Water as Critical Nutrient

This theme investigates the physiological and ecological adaptions of terrestrial and marine organisms (mammals, reptiles, birds) that enable them to maintain water balance.

We often neglect to think of water as a crucial nutrient, especially in polar, desert, or marine habitats.

As a postdoctoral scientist at UNM, I am developing a novel method that can be used to quantify the proportional contribution of ingested versus metabolic water that contribute to the total body water pool of an organism. Tracing how free-ranging organisms interact with their environment to maintain water balance is a rarely explored topic due to methodological limitations, but some species rely heavily on metabolic water, a byproduct of aerobic oxidation produced in the mitochondria.

Building on recent work, we are developing a method based on high-precision measurements of all three stable isotopes of oxygen to quantify the contribution of metabolic water to the total body water pool of free-ranging organisms. First, we are applying this approach to construct longitudinal records of water balance at the individual level for a guild of northern Chihuahuan Desert rodents that live in a stochastic resource-limited environment.

I have also expanded this approach to native ectotherm communities in New Mexico and am collaborating on a project with collaborators in South America (Dr. Pablo Sabat, University of Chile) focused on a genera (Cinclodes) of unique songbirds that live in coastal habitats and consume varying amount of saltwater directly or via the ingestion of intertidal marine invertebrates.

Finally, I am also developing a laser-based method to make high-precision triple oxygen isotope measurements more accessible, which will facilitate the adoption of this method by ecophysiologists.