Document Type
Abstract
Publication Date
2025
DOI
10.5343/bms.2024.0122
Publication Title
Bulletin of Marine Science
Volume
101
Issue
1
Pages
520
Conference Name
APCRS 5th Asia-Pacific Coral Reef Symposium, June 19-23, 2025, Singapore
Abstract
We analyzed the thermal tolerances of multiple coral species from an upper mesophotic (38–40m) and a shallow reef (5–10m) with our portable Coral Bleaching Automated Stress System (CBASS). Depth generalist Montipora grisea (deep and shallow) and depth specialists Pachyseris speciosa and Leptoseris sp. (deep only) were assayed from Leone, located on the western coast of Tutuila in American Samoa. Fragments from 10 genotypes of each species were exposed to a 17-hour thermal stress assay reaching four maximum temperatures ranging from 30–38°C under in situ light conditions (150 μmol photons m−² s−¹ under a Lee Filters “deep blue” light filter for mesophotic collections and 600 μmol photons m−² s−¹ for shallow collections). The temperature required to elicit a 50% reduction in dark adapted photochemical efficiency (Fv/Fm) was determined for each collection at the end of the thermal challenge (termed the Effective Dose 50 [ED50]). ED50s ranged from 36.4°C for the shallow Montipora grisea to 37.4°C for the deep Pachyseris speciosa, with a value of 36.5°C for the Leptoseris sp. There were no differences between the ED50’s measured for the deep (38–40m) vs. shallow (5–10m) M. grisea (36.5 vs. 36.4°C respectively), while the the ED50 for the deep P. speciosa was the highest. In situ temperature profiles for an adjacent 40m site showed high daily variability, which when coupled with the high ED50s suggests these populations host high levels of thermal tolerance.
Rights
© 2025 The Authors.
This article is open access under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0) License.
Original Publication Citation
Barshis, D., J. , Radice, V. Z., Parker, K., E. , & Evensen, N., R. (2025). Thermal tolerance limits of mesophotic corals in American Samoa. Bulletin of Marine Science, 101(1), 520. https://doi.org/10.5343/bms.2024.0122
Repository Citation
Barshis, Daniel; Radice, Veronica Z.; Parker, Katherine E.; and Evensen, Nicholas, "Thermal Tolerance Limits of Mesophotic Corals in American Samoa" (2025). Biological Sciences Faculty Publications. 652.
https://digitalcommons.odu.edu/biology_fac_pubs/652
ORCID
0000-0003-1510-8375 (Barshis), 0000-0002-4867-0164 (Radice), 0000-0003-3318-5593 (Evensen)