Where are you from, and what is your role in Extreme 2004?

I am currently working in Dr. Colleen Cavanaugh's lab at Harvard University as an NSF Microbial Biology Postdoctoral Fellow. On this cruise, I will be collecting vent endemic animals and substrate to study the ecology and evolution of symbioses between hydrothermal vent invertebrates and the bacteria hosted within their tissues.

What questions are you trying to answer and why?

The overarching goal of my research is to examine the influence that geography, physical oceanography, and host biology have on populations of symbiotic bacteria. Hydrothermal vent communities are patchily distributed along spreading ridges due to topographic features, deep ocean currents, and variations in vent fluid chemistry. Though associations between chemosynthetic bacteria and their invertebrate hosts provide the basis for macrofaunal production at deep-sea hydrothermal vents, almost nothing is known about the structure of symbiont populations and its impact on the ecology and evolution of symbioses at vents.

Vent endemic mussels in the genus Bathymodiolus provide an excellent model system for testing hypotheses of bacterial population structure because the mussels have a global distribution at deep-sea hydrothermal vents and the chemoautotrophic endosymbionts are most likely transmitted environmentally, and thus may disperse independently of their host. Endosymbionts of Bathymodiolus thermophilus on the East Pacific Rise are referred to as 'thioautotrophs' because of their ability to oxidize hydrogen sulfide for energy. For my study, I will perform genetic analyses on the mussels, their symbionts, and nearby sediment, to determine the degree of isolation among populations of symbiotic bacteria and attempt to infer the environmental and biological factors underlying their diversification.

Why is this research important? What are the benefits?

Resolving how populations of bacterial endosymbionts are structured has important implications for microbial biogeography, diversity, and the origin, evolution, and ecology of life at deep-sea hydrothermal vents. Broader implications of this research will include inferences of how deep ocean currents influence dispersal of organisms and the evolution of chemoautotrophic communities. Moreover, because hydrothermal vents serve as analogs to early Earth as well as extraterrestrial environments, results from my research will have implications for the origin of eukaryotic cell organelles and the ecology and evolution of microbes in extreme biomes.

What is your background, and what lured you into marine science/education?

I've spent most of my life on or near the ocean and so it is only natural that I should be enamored by the sea. While growing up in northern California, I enjoyed many weekends of camping with my family on the rugged Mendocino coastline and filling buckets with an assortment of creatures trapped by the outgoing tide. I was awed by the incredible diversity of animals inhabiting the tide pools and wondered what lurked in the deeper waters. So, for college, I went to UC San Diego, where among other things, I learned to SCUBA dive and surf. Within the kelp forests, I encountered animals that I'd never seen before — brilliant orange garibaldi, cryptic octopi, electric rays, curious seals, and shy lobsters. My enthusiasm in the diversity of sea creatures developed into a strong interest in how they interacted over ecological and evolutionary time scales. I went on to earn a master's degree at the University of Hawaii in coral reef fish ecology and a Ph.D. at the University of Colorado in comparative phylogeography. Now, I am applying my skills as a molecular ecologist to address questions concerning the evolution and ecology of symbioses in one of the most fascinating and unexplored regions of the world — the hydrothermal vents of the deep sea!