed and random sites; random sites allow us to provide geographically comprehensive estimates of data for an island or region, whereas fixed sites allow us to compare changes in the benthos over time at the same site, such as growth of specific coral colonies. We utilize machine-learning and also develop CoralNet Classifiers such as the semi-automated CoralNet Bleaching Classifier.
What do we measure
Our benthic cover raw data includes CoralNet point annotations, produced with the identification of benthic taxa under random points on photoquadrat imagery. The coral demographic data includes identification, counts, and sizes of juvenile and adult hard coral colonies, with conditions for adult hard corals (disease, bleaching, etc.). For example, in this photo, a diver is noting the stark white patch on the coral colony left from predation by crown-of-thorns seastars.
Training materials
Photogrammetry training and other community resources are available on LAI-NETWORK. To correctly identify coral species as well as their condition, such as causes of predation, our coral experts undergo thorough training. To mitigate diver biases, we routinely run and analyze our data for potential diver biases and have regular discussions to normalize our data and surveys. Please contact us for access to more training materials.
Why do we survey
By revisiting these regions since 2000, and with a stable, stratified random survey design since 2013, we can monitor and see how coral reef ecosystems are changing over time such as higher or lower coral cover, or coral recruitment or loss. We produce technical memoranda for policy makers that provide a summary of the status of coral reefs and inform management decisions. We can also integrate our benthic data with our fish and oceanographic data to investigate patterns in ecosystem shifts.
GitHub Repository
Currently we are working on making our scripts, such as one to summarize CoralNet data, public. Please contact us if you would like access.
Access Data
- Under 'Products' you can visualize and access our data using the NCRMP Visualization tool.
- Go to 'Methods' to see access for specific datasets.
- For raw data, our data is organized in NCEI collections and also described in our NCRMP InPort metadata catalog, organized by region.
- Access SfM imagery with NODD Google Cloud bucket, or make a request through the OER Portal.
Contact
- Principal Investigator: Thomas Oliver (thomas.oliver@noaa.gov)
- Data Services Team: nmfs.pic.credinfo@noaa.gov