Hi, Harmony Martell! Great to have you on ReefBites.
Harmony completed her Ph.D. at Old Dominion University studying thermal performance, stress memory, and metabolic modeling during the acclimation process of corals. Read more about Harmony’s research below!
Give an elevator pitch of what your research/project is about.
My dissertation research examined 3 themes:
(1) The potential for acclimatization in two massive coral species living in the variable nearshore tidepools on Ofu, American Samoa.
(2) The differences in coral physiology under acute versus gradual thermal exposure in the absence of acclimation.
(3) Whether pulsed priming confers any benefit to corals in a subsequent bleaching event and whether corals have evidence of a stress memory.
Why is this research/project important and timely?
There has been great attention paid to whether or not corals can cope with the changing climate, and while they possess acclamatory mechanisms, my work seems to indicate that acclimatization alone is insufficient to save corals in the Anthropocene.
What is the broader impact and implication of your findings?
Previous studies on Ofu Island, American Samoa have shown corals have the ability to acclimatize to more stressful thermal microhabitats. However, this work has largely focused on a few species, namely the branching coral Acropora hyacinthus. My work examined the acclamatory potential in two massive species, Goniastrea retiformis and Porites lobata, by moving corals from a site of moderate temperature variability to sites of low, medium and high temperature variability. There was no significant change in bleaching resistance before and 7 months after transplantation, but both species had reduced growth in the most stressful site.
My work on thermal performance and stress memory tells us exposure is everything; coral physiology in heat shock experiments don’t necessarily translate to physiological response with gradual warming or what should be expected in the environment. In addition, placing thermal stress in a dose-context to examine physiological responses can really help to identify fine-scale differences. Corals and their symbionts appear to have a cellular memory of stress, but it is ephemeral (short-lived) and while repeated stress could be potentially beneficial, it is also strongly dose dependent. The ‘Goldilocks’ nature of the previous exposure makes using stress memory difficult to employ as a tool for coral hardening.
How did you come to work in this field/project?
I was given the opportunity to conduct my fieldwork and my first chapter in Ofu, American Samoa; previous work done there set the stage for additional studies – the low human impacts in this remote location coupled with the natural variability in the nearshore backreef pools makes for some cool experiments! While taking an aquatic photosynthesis course in the first semester of my Ph.D., I fell in love with physiology. Being able to plop an organism in a respiration chamber and see an instant response is very gratifying to me, and you can learn some very cool things using fine-scale physiology. I learned to build respiration chambers, and redesign temperature controllers. My last chapter was the riskiest, as I had one shot to do the experiment (I crowdfunded the project). I designed the experiment to perform the greatest number of treatments I could manage, which wasn’t easy. I slept on the floor in the lab a few nights, so I would be sure nothing went wrong!
What is your top graduate school life hack or survival resource?
Write every single day. Do it before you start your day. Jump out of bed, and just write. Get your coffee if you must, but write. This is the only way I managed to finish my dissertation. Even if you get 3 words on the page—write.
Any additional information or comments you would like to share?
Reach out often to your colleagues, labmates, friends in the field and discuss ideas and talk about your research. It helps you hone your message and tell the story of your research.