Metabolic Modeling
Metabolism is the sum of reactions happening within an organism's cells that provide energy for vital processes. The rate at which organisms take up, transform, and expend energy and materials has been called the most fundamental biological rate (Brown et al. 2004). Using laboratory based metabolic measurements, Harmony has constructed models to understand the influence of environmental perturbations, such as temperature and light, on the energetic balance within organisms. These models can be used to identify the thresholds of organisms, enabling prediction of persistence in our changing climate.
Coral bleaching studies often examine thermal stress as a function of a set temperature, but bleaching risk is traditionally quantified as a dose response function (i.e., in degree heating weeks). Dr. Martell has bridged this gap. She demonstrated that looking at thermal stress as a dose response, instead of just a set temperature value, can reveal exciting differences in organismal physiology. She is interested in examining thermal stress in a variety of marine invertebrates, including corals and crustaceans.
Temperature as a Dose Response
Current methods to predict mass coral bleaching utilize a measure of accumulated heat stress, but are not tied to any physiological mechanisms. As an ocean leaders postdoctoral fellow, Dr. Martell has developed a metabolic model of coral bleaching and is testing it on bleaching reports from the entire Caribbean from 2003-2017. Her model was built using previous knowledge of the relation of both temperature and light to coral metabolism and further developed in the Climate and Coastal Ecosystems Laboratory at UBC. She aims to tie a mechanism to mass coral bleaching bridging the gap from the physiology of the individual organism to responses seen at the ecosystem and ocean basin scales. She is also interested in quantifying the energetic reserves of corals at the colony scale as a means to gauge the timing of ecosystem persistence in the Anthropocene.
