Coral colonies off the Florida Keys seemed to be especially frisky this year.
The coral spawn this month exceeded the expectations of researchers and conservation groups, officials said.
Brain and star corals, and the protected elkhorn and staghorn coral colonies, exchange gametes (eggs and sperm) to reproduce during the full moons of August and September.
The white excretion, resembling an underwater snowstorm, enables the eggs and sperm to enter the water in massive quantities over large geographic areas, maximizing the chances of fertilization and overwhelming predators with more eggs and sperm than they can consume.
When egg and sperm unite, the newly formed larvae, called planula, ascend to the surface to float in the current. Within a matter of days or even weeks, the planula settles to the bottom to grow into a polyp and eventually form colonies.
What triggers this event remains unclear, though scientific observations indicate a strong connection between the coral spawn and seasonal lunar cycles, as well as multiple environmental cues such as water temperature, tidal and 24-hour light cycles.
This month was a particularly active coral spawn, according to coral conservation officials and coral researchers.
"This was a second good year," said Margaret Miller, a coral researcher with National Oceanic and Atmospheric Administration's Southeast Science Center in Miami. "Both of the acropora species (staghorn aned elkhorn corals) did well .... The larger boulder were a bit underwhelming. We are going to do more observations of them next month to see if they do better."
The Tavernier-based Coral Restoration Foundation saw large numbers of coral spawning at its elkhorn and staghorn coral nursery and coral outplanting sites off Key Largo, foundation founder Ken Nedimyer said.
"Last year was good, but this year was amazing," Nedimyer said. "We couldn't even handle it all. A few of the corals we planted on the reef have now spawned. It (outplanting of coral) has made a difference."
Another nursery outplanting site off Marathon was also active during this month's spawn, Florida Fish and Wildlife Marine Institute biologist Kerry Maxwell said. Four of the colonies planted off Marathon spawned, Maxwell said.
The Coral Restoration Foundation set up an elaborate system to capture thousands of eggs and sperm and gave them to Mote Marine Laboratory and other research agencies for scientific purposes, Nedimyer said.
"This year was a great year," Nedimyer said. "The weather was perfect."