An average teaspoon of ocean water contains five million bacteria and fifty million viruses -- and yet we are just starting to discover how these "invisible engineers" control our ocean's chemistry. At TEDxMonterey, Melissa Garren sheds light on marine microbes that provide half the oxygen we breathe, maintain underwater ecosystems, and demonstrate surprising hunting skills. (Apologies for the small audio glitches in this video.)

Melissa Garren: The sea we've hardly seen

The sea we've hardly seen

Unveiling a tiny predator, a pathogen 'sniffs out' coral hosts, challenging our perceptions of microbial behavior in the ocean.

Microfluidic technology offers a glimpse at marine pathogens in action, setting the stage for combating coral reef diseases.

Five million bacteria in a teaspoon of seawater demonstrate marine microbes' vast role in ocean ecology and human health.