No abstract

ResumoA riqueza de espécies de Oligochaeta foi investigada em duas represas construídas no curso do rio Tietê. Em cada represa foram obtidas 360 amostras de sedimento em 90 pontos de amostragem, utilizando-se uma draga Van Veen (378cm 2 ), nos meses de janeiro, abril, julho e outubro de 2001. No total foram examinados 12.826 exemplares de oligoquetos pertencentes a 20 espécies, 10 gêneros e 4 famílias. Naididae e Dero foram a família e o gênero com maiores riquezas de espécies, com 14 e 9 espécies, respectivamente. Do total de espécies identificadas, 6 estiveram presentes em ambas represas, sendo Branchiura sowerbyi (Tubificidae) a espécie mais abundante nestes ambientes. A análise das amostras revelou que a maioria das espécies de oligoquetos é rara e de freqüência de ocorrência acidental, evidenciando que para um melhor conhecimento da riqueza de espécies é realmente necessário um grande esforço amostral, com elevado número de pontos de amostragem. AbstractThe species richness of Oligochaeta was evaluated in two reservoirs belonging to Tietê River system, Bariri and Ponte Nova Reservoirs. 360 sediment samples were taken in each reservoir at 90 sampling stations using a Van Veen grab (378cm 2 ), in the months January, April, July and October 2001. A total of 12.826 oligochaete specimens were collected, belonging to 20 species, 10 genera and 4 families. The family and genus with the highest species richness were Naididae and Dero, with 14 and 9 species, respectively. Among all species identified 6 occurred in both reservoirs, being Branchiura sowerbyi (Tubificidae) the most abundant species in them. The study also revealed that most Oligochaeta species are rare and have accidental occurrence, thus evidencing that for a better knowledge of species richness is actually necessary a great sampling effort including a large number of sampling points.Biota Neotropica v5 (n1) -http://www.biotaneotropica.org.br/v5n1/pt/abstract?article+BN00605012005

Na comunidade de Barra Grande localizada no litoral do Piauí, as mulheres dos pescadores, conhecidas localmente como marisqueiras, extraem do manguezal vários tipos de moluscos para comercialização e em maior escala para a subsistência. Dados sobre a atividade de mariscagem, conceitos de conservação e aspectos socioeconômicos do contexto em que ocorre a atividade de cata dos moluscos, foram revelados após a aplicação de protocolos estruturados e semiestruturados. O molusco bivalve Anomalocardia brasiliana (Gmelin, 1791), popularmente denominado de marisco, é caracterizado por ser um importante recurso para a subsistência, sendo o mais coletado pela comunidade, seguido da Mytella charruana (d'Orbigny, 1842), o sururu, explorado para a comercialização por ter o maior valor de mercado. O conhecimento das marisqueiras sobre A. brasiliana foi comparado com literatura especializada, muitas vezes mostrando-se em harmonia com esta. Demonstra-se assim que o conhecimento tradicional deve ser valorizado para delineamento de programas de gestão de recursos pesqueiros da região. Quanto aos modos de pensar, foi revelado que 82,81% das marisqueiras praticam manejo para a conservação da A. brasiliana ao coletar apenas os indivíduos de maior tamanho, e 80,86% consideram que não existe poluição nos pontos de coletas. O surgimento de uma Associação exclusiva e cooperativa para as marisqueiras é necessário para a valorização do trabalho por elas desenvolvido, visto que há uma média estimada de 351 kg de carne sendo extraídos mensalmente.

Antihypertensive pharmaceuticals, including the beta-blockers, are one of the most detected therapeutic classes in the environment. The ecotoxicity of propranolol hydrochloride and losartan potassium was evaluated, both individually and combined in a binary mixture, by using the Lemna minor growth inhibition test. The endpoints evaluated in the single-pharmaceutical tests were frond number, total frond area and fresh weight. For the evaluation of the mixture toxicity, the selected endpoint was frond number. Water quality criteria values (WQC) were derived for the protection of freshwater and saltwater pelagic communities regarding the effects induced by propranolol and losartan using ecotoxicological data from the literature, including our data. The risks associated with both pharmaceutical effects on non-target organisms were quantified through the measured environmental concentration (MEC)/predicted-no-effect concentration (PNEC) ratios. For propranolol, the total frond area was the most sensitive endpoint (EC50 = 77.3 mg L(-1)), while for losartan there was no statistically significant difference between the endpoints. Losartan is only slightly more toxic than propranolol. Both concentration addition and independent action models overestimated the mixture toxicity of the pharmaceuticals at all the effect concentration levels evaluated. The joint action of both pharmaceuticals showed an antagonistic interaction to L. minor. Derived WQC assumed lower values for propranolol than for losartan. The MEC/PNEC ratios showed that propranolol may pose a risk for the most sensitive aquatic species, while acceptable risks posed by losartan were estimated for most of aquatic matrices. To the authors knowledge these are the first data about losartan toxicity for L. minor.

Benthic communities are highly relevant in the study of aquatic ecosystems, both for their role in the functioning of the ecosystem and also as markers or indicators of paleo-conditions. Their distribution, as in other communities, is conditioned by abiotic and biotic factors and to their interactions, which determine the structure of the community that is established. The aim of this study was to determine the taxonomic composition, abundance and spatial distribution of the benthic community, by collecting at 20 sampling sites in Caçó Lake (State of Maranhão, Brazil). Seasonal variation in these community parameters was analysed and related to the seasonal displacement of the Intertropical Convergence Zone. The results indicated that changes occur in the taxa richness, diversity and density of the benthic species of this lake that are mainly related to seasonality. All those parameters were higher in the dry than in the rainy period. The family Chironomidae (Diptera, Insecta) was the most important component of the community, representing approximately 50% of the total benthic fauna of the lake. The identification of the Chironomidae currently occurring in Lake Caçó is relevant, even at the genus level, considering the fact that this group produces fossilizing remains and could perhaps be good paleolimnological and paleoclimatic tracers that could be used to make inferences on past lake and climate conditions. Keywords: benthic community, Chironomidae, Lake Caçó, tropical Limnology, macroinvertebrates. Macroinvertebrados bentônicos de um lago tropical: lago Caço, MA, Brasil ResumoAs comunidades bentônicas são relevantes nos ecossistemas aquáticos devido ao seu papel no seu funcionamento e também como marcadores ou indicadores de paleocondições. Sua distribuição, similarmente à de outras comunidades, é condicionada por fatores abióticos e bióticos e pela interação entre eles, determinando a estrutura da comunidade que se estabelecerá. O objetivo do presente trabalho foi determinar a composição taxonômica, a abundância e a distribuição espacial da comunidade bentônica, amostrando-se em 20 pontos na lagoa do Caçó (Estado do Maranhão, Brasil). As variações sazonais nas características desta comunidade foram analisadas e relacionadas ao deslocamento sazonal da Zona de Convergência Intertropical. Os resultados indicaram que ocorrem mudanças na riqueza de taxons, diversidade e densidade da comunidade bentônica deste lago que são principalmente relacionadas à sazonalidade. Todas as variáveis analisadas foram maiores no período seco do que no chuvoso. Os organismos pertencentes à família Chironomidae (Diptera, Insecta) foram os mais importantes componentes da comunidade, representando aproximadamente 50% do total da fauna. A identificação dos Chironomidae atualmente presentes no Lago Caçó, mesmo em nível de gênero, é relevante, considerando-se o fato de que as larvas deste grupo produzem remanescentes fósseis que podem ser bons traçadores paleolimnológicos e paleoclimáticos, podendo ser utilizados para fazer inf...

Codium fragile subsp. fragile (Suringar) Hariot is a large, dichotomously branched green alga that has invaded many temperate locations around the globe. Despite its wide distribution and pest status, there are few accounts of Codium fragile subsp. fragile that provide morphological descriptions, including illustrations, for comparison. In 2008, a seaweed sample suspected to be Codium fragile subsp. fragile was collected from Albany, Western Australia. As this taxon superficially resembles other local erect and dichotomously branching Codium species, a detailed morphological and molecular analysis of the suspect alga was conducted. Investigations confirmed the identity of this alga as the invasive subspecies Codium fragile subsp. fragile. This represents the first record of this species in Western Australia.

In the present study, we report the presence of the nereidid polychaete Laeonereis acuta near to the estuarine areas of Parnaíba River, extending its distribution towards the north of the northeastern Brazilian coast.

Purpose-The São Lourenço River (SLR) is used to supply potable waters for the cities of São Lourenço da Serra and Juquitiba, but receives the residues from the water treatment plants (WTPs) and sewage treatment plants (STPs), respectively. The purpose of this paper is to evaluate the impacts of the discharges of Juquitiba's WTP and STP on the quality of the SLR, by using an integrated approach based on different lines of evidence. Design/methodology/approach-Six sampling sites were established along the river and comprised areas situated upstream and downstream of the discharges. Five sampling surveys were performed between 2004 and 2006 for collecting water and sediment samples for ecotoxicological assays. In two of these campaigns, benthic community structure and geochemistry (metals, nutrients and sediment texture) were also assessed. Findings-Concentrations of P, Fe and Al in waters exceeded the national standards, but sediments were not considered to be contaminated by metals or nutrients. Water and sediments tended to exhibit marginal toxicities, excluding the sediments from JQT007 and JQT008 that were frequently toxic. Combination of geochemistry, toxicity and ecological indices indicated that some sites are not degraded, but in some stations the benthic alteration may be due to non-measured contaminants, especially in JQT007 and JQT008. Practical implications-As the use of waters from SLR for public supply has increased, these results show that action should be taken in order to reverse the environmental degradation of SRL. Originality/value-This research combined sediment and water quality assessments in order to provide a more suitable and reliable diagnostic of the environmental quality of the SLR.