The clarity of the water in the coral reef systems allow the sunlight to penetrate deep resulting in the high level of photosynthesis in the algae present inside the coral. Coralline algae are red algae in the order CorallinalesThey are characterized by a thallus that is hard because of calcareous deposits contained within the cell walls. Posts About Coral Reef Poster On Rolling Harbour Abaco Coral Reef Science And Nature Oceanography Atolls are usually circular or oval with a central lagoon. . Army veterans scientists and members of Force Blue the Guy Harvey Ocean Foundation and other organizations took part in a dive to. If a fringing reef forms around a volcanic island that sinks completely below sea level while the coral continues to grow upward an atoll forms. We are dedicated to creating offshore nurseries and restoration programs for threatened coral species. The trees trap sediment and pollutants that would otherwi...