Browsing by Author "Manso, R.C.C."

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    Seaweed diversity associated with a Brazilian tropical rhodolith bed
    (Universidad Autónoma de Baja California, 2010) Amado-Filho, Gilberto M.; Maneveldt, Gavin; Pereira-Filho, G.H.; Manso, R.C.C.; Bahia, Ricardo
    This study describes the predominantly tropical, subtidal seaweed populations growing on rhodoliths between 4 and 18 m depth in the southern part of Espírito Santo State (Brazil). Qualitative and quantitative sampling revealed species-rich algal communities, comprising 167 species. Three species of rhodophytes represent new records for the Brazilian marine flora (Lithothamnion muelleri, Scinaia aborealis, and Mesophyllum engelhartii). Marked seasonal differences in fleshy algal species composition and abundance were related to seasonal instabilities caused by winter-storm disturbance over the rhodolith beds. In relation to depth, rhodolith density appears to be an important factor for the variation in the abundance of fleshy algae. The rhodolith community is composed of at least seven nongeniculate crustose coralline algal species. Rhodolith beds in southern Espírito Santo State, in an area of 150 km2, provide an important habitat for epibenthic communities, supporting 25% of the known macroalgal species richness along the Brazilian coast.
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    Structure of rhodolith beds from 4 to 55 meters deep along the southern coast of Espírito Santo State, Brazil
    (Universidad Autónoma de Baja California, 2007) Amado-Filho, Gilberto M.; Maneveldt, Gavin; Manso, R.C.C.; Marins-Rosa, B.V.; Pacheco, M.R.; Guimarães, S.M.P.B.
    Rhodoliths are one of the most extensive benthic communities of the Brazilian continental shelf, but their structure is poorly known. The richest marine flora of Brazil’s coastal zone is found in Espírito Santo State and its diversity has been partly associated with the presence of extensive areas of rhodoliths, extending from the intertidal zone to 120 m across the continental shelf. One species of kelp, Laminaria abyssalis, is endemic to this area and occurs between 45 and 120 m depth. Our objective was to determine the density and physical dimensions of the superficial rhodoliths between 4 and 55 m depth in the southern region of Espírito Santo State. The study area was 3 to 45 km offshore. Samples were obtained in 2004 and 2005 by Scuba diving in three depth zones: 4–18 m, 25–30 m and 50–55 m. Transect lines and video images were used to determine rhodolith density. The diameter and sphericity of at least 60 individuals from each zone were measured. Rhodolith size increased and density decreased from the shallow to the deeper zones. Spheroidal was the typical shape throughout the depth zones. Five rhodolith-forming genera were identified: Lithothamnion, Lithophyllum, Hydrolithon, Neogoniolithon and Sporolithon. Epibenthic biomass and species richness over the rhodolith bed in the shallow zone was lowest in winter, likely the result of disturbance caused by typical winter storms. Changes in light and temperature are probably the most important factors in the changes observed in the rhodolith beds from the deepest zones.