In the cover of darkness we swam in anticipation. The full moon shone only a day ago and already we were preparing for our annual spawning event. As the clock struck nine, we dropped down onto our nursery prepared to repeat our arduous task underwater. As I first inspected each nursery structure, I noticed a steady current blowing toward the South. Gentle, but steady, it carried little creatures that reflected in the light of our tiny flashlights. As I returned to the first structure I had inspected, I watched the other divers following my lead and inspecting each other structure. We might be here for two hours and any activity was welcome. But then I saw a familiar sight! The perfect, white round shape of a gamete.
The coral was spawning!
It lasted for around twenty minutes as a small section of one tree released thousands of tiny gamete packets. These delicate bubbles with both sperm and egg inside would possibly find other gametes and fertilize that very night! We had been underwater for mere moments and already rewarded with success! But it seemed that the few areas releasing were simply overstimulated and not part of a greater spawning event.
So we waited……late into the evening with no further spawning to show. I was still thrilled to be among the first in the region to see spawning and on a substantial scale! Facebook groups lit up and reports of uneventful dives drifted in overnight from around the Caribbean.
On our second night, we again waited in darkness but no further spawn activity occurred. We had hoped that the higher water temperatures this year might stimulate an early spawning, but the corals knew to hold to their day three spawn.
On the 18th, we rushed out and found that the current was still pushing South. One tree went into a full release of Gametes and swarms of white dots floated across the nearby reefs. In thirty minutes it was over, and secure that our corals were healthy and viable, we returned to celebrate. Our goal was met. These corals spawned. All of our planning and expectations hinged on this critical aspect.
Our interest is now to see what increase in this new direction we might see from our coral spawning. 2017 and 2018 both sent the gametes floating Northward and our surveys show an increase from roughly 3-7 corals in a 500m range up to an astounding 150-200 (ish) in the same area. Counting became confusing at one point where it is hard to define the edge of one coral versus the start of another. Our intention is to work toward photographic surveying methods to determine overall coral cover as opposed to jsut a direct counting of corals from our target species.
In two years we have already outpaced our expectations for our five year plan.
PS: if anyone has access to such technology and equipment, we would be very interested to speak with you about how to arrange a series of annual survey reports to describe how our treatment areas are changing.