Every couple of weeks, postdoctoral researcher Yosuke Yamada grabs a bucket and makes the short drive from his lab at Okinawa Institute of Science and Technology to one of the nearby ports on the southerly Japanese island of the same name. He passes Okinawa’s iconic beaches, where snorkelers visit clownfish and coral reefs, and continues to the fishing wharfs. After Yamada scoops a bucketful of water from between the boats, he heads back to his lab to study components of the island’s ecosystem that are so small they must be observed using a microscope: bacteria, viruses, algae, and fungi — the ocean’s microbes.