Marina N. Sissini (Universidade Federal de Santa Catarina)
Rhodoliths are free forms of calcareous red algae and play a fundamental role in the construction of biogenic reefs, including coral reefs. With advances in the characterization of reef systems in the Southwestern Atlantic, unique reef formations have been revealed, where calcareous algae are the main builders of these formations, such as the Rocas Atoll, the “chapeirões” of Abrolhos and, the Coralline Hills of Vitória-Trindade Chain. In Brazil, these aggregations extend from the mouth of Amazonas River to Santa Catarina, and can occupy up to 230,000 km2, according to predictive models. Rhodolith beds are considered “ecosystem engineers”, being responsible for creating and maintaining marine habitats for a wide diversity of organisms, and at different stages of their life cycles. Despite its slow growth, rhodolith beds represent one of the largest carbonate deposits in the world, being important carbonate biofactories and long-term carbon storage. Rhodolith beds still receive little attention and have many gaps in relation to its distribution, composition and diversity patterns. Furthermore, like other marine organisms, rhodoliths are under local and global impacts, which will be presented and discussed, highlighting their ecological importance and contribution to people to promote their conservation in the Blue Amazon as a world natural heritage.