In a windowless laboratory in downtown Baltimore, some tiny, translucent fish larvae are swimming about in glass-walled tanks.
They are infant bluefin tuna. Scientists in this laboratory are trying to grasp what they call the holy grail of aquaculture: raising this powerful fish, so prized by sushi lovers, entirely in captivity. But the effort is fraught with challenges.
When I visited, I couldn't see the larvae at first. They look incredibly fragile and helpless, just drifting in the tanks' water currents. But they're already gobbling up microscopic marine animals, which in turn are living on algae.
"It's amazing. We cannot stop looking at them! We are here around the clock and we are looking at them, because it is so beautiful," says Yonathan Zohar, the scientist in charge of this project.