Smithsonian Tropical Research Institute


Project: Thermal performance and related stress responses to salinity and temperature extremes in Pocillopora spp. from the Panamanian Tropical Eastern Pacific

Project title

Thermal performance and related stress responses to salinity and temperature extremes in Pocillopora spp. from the Panamanian Tropical Eastern Pacific

Photo credit: Diana Lopez

Mentor name

Sean Connolly, STRI staff scientist
Co-mentor name and position: Diana López, postdoc fellow


Naos Marine Laboratory

Project summary and objectives

As climate change related stressors continue to pressure and harm coral reef ecosystems around the world, the mechanisms by which these systems resist or recover from perturbations remain poorly known. Across the Tropical Eastern Pacific (TEP), reef-building corals from the genus Pocillopora dominate the substratum, and until recently, had been misidentified as belonging to a single species. Primarily, two clades of Pocillopora dominate the seascape in regions with and without upwelling across Panama. Recent evidence shows Symbiodiniaceae assemblage can differ between these two Pocillopora clades, providing advantageous thermal tolerance to one of them. The mechanisms by which these corals cope with increased temperatures and other environmental stressors is still unknown. The aim of this project is to determine mechanisms by which the sensitivity of Pocillopora clades from upwelling and non-upwelling regions of the TEP within the Pacific coast of Panama varies in response to temperature and salinity extremes. Specifically, we will build thermal performance curves (TPC) using experimental assays that combine temperature gradients and extreme salinities to determine differences in performance (i.e., photosynthetic and respiration rates) between populations (i.e., upwelling vs. non-upwelling) and Pocillopora clades. In addition, we will use physiological techniques to determine thermal and salinity stress responses from experimental assays. Upon interest and expertise of the applicant, we may instead evaluate possible shifts in the coral microbiome in response to thermal and salinity stress.

Mentorship goals

The intern will work closely with a large and diverse group of scientists at all career stages. There would be opportunities for working in different settings (i.e., laboratory, field, outdoor experimental system) and to learn laboratory techniques to quantify coral physiological parameters.

Desired Background

The intern will work ~40 hours per week and would be expected to work on weekends for field expeditions when needed. The product would be a poster presentation at the intern symposium if timing is appropriate and the possibility of co-authorship in future peer reviewed publications.

List of suggested readings

Epstein HE, Smith HA, Cantin NE, Mocellin VJL, Torda G, van Oppen MJH. 2019 Temporal Variation in the Microbiome of Acropora Coral Species Does Not Reflect Seasonality. Front Microbiol 10. (doi:10.3389/fmicb.2019.01775)

Marangoni LF de B, Rottier C, Ferrier-Pagès C. 2021 Symbiont regulation in Stylophora pistillata during cold stress: an acclimation mechanism against oxidative stress and severe bleaching. Journal of Experimental Biology 224. (doi:10.1242/jeb.235275)

Hoegh-Guldbergl O, Smith GJ. 1989 The effect of sudden changes in temperature, light and salinity on the population density and export of zooxanthellae from the reef corals Stylophora pistillata Exper and Seriatopora hystrix Dana. Genetics and Ceff Biology 129, 279–303.

Dias M, Madeira C, Jogee N, Ferreira A, Gouveia R, Cabral H, Diniz M, Vinagre C. 2019 Oxidative stress on scleractinian coral fragments following exposure to high temperature and low salinity. Ecol Indic 107, 105586. (doi:10.1016/j.ecolind.2019.105586)

Till Röthig, T. Röthig, Michael A. Ochsenkühn, M. A. Ochsenkühn, Anna Roik, A. Roik, Riaan Merwe, R. Merwe, & Christian R. Voolstra, C. R. Voolstra. (0000). Long‐term salinity tolerance is accompanied by major restructuring of the coral bacterial microbiome. Molecular ecology, 25, 1308-1323. doi: 10.1111/mec.13567

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