Nighttime coral spawns are fascinating for recreational divers, but for Mary Hagedorn, they signal that it’s time to go to work. She holds a Ph.D. in marine biology from Scripps Institution of Oceanography and is currently based in Oahu, Hawaii, where she serves as the driving force behind a coral cryo-bank by collecting and freezing sperm and other cells for the future.

Q: Tell me about your bank. When would we use it?

A: Let’s imagine we lost a large percentage of coral from Kaneohe Bay and imagine we had a comprehensive bank of coral samples, which I’m working toward. We could rediversify the coral species in the bay by thawing the sperm samples and using them to fertilize eggs from the remaining coral. This is what was done for the black-footed ferret.

Q: A ferret?

A: It’s a very analogous situation. Blackfooted ferrets eat prairie dogs. Farmers hated the prairie dogs, so they poisoned all of them in the 1940s, making blackfooted ferrets extinct in the 1970s. Then one was found, and then 20, and brought into captivity. Scientists did the most sophisticated dating game you can imagine. Today, 3,000 black-footed ferrets roam the plains. The founders are still contributing to that population.

Q: Why can’t you start replacing lost corals now?

A: I don’t work my magic unless someone asks, and that’s the problem.

Q: Why is no one asking?

So many reefs look like a bomb went off. They’re not diverse, and they’re not beautiful.

A: We deny what’s in front of us. We have baseline shift. So many reefs look like a bomb went off. They’re not diverse, and they’re not beautiful. If we don’t have that sense of what pristine is, then we are not going to be upset when we dive and see algae. We think that’s a coral reef, and it’s not.

Q: How many species have you collected to date?

A: In Hawaii, we’ve collected 12 species. That sounds small compared to the 800 out there, but for me, it’s perhaps more important that we’re training the next generation to collect.