Coralline algae are important reef-builders which can form nodules, known as rhodoliths, occurring worldwide in beds sustaining a high biodiversity. Although considered a non-renewable resource, they are exploited as a source of calcium carbonate used mainly for agricultural purposes. In Brazil between 96,000 and 120,000 metric tonnes of rhodoliths are extracted per year. Besides the direct impact caused by removal on the coralline bed, the dredge process may also produce a plume of fine sediment, which can change the primary production of the remaining organisms. In this study, four treatments, with three replicates, were used to acquire Lithothamnion sp. net photosynthetic rates with and without a sediment layer using a Clark-type oxygen microelectrode and micromanipulator. The results demonstrated that, under controlled conditions, the addition of a thin sediment layer resulted in a 30% reduction of the irradiance, decreasing the Lithothamnion sp. net production in 70%. For this reason direct and indirect effects of mechanical exploitation of the rhodolith beds should be included in future studies that focus on environmental impacts of dredging activity, whether it is linked to the extraction of these algae.

The orange cup coral Tubastraea coccinea was the first scleractinean to invade the western Atlantic. The species occurs throughout the Gulf of Mexico and the Caribbean Sea and has now established itself in the southwest Atlantic along the Brazilian coast. T. coccinea modifies native benthic communities, competes with an endemic coral species and demonstrates widespread invasive potential. We used species distribution modeling (SDM) to predict climatically suitable habitats for T. coccinea along the coastline of the southwestern Atlantic and identify the extent of the putative effects of this species on the native coral Mussismilia hispida by estimating areas of potential overlap between these species. The resulting SDMs predicted a large area of climatically suitable habitat available for invasion by T. coccinea and also predicted widespread occurrence of the endemic M. hispida along the Brazilian coast. The prediction of the T. coccinea distribution model suggests that suitable environmental conditions for the species occur throughout most of the littoral zone, including most of Brazil's marine protected areas. The overlap of the SDMs of M. hispida and T. coccinea revealed a large area with high habitat suitability for both species. Considering the invasive potential of T. coccinea and its ecological consequences, we concluded that this alien species could change the benthic communities of most of the shallow Brazilian coast and, as the invasive and native coral species have been shown to be antagonistic, T. coccinea represents a serious threat to M. hispida throughout most of its potential geographical distribution.

ResumoO presente trabalho teve como objetivo verificar a dinâmica reprodutiva e estrutura populacional da espécie Hoplias aff. malabaricus, no açude Taperoá II, localizado na Bacia do Rio Taperoá, no Cariri paraibano (07º11'44"S, 07º13'44"S). Foram coletados (nos meses de agosto a dezembro de 2002, janeiro a fevereiro e maio a junho de 2003) 67 indivíduos, por meio de redes de espera e tarrafa. A interferência do regime de chuvas no comportamento reprodutivo e no crescimento da espécie foi observada após a análise macroscópica das gônadas dos exemplares coletados.Unitermos: Semi-Árido paraibano, relação peso/comprimento, grau médio de maturação gonadal AbstractReproductive dynamics and population structure of Hoplias aff. malabaricus (Bloch, 1794) (Characiformes, Erythrinidae) in the dam lake of the Taperoá River Basin, Paraíba. This work aims to verify the reproductive dynamics and growth of the Hoplias aff. malabaricus species in the Taperoá II dam lake (07º11'44"S, 07º13'44"S), located in the basin of the River Taperoá in the Cariri region of Paraiba. Sixty-seven individuals were collected (August-December 2002, January-February, May and June 2003) by means of gillnets and cast nets. The interference of the rain regimen in the reproductive behavior and the structure of growth of the species were observed after the macrocospic analysis of the gonads of the collected units.Key words: Paraiban semi-arido, relation length/weight, average degree of gonadal maturati Biotemas, 22 (2): 85-89, junho de 2009

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ResumoPartículas plásticas constituem um dos poluentes mais comuns no ambiente marinho e atingem inclusive regiões com baixa densidade populacional humana. Frequentemente, essas partículas são ingeridas por diversos organismos marinhos, ocasionando problemas no trato digestivo, que podem culminar no enfraquecimento e morte do animal. Em um estudo acerca da alimentação de 631 Atobás-mascarados, Sula dactylatra, na Reserva Biológica do Atol das Rocas, foram encontradas partículas plásticas no conteúdo estomacal de quatro indivíduos adultos. Os artefatos plásticos encontrados constituíam-se de um plástico transparente, um pedaço de rótulo de garrafa de água mineral, dois pedaços de plástico preto e um pedaço rígido pequeno e vermelho. O fluxo de embarcações, tanto pesqueiras quanto turísticas, no entorno da ReBio Atol das Rocas pode ser a fonte de origem das peças plásticas tanto nos conteúdos estomacais quanto os encontrados nas ilhas da reserva, evidenciando que ações antropogênicas já atingem áreas isoladas, as quais deveriam ter um elevado grau de proteção da biodiversidade. Diversas medidas podem ser tomadas para evitar eventos deletérios na biota marinha, porém há uma grande dificuldade em evitar o descarte de lixo proveniente de navios pesqueiros e de turismo, além dos materiais vindos do continente, sendo necessário um incremento nos esforços de conscientização e fiscalização. Palavras-chave: Lixo marinho; Poluição; Sulidae; Unidade de conservação AbstractPlastic ingestion by Masked booby, Sula dactylatra Lesson, 1831, on Biological Reserve of Rocas Atoll, RN, Brazil. Plastic particles are one of the most common pollutants in the marine environment and it is reaching regions with low human population density. These particles are frequently ingested by many marine organisms, causing digestive problems, which may lead to the weakening and death of the animal. In a research on the feeding of 631-masked boobies, Sula dactylatra from the Biological Reserve of Atol das Rocas, plastic particles were found in stomach contents of four adults. The artifacts found were made of transperant plastic, a piece of label of a mineral water bottle, two pieces of black plastic and a small hard and red piece. The flow of