@misc{10481/74756,
year = {2022},
month = {4},
url = {http://hdl.handle.net/10481/74756},
abstract = {Rhodolith beds are biogenic benthic habitats mainly formed by unattached, non-geniculate
coralline algae, which can be inhabited by many associated species. The Brazilian continental shelf
encompasses the largest continuous rhodolith bed in the world. This study was based on samples
obtained from seven sites and videos taken by a Remotely Operated Vehicle (ROV) at four transects
off the Sergipe-Alagoas Coast on the northeast Brazilian shelf. ROV operations and bottom trawl
sampling revealed the occurrence of rhodolith beds between 25 and 54 m depths. At the shallower
depths, fruticose (branching) rhodoliths (maërl) appear in troughs of ripples, and other non-branching
rhodoliths occur associated with corals and sponge patches surrounded by bioclastic sand. Rhodoliths
also occur in patches from 30 to 39 m depth; some are fused, forming larger, complex tridimensional
structures. At deeper depths, from 40 to 54 m, the abundance of rhodoliths increases and occur
associated with fleshy macroalgae on a smooth seafloor; some rhodoliths are fused into complex
structures, locally some are fruticose (maërl), and others are partially buried by fine-grained sediment.
The collected rhodoliths vary from fruticose in two sites to encrusting to lumpy, concentric and
boxwork nodules in the rest; their size ranges from small (<1.5 cm) to large (~6 cm) and are mostly
sub-spheroidal to spheroidal. A total of 16 red algal morpho-taxa were identified in the study sites.
Two phases of growth can be distinguished in some rhodoliths by changes in color. The brownish
inner cores yielded ages of 1600–1850 cal years before the present, whereas outer layers were much
younger (180–50 years BP old). Growth layers appeared to have been separated by a long period of
burial in the seafloor sediment. Other rhodoliths have ages of hundreds of years.},
organization = {Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES)	001},
organization = {Fundacao de Amparo a Pesquisa do Estado do Rio de Janeiro-Jovem Cientista do Nosso Estado (FAPERJ/JCNE)},
publisher = {MDPI},
keywords = {Non-geniculate coralline read algae},
keywords = {Rhodolith beds},
keywords = {Maërl},
keywords = {Morpho-anatomy},
keywords = {ROV},
keywords = {Brazilian Northeast continental shelf},
title = {Structure and Composition of Rhodolith Beds from the Sergipe-Alagoas Basin (NE Brazil, Southwestern Atlantic)},
doi = {10.3390/d14040282},
author = {Vale, Nicholas F. L. and Braga Alarcón, Juan Carlos},
}