Corals, writ small

Tropical reef-building corals are complex biological systems that depend upon a delicate balance of symbioses among intracellular dinoflagellates (zooxanthellae), bacteria, archaea, viruses, and the coral animal itself. We have used microfluidic experiments and video microscopy to tease apart the chemical and physical interactions underpinning coral health and disease processes at the microscale. For example, we found that coral-associated bacteria, including pathogens, show chemotactic responses toward coral-derived chemical cues, and that pathogen host-seeking behavior is enhanced by rising seawater temperatures. We also showed that reef corals generate complex ciliary flows along their surface, affecting mass transport to and from the coral, and in particular the export of oxygen from zooxanthellar photosynthesis.   For more information, please contact Vicente Fernandez (fernandez@ifu.baug.ethz.ch).