Measuring Realized Resilience: Transforming Large Area Imagery into Coral Demographic Models in the Face of Disturbance

While small-scale coral demographic models have long shown promise to inform coral management, the labor-intensive work required to measure colony vital rates in “mark-recapture” studies has kept these models focused on small target populations.

However, by leveraging the game-changing technology of fixed-site photomosaics, NOAA’s US National Coral Reef Monitoring Program and partners can now rapidly generate accurate measures of coral colony-level recruitment, growth, and mortality across thousands of colonies at tens to hundreds of sites per region. With this level of replication in colony-level vital rate measurement, we can produce statistically robust demographic models, which allow for accurate estimation and projection of population-level trends across whole regions and, through sensitivity analysis, allow management interventions to target the vital rate most likely to improve a coral population’s chance to avoid extirpation.

In this presentation, we will highlight our approach using Fixed Site Photomosaics, explore the 65 sites across the Hawaiian Archipelago in which we and our partners have collected imagery at between 2 and 7 time points, spanning 2013 - 2019, documenting 3 major bleaching events. We will report on the subset of sites for which we have generated spatially explicit vital rates and projection models, and we will highlight spatial inferences about colonies and populations from intra-site to regional scales.

Using Fixed-Site Photomosaics to generate spatially-explicit, colony-level vital rates has direct implications for guiding management from targeting interventions toward the most sensitive vital rates, to generating a spatially explicit “phenotype address book” for targeting restoration work and providing a foundation for phenotypically-driven explorations of the genomic bases of colony traits.