1. Monterey Bay Aquarium Research Institute, Moss Landing, CA 95039, USA.
2. Department of Ocean Sciences, University of California, Santa Cruz, CA 95064, USA.
3. Integrated Microbial Biodiversity Program, Canadian Institute for Advanced Research, Toronto, Ontario M5G 1Z8, Canada.
4. Department of Earth Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
5. Department of Microbiology, Oregon State University, Corvallis, OR 97331, USA.
6. Department of Botany, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada.