Bleaching, algae, and a lionfish, OH MY!
Coral bleaching was the worst on record in Flower Garden Banks National Marine Sanctuary in 2016. The white corals are stressed, having suffered from prolonged, elevated water temperatures, and have expelled their symbiotic algae. The algae provides the color to the coral tissues, and it also provides the coral polyps with food by way of photosynthesis. Once the algae has left the coral tissue, the stark white calcium carbonate skeleton is visible through the transparent coral tissue, giving it a “bleached” appearance. If the water temperatures stay too high for too long, and the corals do not re-recruit their algae, corals may starve and die. Fortunately this was not the case - the water temperature has decreased, and the corals have been able to re-recruit their symbiotic algae and recover.
This magnificent sand flat is the largest accessible to recreational divers visiting the West Flower Garden Bank. The sand sits at 95 feet from the surface. In this case, note the large amount of algae visible throughout the sand flat, which could also be a result of 2016's warm water conditions. The round equipment rack that is also visible on the sand flat is used to mount a variety of instrumentation, including water quality sensors, an acoustic receiver, and a listening station.
Can you spot the lionfish silhouetted against the bleached coral? This invasive species is wreacking havoc throughout the Caribbean.