To investigate the interactions between microbial symbionts and benthic marine invertebrates like sponges and corals, we frequently couple manipulative experiments with stable isotope analysis. These methods allow us to address fundamental questions about these symbioses: 

  1. What is the nutritional (C, N, and even H) benefit of these interactions to the host?
  2. How and why do these interactions vary across host species and functional groups (reef-building corals, octocorals, sponges, and even jellyfish)?
  3. How does symbiont physiology change with the environment and, importantly, how does this impact the host?