Cauliflower Coral Spawn

As I prepared to enter the water at Honaunau on April 27, a local asked me if I had come to photograph the coral spawn. I had no idea such an event was expected and just told him I was there to see whatever there was to see. He replied that the spawning would start in 15 to 20 minutes.

I dropped below the surface and started exploring, appreciating some of the best visibility I had seen in some time. Sure enough, around 15 minutes into the dive smoky haze began to emerge from the cauliflower corals (Pocillopora meandrina).

All photos Copyright 2013 by Barry Fackler

My vision could not distinguish individual gametes like I had seen in some documentaries, but what started out as a light haze increased very rapidly.

Visibility quickly dropped from nearly 100' to about 6' in around five minutes. It actually got surprisingly darker and the reef fish, including non-plankton-feeders, became more active.

For a few minutes, I could no longer navigate as my only visual reference was the direction that sunlight was weakly filtering through the thickened water. This was a very new experience for me.

I imagined such a burst of microscopic activity might bring a giant filter-feeder or two onto the reef but that was not to be. After a short while the fog began to clear and I resumed my dive. After completing my dive and taking a one-hour surface interval, I returned for a second dive to find visibility almost back to normal.

After returning home, i searched the internet to find that Pocillopra meandrina spawns April/May at full moon and/or 2-3 days after at around 7:30 in the morning. So it was one of those rare occasions where I was at the right place at the right time!