Diver-Based Structure-from-Motion Imagery From Coral Reef Restoration Surveys in the Lower Florida Keys: July 2022 and July 2023

During the summers of 2022 and 2023, U.S. Geological Survey (USGS) researchers conducted underwater photographic surveys aimed at quantifying the impact that past coral restoration by Mote Marine Laboratory had on the reef-accretion process. A total of 39,840 non-georeferenced diver-based images were collected. The surveys were conducted along paired transects (approximately 10x2 meter [m] area) representing restored and non-restored areas of eight offshore reefs and three patch-reef sites in the Lower Florida Keys. Images at all sites, except for Summerland Ledges, were collected by divers using a downward facing Canon® PowerShot S120 camera in an underwater housing set to collect RAW images in continuous shoot mode. Summerland Ledges is an experimental restoration site consisting of two 10x10 m restored plots and one 10x10 m control plot. The two restored plots at Summerland Ledges were surveyed 2 m from the reef base using a dual Nikon® D7000 digital single-lens (DSLR) camera system and the control plot was surveyed using a Canon® EOS R at the surface. The number of transects and images varied per site depending on the availability of restored or control reef. All images were collected 1-2 m from the reef base using a double-lawnmower swim pattern ensuring 70-80% forward and lateral overlap between images. Images were used to generate structure-from-motion (SfM) products (point clouds, orthomosaics, and digital surface models), which were used to quantify percent cover of corals and other benthos and topographic complexity. The SfM products and census data are published in an accompanying data release by Toth and others (2025a). The percent cover and census-survey data were used in an associated study (Toth and others, 2025b) to quantify differences in carbonate budgets (gross carbonate production, bioerosion, and reef-accretion potential) between restored and non-restored areas of each reef.

Toth, L.T., Johnson, S.A., Lyons, E.O., Jenkins, C.M., Stathakopoulos, A., Bloomer, S.K., Mallon, J., and Combs, I., 2025a, Carbonate budgets, structure-from-motion products, and topographic complexity measurements from restored and non-restored areas of coral reefs in the Lower Florida Keys: U.S. Geological Survey data release, https://doi.org/10.5066/P13HMEON.

Toth, L.T., Johnson, S.A., Lyons, E.O., Spadaro, J., Stathakopoulos, A., Bloomer, S.K., Mallon, J., Jenkins, C.M., Williams, S.D., Combs, I., Craig, Z., and Muller, E., 2025b, Coral restoration can drive rapid increases in reef-accretion potential: Scientific Reports, https://doi.org/10.1038/s41598-025-04818-3.