On a few nights each August, just days after the full moon, Hanna Koch will be keeping watch at the Mote Marine Laboratory’s outpost on Florida’s Summerland Key, peering into tubs of water at the tentacle-ringed mouths of brilliant green, yellow, and purple corals. Close to midnight, staghorn, elkhorn, brain, and star corals will release tens of thousands of tiny glowing orbs into the water, and Koch will have her only chances of the year to create new generations of the species.
Each orb, or gamete bundle, holds millions of sperm and
