A stable isotope (d 13 C, d 15 N) model for the North Water food web: implications for evaluating trophodynamics and the flow of energy and contaminants. Deep-Sea Research II 49, 5131-5150. Hunt Jr., G.L., 1991. Occurrence of polar seabirds at sea in relation to prey concentrations and oceanographic factors.

The goal of this study was to document the distribution and establishment A. fulica such as their feeding preference and behavior in situ. The study was carried out at the city of Lauro de Freitas, Bahia state, Brazil, between November 2001 and November 2002. We used catch per unit effort methods to determine abundance, distribution, habitat choice and food preferences. The abundance and distribution of A. fulica was most representative in urban area, mainly near to the coastline. Lots and house gardens were the most preferred sites during active hours. The results indicated that A. fulica started their activity at the end of the evening and stopped in mid-morning.

The length-weight relationship and condition factor have been broadly investigated in snails to obtain the index of physical condition of populations and evaluate habitat quality. Herein, our goal was to describe the best predictors that explain Achatina fulica biometrical parameters and well being in a recently introduced population. From November 2001 to November 2002, monthly snail samples were collected in Lauro de Freitas City, Bahia, Brazil. Shell length and total weight were measured in the laboratory and the potential curve and condition factor were calculated. Five environmental variables were considered: temperature range, mean temperature, humidity, precipitation and human density. Multiple regressions were used to generate models including multiple predictors, via model selection approach, and then ranked with AIC criteria. Partial regressions were used to obtain the separated coefficients of determination of climate and human density models. A total of 1.460 individuals were collected, presenting a shell length range between 4.8 to 102.5 mm (mean: 42.18 mm). The relationship between total length and total weight revealed that Achatina fulica presented a negative allometric growth. Simple regression indicated that humidity has a significant influence on A. fulica total length and weight. Temperature range was the main variable that influenced the condition factor. Multiple regressions showed that climatic and human variables explain a small proportion of the variance in shell length and total weight, but may explain up to 55.7% of the condition factor variance. Consequently, we believe that the well being and biometric parameters of A. fulica can be influenced by climatic and human density factors.Keywords: Achatina fulica, alien species, gastropoda, condition factor, invasiveness species. Variáveis ambientais e humanas afetam o comprimento da concha, peso total e fator de condição de Achatina fulica (Gastropoda: Pulmonata)?Resumo A relação peso comprimento e o fator de condição têm sido bastante explorados em pesquisas envolvendo caracóis para obter o índice de condição física em populações e avaliar a condição do habitat. Neste trabalho, nosso objetivo foi descrever que variáveis influenciam os parâmteros biométricos e o bem estar de Achatina fulica em uma recente introdução. De novembro de 2001 a novembro de 2002, amostras mensais desses caracóis foram coletadas na cidade de Lauro de Freitas (Bahia), Brasil. Em seguida, os caracóis foram acondicionados em laboratório e foram obtidos o tamanho da concha e o seu peso. A partir desses dados a curva potencial e o fator de condição foram calculados. Cinco variáveis ambientais foram consideradas: amplitude de temperatura, temperatura média, humidade, precipitação e densidade humana. Regressões múltiplas foram usadas para gerar modelos preditivos através do critério de seleção e logo foram ordenados utilizando o critério de Akaíke. Regressões parciais foram usadas para obter os coeficientes de determinação do clima e fatores humanos. Um total de ...

ResumoEste trabalho apresenta a composição da ictiofauna e a análise espacial e sazonal da estrutura da comunidade de peixes das praias de Cabuçu (12º47'S -38º46'W -Saubara) e de Berlinque (13º06'S -38º45'W -Vera Cruz), Baía de Todos os Santos (13ºS -38ºW), estado da Bahia, Brasil. Os peixes foram coletados entre julho de 2002 e julho de 2003, durante a baixa-mar de marés de sizígia. Fatores abióticos, como pH, temperatura da água e salinidade, foram mensurados. A similaridade entre os locais de coleta foi analisada através da análise de Cluster, baseada sobre uma matriz de dados de presença-ausência das espécies, utilizando-se o coefi ciente de Sorensen. Um total de 719 peixes e 2231,77g de 63 espécies na praia de Cabuçu sendo que Lutjanus synagris, Larimus breviceps e Chaetodipterus faber dominaram. Na praia de Berlinque, foram coletados 381 peixes e 2605,64g, de 40 espécies. Polydactylus virginicus, Ophioscion punctatissimus e Conodon nobilis foram as espécies dominantes. Nenhuma tendência sazonal foi observada nos fatores abióticos, abundância e índices de comunidades de peixes nas duas praias. As rotinas ANOSIM e SIMPER do Primer demonstram que a composição ictiofaunística nas duas praias diferiu signifi cativamente.Unitermos: ictiofauna, praia de Cabuçu, praia de Berlinque, Baía de Todos os Santos, Bahia AbstractIchthyofauna of Cabuçu and Berlinque beaches: A comparative analysis of fi sh communities in Todos os Santos Bay, Bahia -Brazil. This study presents the composition of the ichthyofauna and the spatial and seasonal analysis of fi sh community structure at Cabuçu (12º47´S -38º46´W -Saubara) and Berlinque beaches (13º06´S -38º45´W -Vera Cruz) in Todos os Santos Bay (13ºS -38ºW), Bahia State, Brazil. Fish were collected between July 2002 and July 2003, during the lowest of the syzygial tides. Abiotic factors such as the pH, temperature and salinity of the water were measured. The similarity among the sampling sites was Biotemas, 21 (4): 105-115, dezembro de 2008

Benthic community structure and diversity have been investigated to assess stress conditions of Todos os Santos Bay, Bahia, Brazil, as a possible result of the extraction, transportation and re®ning of petroleum, activities carried out in this area for more than 40 years. Samples were collected over two years, at four stations under the direct in¯uence of stress-causing activities and at a control station. Benthic indices were calculated for all intertidal communities. The density, relative abundance, frequency of occurrence, diversity, similarity and occurrence of preferential species were recorded. Linear correlation indices were calculated to establish comparisons between ecological parameters of the studied communities and concentrations of heavy metals, hydrocarbons, petroleum pollution indicators and sediment mud percentages. The polychaete worms were the dominant group Ð up to 92% dominance in the community within the in¯uence of re®nery activities. Diversity indices indicated signi®cant stress related spatial gradients tied to petroleum. The re®nery sample station showed notable differences in its biodiversity ®gures compared to the other stations. Quantitative benthic indices showed negative correlations between the presence of cadmium, hydrocarbons, n-alkanes and the unresolved complex mixture in the intertidal zone marine sediments.

Liquid chromatography-inductively coupled plasma-mass spectrometry (LC-ICP-MS) was used for arsenic speciation analysis in tissues of bivalve mollusks (Anomalocardia brasiliana sp. and Macoma constricta sp.). Microwave and ultrasound radiation, combined with different extraction conditions (solvent, sample amount, time, and temperature), were evaluated for As-species extraction from the mollusks' tissues. Accuracy, extraction efficiency, and the stability of As species were evaluated by analyzing certified reference materials (DORM-2, dogfish muscle; BCR-627, tuna fish tissue; and SRM 1566b, oyster tissue) and analyte recovery tests. The best conditions were found to be microwave-assisted extraction using 200 mg of samples and water at 80°C for 6 min. The agreement of As-species concentration in samples ranged from 97% to 102%. Arsenobetaine (AsB) was the main species present in bivalve mollusk tissues, while monomethylarsonic acid (MMA) and arsenate (As(V)) were below the limit of quantification (0.001 and 0.003 μg g −1 , respectively). Two unidentified As species also were detected and quantified. The sum of the As-species concentration was in agreement (90 to 104%), with the total As content determined by ICP-MS after sample digestion.

Abstract-Although oil activities generate numerous forms of environmental impact on biological communities, studies of these impacts on Brazilian coastal ecosystems are rare. Results of tests for the content of oil in sediments and organisms indicate a substantially high rate of degradation. Results for uptake of polycyclic aromatic hydrocarbons in bivalves suggested the recent occurrence of oil spills and that these organisms differed in their capabilities to bioconcentrate oil. The mangrove community has suffered constant inputs of oil and has responded with increased numbers of aerial roots, generation of malformed leaves and fruits by plants, and a decrease in litter production. Studies of the impact of oil on rocky shore communities and the toxicity of oil and its by-products to marine organisms have confirmed the results reported in the literature. Presently most of the available studies deal with the macroscopic effects of oil on organisms and have indicated that the nature of oil, climate characteristics, the physical environment, and the structure of the community influence the symptoms of oil contamination in organisms of coastal waters. Longterm studies should be carried out to assess changes in community structure, sublethal effects in populations, and the resilience of contaminated ecosystems.

Este estudo teve como objetivos descrever o ciclo gametogênico e o comportamento reprodutivo da população de Iphigenia brasiliana (Lamarck,1818) no estuário do rio Subaé, Baía de Todos os Santos, Bahia. Os bivalves foram coletados de novembro de 2001 a novembro de 2002. Um total de 244 espécimes foi medido (eixo anteroposterior), eviscerado, fixado, desidratado e incluído em parafina. O estudo histológico das gônadas foi realizado através de cortes seriados do tecido gonadal, de 5 mm de espessura, e corados pela HE. O tamanho médio mínimo da primeira maturação sexual (Lpm) foi estimado a partir da distribuição das frequências relativas de jovens e adultos, por classe de comprimento dos indivíduos. As frequências relativas dos sexos em cada estádio de desenvolvimento foram consideradas conjuntamente para a análise do comportamento reprodutivo da população, e, em separado, para avaliar a sincronia do ciclo sexual entre machos e fêmeas. Foi observada uma variação de tamanhos entre 9,1 e 66,6 mm, com comprimento médio de 50,2 mm. O estudo não demonstrou diferença significativa entre os tamanhos de machos e fêmeas. Não foi possível observar a diferenciação de sexos em 2,1% dos indivíduos analisados. 51,6% dos indivíduos foram identificados como machos (M) e 46,3% como fêmeas (F), não sendo constatadas diferenças significativas entre o número médio de machos e fêmeas, resultando numa proporção de M:F de 1,1:1. O Lpm foi estimado em 11,4 mm, mas apenas ao alcançarem comprimento médio de 34,4 mm, todos os indivíduos foram considerados adultos. Foram caracterizados quatro estádios de evolução do desenvolvimento gonadal em fêmeas e machos. A análise dos diferentes estádios permitiu a observação dos fenômenos de atresia e inversão sexual em fêmeas. O ciclo reprodutivo apresentou eliminação contínua de gametas, com maiores intensidades reprodutivas nos meses de novembro de 2001 a abril de 2002 e, também, no mês de outubro de 2002.