On June 23rd, 2021 fifteen colonies of five different genotypes of endangered staghorn corals (Acropora cervicornis) were transplanted to the rubble zone in front of the Coral City Camera by Rescue a Reef, a citizen science program based at the University of Miami. The goal of this experiment was to try and identify stress-tolerant strains of staghorn corals to better inform Rescue a Reef of the strains best suited for near-shore habitats. We anticipated that not all the strains would survive (or perhaps none would survive), but given that this was a science experiment using clones, any mortality would be offset by the fact that dozens to hundreds of more clones exist in Rescue a Reefs offshore coral nurseries. The results greatly exceeded our best expectations!

As far as we are aware, this is the longest continuous in-situ growth timelapse of corals ever made!

This timelapse begins on June 28, 2021, just a few days after transplantation and replacing the CCC (which slightly altered the perspective). Over the course of the next several weeks, tissue die-off progressed rapidly across many of the colonies (Seen as bright white skeleton before being overgrown with brown algae). However, after a month of acclimation, the staghorn corals stabilized and adapted to their new Anthropogenic habitat despite water temperatures exceeding 90 (32C) in August and September (but no significant coral bleaching was observed!). Over the course of this time, the perspective shifts slowly as the Camera slowly subsides in the sediment and leans away from the rubble zone (due to the powerful currents in the area).

Ongoing research with University of Miami, NOAA, and Penn State University is now looking into the microbiomes of these staghorn corals to compare how they may have changed from their offshore clones. We observed on a night dive in September of 2021 while filming the ‘Coral City Fluorotour‘ that these staghorn corals were expressing fluorescent green proteins which is unusual for the species, and isn’t observed in their offshore counterparts. Unlocking the secrets of these urban-adapted ‘super corals’ is just the next step in understanding their remarkable resilience. Perhaps the site around PortMiami is ideal for evolutionarily assisting and stress-adapting corals before out-planting to the beleaguered nearshore reefs around Miami.

Just as the new coral growth is interesting to watch, equally interesting is to witness the erosion and disappearance of the dead staghorn branches of the colony closest to the Camera. This erosion occurs from the parrotfish whose powerful beak-like teeth can rasp the surface layer of algae while crunching the limestone skeleton (and then pooping sand). The club-tipped finger coral (Porites porites) in the lower right corner of the view is also interesting to observe over the year, as the parrotfish are fond of eating the healthy branch tips, rendering them very club-like in Coral City!

Playback speed is at 15 frames (days) per second (about one month per 2 seconds).

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