Few studies have described the spatial patterns of rocky sublittoral benthic communities in Brazil, where these habitats are almost exclusively located on the southeast and south coastline. The fauna and flora were analyzed using a quadrat method, and the species abundance and distribution were determined along transects down to the bottom sand plain on 10 rocky shores at Armação dos Bú zios, Brazil. The 16 most common species accounted for around 97% of the benthos coverage and included cnidarians, algae, poriferans, and echinoderms. Cnidarians and algae were the most important groups, with abundance ranging from 13-66% and 27-68%, respectively. The species distribution indicated a clear depth zonation pattern. The algal community dominated the shallowest depths in sites more exposed to waves and steeper substrate slope, whereas the cnidarian community, divided into the zoanthidean Palythoa caribaeorum and the coral Siderastrea stellata, was more abundant from intermediate to greater (4 m) depths. Different community patterns were found between sites, demonstrating that different spatially discrete factors may be acting on each rocky shore. ProblemCommunities can be described in terms of pattern of species abundance and distributions in time and space. Spatial distributions occur at different scales of resolution. Recently, many studies have documented spatial variability at small to large

Although a dense cover of epiphytes is generally considered to be harmful for some coralline algae (Corallinaceae, Rhodophyta), crustose corallines in the littoral zone seem to be preserved from bleaching when covered by canopy plants and epiphytes during summer. This study aimed to test the responses of coralline crusts to epiphytes and canopy algae and their interaction with grazing limpets. Growth rates and color changes were followed in two crust species in areas with or without canopy algae in the Isle of Man, British Isles. Limpets were excluded, to allow epiphytes to grow upon crusts. Responses were measured both on pieces of crusts upon acrylic plates and on crusts growing naturally on the shore. Fucus canopy and epiphytic Enteromorpha significantly influenced the crusts' growth, depending on season. Epiphytes reduced the light levels beneath by up to 78%, more than the canopy algae (62%). Crusts exposed outside the canopy bleached in summer, but gradually restored their color once they were covered by epiphytes. The fast‐growing Phymatolithon lenormandii (Aresch.) Adey recovered its coloration more quickly than the slow‐growing P. purpureum (P. et H. Crouan) Woelkerling et Irvine. However, neither crust species could restore its color when epiphytes were reduced by grazing limpets, Patella vulgata L. Bleaching did not kill the crusts, but seemed to interfere with crusts' growth. Restoration of pigmentation was quantified for the first time on bleached coralline crusts. Epiphyte and canopy algae were experimentally shown to be beneficial, probably by providing shade and also protecting crusts from desiccation.

An updated synthesis of cyanobacteria and algae information is presented for Brazil aiming to refine the data gathered to date and evaluate the progress of the biodiversity knowledge about these organisms in the country since the publication of the Catálogo de Plantas e Fungos do Brasil. The results of 2015 showed an increase of 1,250 species (35.7%) when compared to 2010, reaching a total of 4,747 species. The most diverse classes in species number were the Bacillariophyceae, Conjugatophyceae, Florideophyceae, Cyanophyceae, Dinophyceae and Euglenophyceae. Bacillariophyceae and Cyanophyceae had the highest increase in species number in the five-year interval. The Southeast and South regions were the most diverse, however, the Northeast, with the states of Piauí and Sergipe, and the Central-west region, with Mato Grosso, Goiás and Distrito Federal, also stood out in the national algal biodiversity scenario. Despite the shortage of taxonomists and limited infrastructure, the results showed a significant improvement in the knowledge regarding the diversity of cyanobacteria and algae in the country during the study period, starting to even out regional geographical differences caused by subsampling. Key words: Biodiversity, phycology. ResumoApresenta-se uma síntese atualizada de informações sobre algas no Brasil objetivando refinar os dados reunidos até o presente, bem como avaliar os avanços sobre o conhecimento da diversidade de algas no país desde a publicação do Catálogo de Plantas e Fungos do Brasil. Os resultados de 2015 mostraram um acréscimo de 1.250 espécies (35.7%) a um total de 4.747 em relação a 2010. As classes mais diversas em número de espécies foram Bacillariophyceae, Conjugatophyceae, Florideophyceae, Cyanophyceae, Dinophyceae e Euglenophyceae. Bacillariophyceae e Cyanophyceae tiveram o maior acréscimo de espécies no intervalo de cinco anos. A região Sudeste e Sul foram as mais diversas, porém, as regiões Nordeste com os estados do Piauí e Sergipe e Centro-Oeste com os estados de Mato Grosso, Goiás e Distrito Federal destacaram--se no cenário da biodiversidade nacional. Apesar da escassez de taxonomistas e da infraestrutura limitada, os resultados obtidos evidenciaram um avanço significativo no conhecimento da diversidade de algas no país nesse período de cinco anos, iniciando uma mudança quanto as diferenças geográficas regionais. Palavras-chave: Biodiversidade, ficologia.

Financial Support: CNPQ, CAPES, FAPESP.Rhodolith beds are important marine benthic ecosystems, representing oases of high biodiversity among sedimentary seabed environments. They are found frequently and abundantly, acting as major carbonate 'factories' and playing a key role in the biogeochemical cycling of carbonates in the South Atlantic. Rhodoliths are under threat due to global change (mainly related to ocean acidification and global warming) and local stressors, such as fishing and coastal run-off. Here, we review different aspects of the biology of these organisms, highlighting the predicted effects of global change, considering the additional impact of local stressors. Ocean acidification (OA) represents a particular threat that can reduce calcification or even promote the decalcification of these bioengineers, thus increasing the ecophysiological imbalance between calcareous and fleshy algae. OA should be considered, but this together with extreme events such as heat waves and storms, as main stressors of these ecosystems at the present time, will worsen in the future, especially if possible interactions with local stressors like coastal pollution are taken into consideration. Thus, in Brazil there is a serious need for starting monitoring programs and promote innovative experimental infrastructure in order to improve our knowledge of these rich environments, optimize management efforts and enhance the needed conservation initiatives. AbstrActDescriptors: Algae, Conservation, Brazil, Global warming, Pollution, Ocean acidification.Bancos de rodolitos formam oásis de alta biodiversidade em ambientes marinhos de fundo arenoso. Os rodolitos são formados por espécies bioconstrutoras, que fornecem abrigo e substrato para diversas e abundantes comunidades bentônicas. No Brasil esses ambientes são frequentes, representando grandes "fábricas" de carbonato com um papel fundamental no ciclo biogeoquímico do carbono no Atlântico Sul. Estes organismos e ambientes estão ameaçados pelas mudanças climáticas (principalmente a acidificação dos oceanos e o aquecimento global) e pelos estressores locais, tais como os impactos causados pela pesca e as descargas costeiras de efluentes. Neste trabalho fazemos uma revisão da taxonomia, filogenia e biologia desses organismos, com destaque para os efeitos previstos das mudanças climáticas e suas relações com estressores locais. A maioria dos estudos acerca dos efeitos das mudanças climáticas e da acidificação dos oceanos em algas calcárias relatam respostas negativas não só no crescimento e na calcificação, mas também no processo de fotossíntese, espessura da parede celular, reprodução e sobrevivência das algas. Este cenário reforça a necessidade em estabelecer uma consistente rede de trabalho para proporcionar um programa de monitoramento amplo e de longo prazo, bem como infraestrutura para avaliações experimentais de impactos locais e regionais das mudanças climáticas e dos estressores locais em bancos de rodolitos.

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