So your corals spawned, what now?

Every Summer our corals spawn one time and blanket nearby reefs with larval corals. Since our project began in 2016 we have seen our corals spawning every year. Of course, in 2016 the corals were so tiny that they were unable to contribute much to the nearby reef, but in 2017 and then again in 2018, the corals had grown to a reasonable size and the impact they had on our reefs is amazing.

In 2018 we recorded our corals spawning, but we also wanted to establish what population of ACER (Acropora Cervicornis) was present. On the majority of our surveys we found 3-7 every 500 meters. However when we approached our nursery sites at Divetech and Sunset House, we noticed a dramatic increase in corals. 42-43 corals were found ranging from the size of my hand to the size of a small bus. Something had changed in these two areas, and we believe it was our corals spawning in 2017.

Now our surveys in those areas are counting upward past 150 to possibly 200 corals with a overall coverage of reef that makes it hard to clearly define each coral head and what metric to use for counting overall colonies. A mosaic based photography survey aided by computers is likely to be our next option for useful data. As each existing coral ages, it develops sexually. As we view our corals spawning in 2021, we should also see those first generation of corals joining our nursery corals in spawning. As later years of spawned corals reach sexual maturity, we complete a critical cycle of reef health. A self sustaining cycle that feeds new coral back into the reef faster than it is depleted.

This cyclical process becomes ever more important when we also look forward in time and see one of our greatest new threats in all its unfurled fury. Rising water temperatures and storms will continue to make ever larger areas of the sea uninhabitable for our corals.

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It only takes one bad day to kill a coral. Water gets too hot for a day, or a storm rages too strong and suddenly there is no longer any coral surviving in an otherwise ideal habitat.

Twenty years ago, these rising temperatures were not an issue, but that changed and I fear for how much more change we must prepare ourselves for. Creating a sustainable reef that is replenishing its coral species at a stable rate is wonderful if nothing ever changes. But that is not the reality. Instead we must look for how to encourage those corals to migrate into ever safer waters during their annual spawning events. Our island is a pinnacle rising steep from the depths. Settlement of our corals in ever deeper water along the edge of the island might prove to be the only long term protection we can offer to our corals. In fifty or even one hundred years, it is very reasonable to believe that our reefs might look very different despite all of our efforts. However, live stony corals might only exist in a few pockets where we have carefully nurtured them into safety through our coral management program.

This is an extinction event. We created it and we have to live with it. I hope that my plan will allow some small sources of coral to escape this extinction in the Caribbean. We can save these amazing creatures and future generations can see the return of living reefs. But this will only happen if we face the reality of what has happened and prepare for the long term goal of survival for these amazing corals.

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