Species composition and distribution of macroalgae on Atol das Rocas, Brazil, SW Atlantic

Abstract

This study, performed over the years 1999–2003, analyzed the species composition, spatial distribution and ecological aspects of macroalgal assemblages on Atol das Rocas reef, located 266 km off northeastern Brazil. It is the sole atoll in the South Atlantic and is almost completely built of coralline algae. Forty-seven new occurrences of macroalgae were recorded. Adding these to the previous studies, 143 taxa are now known for the local marine flora, with the Rhodophyta as the dominant group. New finds were mainly on the fore reef and in reef pools. The inner habitats (the reef flat, internal ridge and inner pools) harbored fewer macroalgal species than the outer habitats (the reef front, reef crest crevices and outer pools). Inner habitats are subject to prolonged desiccation and solar irradiation stress together with abrupt changes in temperature and salinity controlled by the water oscillations of the mesotidal regime within the atoll; the outer habitats are less affected by these short temporal impacts and are mainly governed by oceanic forcing. Atol das Rocas harbors some species unknown in other Brazilian waters, but these are common in Caribbean reef waters.

Structure and temporal dynamic of tropical turf forming macroalgal assemblages of the western coast of Mexico

“…Rhodophyta, Chlorophyta and Ochrophyta (Phaeophyceae) richness found in Zihuatanejo Bay corresponds with reports from tropical regions (Tribollet et al, 2010;Villaça et al, 2010). The variability of abiotic conditions in the tropical zone is limited from the influence of the rainy season which can reduce salinity and increase water velocity (Mejia et al, 2012), such conditions may to explain the low richness in this season in Zihuatanejo Bay.…”

Composition and Distribution of Deep Water Macroalgae Species from the Continental Shelf of Sergipe State, Brazil

“…The R/P (Feldmann 1937) and (R+C)/P (Chenney 1977) indexes were used for describing geographical patterns according to seaweed phylum ratios (Figueiredo et al 2008, Villaça et al 2010.…”

Diversidade de Gelidiales (Rhodophyta) baseada em marcadores moleculares e estudos morfoanatômicos para região Sudeste do Brasil

“…As características morfológicas encontradas nesse espécime, como ausência de rizines por todo talo (Fan, 1961) e estrutura de fixação composta por filamentos rizoidais independentes (Perrone et al, 2006) Rocas, RN, como Gelidiella setacea (Creed et al, 2010;Oliveira, 1977;Oliveira Filho & Ugadim, 1976;Villaça et al, 2010). Esta espécie possui até 3,0 cm de altura e o diâmetro do ramo ereto pode alcançar 150-200 µm (Taylor, 1960), podendo apresentar ramificações.…”