Brazilian Deep-Sea Corals

Abstract

The Brazilian Continental Margin (BM) hosts one of the most poorly known deep-water fauna in the world, especially those referred to as habitat forming such as scleractinians and octocorallians (Cnidaria: Anthozoa). In waters deeper than 150 m, these anthozoans are the framework builders for coral reefs and coral gardens. Together, these habitats host the highest diversity of metazoans on the external shelf and slope. Although only a few surveys have been dedicated to the study of these organisms in the BM, it is known that Desmophyllum pertusum (former Lophelia pertusa), Solenosmilia variabilis, and Madrepora oculata form extensive reefs especially on the southern and southeastern regions. In the same way, Octocorallia representatives, such as those of the families Priminoidae, Clavulariidae, Plexauridae, Alcyoniidae, Isididae, Coralliidae, and Paragorgidae, also have great ecological importance at the BM and are particularly abundant at the northern and northeastern continental shelves and slope. In order to set a baseline for future research, the present chapter provides a historical review of the studies of these anthozoans from the BM, including a list of all records and their geographical and depth distributions. Based on part of these records, the BM distributional modeling of these organisms is predicted using habitat suitability models, which suggest that carbonate saturation state, temperature, dissolved oxygen, and particulate organic carbon are the main factors structuring habitat suitability along the BM. In addition, a comprehensive review of the studies focusing on reproduction of the main species occurring at the BM, a key process for the maintenance and renewal of coral populations and, therefore, design of marine protected areas, as well as the human-based impacts imposed to the habitats structured by these species, are provided.