Table of Contents

• Coverage
• Dataset Description
  • Methods & Sampling
  • Data Processing Description
  • BCO-DMO Processing Description
  • Problem Description
• Data Files
• Supplemental Files
• Related Publications
• Related Datasets
• Parameters
• Instruments
• Project Information
• Funding

See the "Related Datasets" section for other closely related data that was also part of the study published in Brown et al., 2024.  

Dataset "Short-term heat stress assay Heron Island - physiological data" contains a supplemental file ed50.csv which contains Photochemical yield and color score data from the Heron Island short term heat assay which was used to determine effective dose 50 (ED50, thermal tolerance).  The Heron Island ED50 values are included in this thermal tolerance comparison dataset.

Three published studies using the standardized experimental approach (i.e., (Evensen et al. 2023)) were identified to compare coral thermal thresholds across reef systems and spatial scales: 1. Florida Reef Tract in the Caribbean (~300 km) (Cunning et al. 2021), 2. Coral Sea in eastern Australia (~860 km) (Marzonie et al. 2022), and 3. Red Sea (~900 km) (Evensen et al. 2022). Reported values of coral thermal tolerance (i.e., Fv/Fm ED50) were compiled by nursery/reef/site. To compare regional (Florida Reef Tract, Coral Sea, Red Sea) coral thermal tolerance with local (Heron Island), the range of coral thermal tolerance was calculated for each species by computing the difference between the site with the greatest thermal tolerance and the site with the lowest thermal tolerance. 

Organism Genera (Genus, Lifesciences Identifier [LSID]):
Pocillopora, urn:lsid:marinespecies.org:taxname:206938
Porites, urn:lsid:marinespecies.org:taxname:206485
Acropora, urn:lsid:marinespecies.org:taxname:205469
* see supplemental file species_list.csv for supplemental information and LSIDs for all species names in the data table for this dataset.

For more detailed information on analysis and results, please see: Brown, et al. (2024).

* submitted file "ed50 comparison across studies.csv" was imported into the BCO-DMO data system for this dataset. No changes were made to the table.
** Missing data values are displayed differently based on the file format you download.  They are blank in csv files, "NaN" in MatLab files, etc.

* Site list with site name, site code, lat, lon was provided by email and joined into the data tables for this dataset and related datasets. Site in this and related datasets was either the code or full name but changed to more explicit names (Site_Name, Site_Code).

NSF Award Abstract:
Coral reefs are incredibly diverse ecosystems that provide food, tourism revenue, and shoreline protection for coastal communities. The ability of coral reefs to continue providing these services to society is currently threatened by climate change, which has led to increasing ocean temperatures and acidity that can lead to the death of corals, the animals that build the reef framework upon which so many species depend. This project examines how temperature and acidification stress work together to influence the future health and survival of corals. The scientists are carrying out the project in Hawaii where they have found individual corals with different sensitivities to temperature stress that are living on reefs with different environmental pH conditions. This project improves understanding of how an individual coral's history influences its response to multiple stressors and helps identify the conditions that are most likely to support resilient coral communities. The project will generate extensive biological and physicochemical data that will be made freely available. Furthermore, this project supports the education and training of undergraduate and high school students and one postdoctoral researcher in marine science and coral reef ecology. Hands-on activities for high school students are being developed into a free online educational resource.

This project compares coral responses to acidification stress in populations experiencing distinct pH dynamics (high diel variability vs. low diel variability) and with distinct thermal tolerances (historically bleaching sensitive vs. tolerant) to learn about how coral responses to these two factors differ between coral species and within populations. Experiments focus on the two dominant reef builders found at these stable and variable pH reefs: Montipora capitata and Porites compressa. Individuals of each species exhibiting different thermal sensitivities (i.e., bleached vs. pigmented) were tagged during the 2015 global coral bleaching event. This system tests the hypotheses that 1) corals living on reefs with larger diel pH fluctuations have greater resilience to acidification stress, 2) coral resilience to acidification is a plastic trait that can be promoted via acclimatization, and 3) thermally sensitive corals have reduced capacity to cope with pH stress, which is exacerbated at elevated temperatures. Coral cells isolated from colonies from each environmental and bleaching history are exposed to acute pH stress and examined for their ability to recover intracellular pH in vivo using confocal microscopy, and the expression level of proteins predicted to be involved in this recovery (e.g., proton transporters) is examined via Western blot and immunolocalization. Corals from each pH history are exposed to stable and variable seawater pH in a controlled aquarium setting to determine the level of plasticity of acidification resilience and to test for pH acclimatization in this system. Finally, corals with different levels of thermal sensitivity are exposed to thermal stress and recovery, and their ability to regulate pH is examined over time. The results of these experiments help identify reef conditions that promote coral resilience to ocean acidification against the background of increasingly common thermal stress events, while advancing mechanistic understanding of coral physiology and symbiosis.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.