RESUMO O gênero Caulerpa constitui um importante componente da flora ficológica no litoral do Nordeste brasileiro. A presente pesquisa teve como objetivo identificar, descrever e fornecer informações acerca da distribuição e ecologia das espécies do gênero Caulerpa no litoral do Estado de Alagoas, contribuindo para o conhecimento da flora fico- lógica brasileira, nesse trecho do litoral do Nordeste ainda pouco estudado. Os espécimes foram coletados em seis praias ao longo do litoral alagoano. Foram analisadas também exsicatas de Caulerpa depositadas no Herbário MAC, do Instituto do Meio Ambiente de Alagoas (IMA). Foram identificados quatorze táxons infragenéricos, distribuídos em doze espécies e três variedades, coletados em substratos rochosos e arenosos. Neste trabalho são reportadas pela primeira vez a ocorrência de C. cupressoides var. flabellata, C. kempfii, C. mexicana, C. microphysa, C. verticillata e Caulerpa sp. para o litoral de do Estado de Alagoas.

ABSTRACT The genus Caulerpa is an important component of the phycological flora from the Brazilian Northeast Coast. The aim of the present research was to identify, describe and provide information about the distribution and ecology of the species of this genus at the coast of Alagoas State, contributing to the knowledge of the Brazilian phycolo- gical flora, which is poorly known in this regionThe specimens were collected from six beaches along the coast of Alagoas State. Caulerpa exsiccates deposited in the MAC Herbarium of the Environmental Institute of Alagoas were also analyzed. Fourteen infrageneric taxa were identified, distributed into in twelve species and three varieties, growing on rocky and sandy substrates. In this work, it is reported for the first time on the coast of Alagoas the occurrence of C. cupressoides var. flabellata, C. kempfii, C. mexicana, C. microphysa, C. verticillata and Caulerpa sp.

The diversity of algal banks composed of species out the genera Gracilaria Greville and Hypnea J.V. Lamouroux have been impacted by commercial exploitation and coastal eutrophication. The present study sought to construct dynamic models based on algal physiology to simulate seasonal variations in the biomasses of Gracilaria and Hypnea an intertidal reef at Piedade Beach in Jaboatão dos Guararapes, Pernambuco State, Brazil. Five 20 × 20 cm plots in a reef pool on a midlittoral reef platform were randomly sampled during April, June, August, October, and December/2009 and in January and March/2010. Water temperature, pH, irradiance, oxygen and salinity levels as well as the concentrations of ammonia, nitrate and phosphate were measured at the sampling site. Forcing functions were employed in the model to represent abiotic factors, and algal decay was simulated with a dispersal function. Algal growth was modeled using a logistic function and was found to be sensitive to temperature and salinity. Maximum absorption rates of ammonia and phosphate were higher in Hypnea than in Gracilaria, indicating that the former takes up nutrients more efficiently at higher concentrations. Gracilaria biomass peaked at approximately 120 g (dry weight m-2) in March/2010 and was significantly lower in August/2009; Hypnea biomasses, on the other hand, did not show any significant variations among the different months, indicating that resource competition may influence the productivity of these algae.