Coralline Red Algae and Rhodolith Beds: A World Natural Heritage in the Southwestern Atlantic

In this book, we will discuss different aspects of the coralline red algae (CRA) and their rhodolith beds. Besides being the main builders of these biogenic reefs, they are also an important constituent of coral reefs, with important interconnections and interdependencies among these systems. Recent advancements in the characterization of the community structure of biogenic reefs in the South Atlantic revealed unique reef formations as the Rocas Atoll and the Abrolhos “chapeirões,” where CRA are majorly responsible for the construction and maintenance of these formations. In order to contextualize the long evolutionary process of calcareous algae, as well as the origin of the coralline marine flora in the Southwestern Atlantic, we briefly present the main geological events and the role of ecophysiological barriers and filters to understand the distribution pattern of the current flora. We discussed some of the main threats to this group of organisms and highlighted the unquestionable ecological importance of CRA and their role in the reefs of the Southwestern Atlantic. Finally, we reinforce their contribution to people and our needs to foster their conservation in the Blue Amazon as a world natural heritage.