A description of the phytobenthic community structure in five sites of Sepetiba Bay, RJ, is presented. Sampling was done in the four seasons of the year 1999 (January, May, August, November), from sites at the inner bay region, directly subjected to the local anthropic impacts, to sites at the region close to the open sea, where the human interference is reduced. Destructive sampling method was used. Comparisons were based on the following parameters: species number, total biomass, diversity (H') and equitability (J). Ninety six taxa were identified: 61 rhodophytes, 18 chlorophytes, 15 phaeophytes and two cyanophytes. The highest number of taxa (65) and highest biomass values (492.4 g.m-2) were found at site 5, located on Marambaia point. An increase in the diversity was seen from the inner bay to the open ocean region. Considering the biomass, Sargassum spp. were the most important macroalgae, followed by Padina gymnospora and other algae shorter in size as Hypnea spp., Gelidium pusillum, Pterocladiella caerulescens and Gelidiopsis spp. The utilization of the destructive sampling method allowed a detailed characterization of the composition and structure of Sepetiba Bay phytobenthic community, facilitating on the future, the identification of changes imposed to the algal community by using more simple methodological approaches.
biomass; diversity; macroalgae; pollution gradient
