Christiano Magini

Using bioassays and benthic community to evaluate the sediment quality at the estuary of Itanhaém river, SP, Brazil

This work aimed to assess the quality of sediments from the estuary of the Itanhaém River using whole sediment toxicity tests with the burrowing amphipod Tiburonella viscana; and the analysis of the benthic community. Results showed that the sediments are preponderantly sandy, with low or absence of toxicity to T. viscana. The benthic community was poor, composed mainly by opportunistic organisms, including capitelid polychaetes. Its structure was mainly controlled by the environmental variables, as sediment grain size and water properties, but some influence of the toxicity was also observed. The quality of the sediments from the estuary ranged from moderate to good. KeywordS: Estuaries. Geologic sediments. Toxicity tests. reSUmo: Esta investigação teve como objetivo avaliar a qualidade de sedimentos do estuário do Rio Itanhaém, utilizando teste de toxicidade de sedimento integral com anfípodo escavador Tiburonella viscana e análise da comunidade bentônica. Os resultados mostraram que os sedimentos são principalmente arenosos, com baixa ou nenhuma toxicidade sobre T. viscana. A comunidade bentônica foi composta principalmente por organismos oportunistas, incluindo poliquetos capitelídeos, tendo sido considerada pobre. Sua estrutura foi controlada principalmente pelas variáveis ambientais, como a granulometria e as propriedades físico-químicas da água, porém uma leve participação da toxicidade pôde ser detectada. A qualidade dos sedimentos do estuário variou entre moderada e boa. PALAvrAS-chAve: Estuários. Sedimentos geológicos. Testes de toxicidade. reSUmen: Este trabajo pretendió evaluar la calidad de sedimentos del estuario del Río Itanhaém usando pruebas de toxicidad de sedimento integral con anfípodo escavador Tiburonella viscana y el análisis de la comunidad bentónica. Los resultados mostraron que los sedimentos son preponderantemente arenosos, con baja o ninguna toxicidad para T. viscana. La comunidad béntica era pobre, formada principalmente por organismos oportunistas, incluso poliquetos capitelídeos. Su estructura fue controlada principalmente por las variables ambientales, como lo son el tamaño de los granos de sedimento y propiedades del agua, pero un poco de influencia de la toxicidad también fue observado. La calidad de los sedimentos del estuario varió de moderado a bueno. PALAbrAS LLAve: Estuários. Sedimentos geológicos. Pruebas de toxicidad. * Graduado em Ciências Biológicas. Especialista em Engenharia de Controle da Poluição pela Faculdade de Saúde Pública da USP e Pesquisador colaborador da Universidade Estadual Paulista – UNESP – Campus do Litoral Paulista. E-mail: robsonseriani@yahoo.com.br ** Biólogo. Mestre e Doutor em Oceanografia pelo Instituto Oceanográfico da USP. Professor da UNESP – Campus do Litoral Paulista. *** Graduada em Ciências Biológicas. **** Graduada em Ciências Biológicas. Especialista em Saúde Ambiental pela Faculdade de Saúde Pública da USP. ***** Geólogo. Mestre e Doutor em Geologia Regional da Unesp. Professor da Universidade Federal do Ceará. Introduction The coastal ecosystems, particularly the estuaries, present high ecological and economic importance, offering products and services to the humans. However, due to their geographic characteristics, estuaries have been occupied by urban structures, industrial facilities, ports and harbors, among others. In Brazil, such occupation has been made disorderedly, resulting in degradation to the estuarine and associated ecosystems. According to Clark (1997), the discharge of pollutants into the coastal waters is directly related to using Bioassays and Benthic community to evaLuate the sediment QuaLity at the estuary of itanhaém river, sp, BraziL O MundO da Saúde São Paulo: 2008: jul/set 32(3):294-301 295 the land occupation. Once in the aquatic environment, the chemicals tend to sink to the bottom, accumulating in the sediments, where they can be transformed by a variety of physical, chemical and biological processes, which can make them to be released back to the water column. Thus, sediments can be not only a reservoir but also a source of contamination to the aquatic biota (Burton, 1992). The biological effects of pollutants are diverse, and may vary from biochemical and genetic disturbance to ecological unbalance (Reish, 1986). Besides, the damage of aquatic populations can threat the economic exploration of biological resources, bringing negative effects to the economy and the human health. The environmental quality can be evaluated by different approaches, as by chemical as by biological perspectives. Toxicity tests and analyses of the structure of biological communities are used to evaluate the environmental quality, once they are inexpensive and show the effects of the whole complex mixture of contaminants to the organisms (Chapman, Long, 1983; Bilyard, 1987). The Itanhaém River is located on the central shore of the State of São Paulo, Brazil (23°50’-24°15’S, 46°35’00”W) and presents high social, economic and ecological importance. Its hydrographic basin is considered the second larger coastal basin in the State of São Paulo (Sant’Anna, 1999). The Itanhaém River is surrounded by wide mangroves, supporting regional fishing and tourist activities and providing shelter and food for aquatic and terrestrial species (Souza-Pereira, Camargo, 2004). The lower portion of Itanhaém River and its estuary are influenced by anthropogenic activities, especially the discharge of untreated sewage from the Itanhaém City urban area (Pereira, 2002). The presence of irregular dumping sites of urban residues in the vicinities constitutes other contamination sources. Chronic sediment toxicity and bioaccumulation of Arsenic (As) in tissues of crabs were already found in Itanhaém river (Carmo et al, 2004). Recently, toxicity in sediments from two sites of this river (Seriani, Silveira, 2005; Seriani, et al, 2006) was observed. Other studies have also correlated the pollution to physical-chemical alterations in the water (Abessa et al, 2006; Camargo, et al, 1996) and in the biological communities (Choueri, 2000). The objective of this study was to evaluate the environmental quality of the estuary of the Itanhaém River, by using 10-day whole sediment toxicity tests with the burrowing amphipod Tiburonella viscana and analyses of the benthic community structure. materials and methods The sediments samples were collected with a “Van Veen” grab sampler at six stations situated in the estuary of the Itanhaém River (Figure 1). The samples for physical and ecotoxicological analyses were immediately cooled. In laboratory, the aliquots for the toxicity tests were refrigerated, whereas those for physical-chemical analyses were frozen. Independent samples were taken for the benthos and sieved by a 0.5 mm mesh. The retained organisms were identified under microscope till the minimum possible level accordin Amaral et al, (2006). The dataset was used to calculate the Specific Richness (S); Total Organisms Density; Shannon-Wiever Diversity (H’); Simpson Dominance (J); and Polychaetes Dominance according Abessa (2002), Abel (1989) apud Seriani et al (2005). Water column samples were collected for the analysis of physical chemical parameters (APHA, 2005). The water temperature was measured by a digital thermometer; the pH was determined by a digital pHmeter; and the salinity was obtained by the use of a hand refractometer. The total ammonia concentration (NH3-NH4) was measured by colorimetric method (Koroleff, 1970). The sediment grain size distribution was measured by the dry sieving method (Suguio, 1973). The calcium carbonate content was analyzed by the difference of weights, before and after digestion in 10% HCl (Gross, 1971). The Organic Matter (OM) content was estimated by weight difference before and after incineration at 600°C for 90 minutes. The 10-day whole sediment toxicity test was conducted following the method described by Melo, Abessa (2002) for Tiburonella viscana. The test-organisms and the control sediment were collected at Engenho d’Água Beach, in Ilha Bela Island. The environmental, physicalchemical, ecotoxicological and ecological data were integrated by several methods. Multiple Pearson correlations were calculated for the ecological indices X variable ecotoxicological data and sediment characteristics. Variables for which correlation coefficients (r) were above |0.4|, when p<0.05, were considered significantly correlated. Another method used to relate the biotic and abiotic data was the Canonic Ordination Analysis, coupled with the Monte Carlo test (Abessa, 2002).

Lateritas do Domínio Médio Coreaú - comportamento geoquímico de mantos lateríticos do Noroeste do Estado do Ceará

In this paper an evaluation is made over the geochemistry signature of major elements in lateritic rocks on the counties of Granja, Martinopole and Parazinho, Northwest of Ceara State. Geologically, the area is located in Medio Coreau Domain, characterized by the Granja Complex, which is the geological basement of the region, composed by gneiss, granulites and migmatites, and supracrustal sequences formed by quartizites and phyllites of Martinopole and Ubajara Group, and also cenozoic sediments of Barreiras Formation. Laterites are normally found in humid weather (seasonal or not), so it is more likely that the generation process of this lateritic beds were under ancient climatic conditions, totally different from the present. The laterites are associated with gneiss, quartzites and phyllites. The prevailing laterization process is the metal enrichment, especially iron. Iron content varies from 34.69 to 77.85% in the altered rock samples; this trend being more evident in gneiss, in which iron enrichment exceeds 75%. Al content increases 6 to 7% in altered rocks. Sm-Nd data showed that the ratios obtained in these laterites are similar to the protoliths and can be used to define autochthonous from allocththounus laterites and also confirm Sm and Nd mobility in the laterization process.

Sistema Sm-Nd em rocha-total aberto versus fechado: comportamento isotópico em zonas de alta deformação

High strain shear zones of Brasiliano age, developed in Paleoproterozoic basement gneiss of the Caico region, Borborema Province, NE Brazil, were associated with medium- to low-grade metamorphism and deformational processes that transformed porphyritic augen gneiss into muscovite quartzite, modifying their original mineralogy and chemical properties. During the last hydrothermal event mobility of major, minor and trace elements was great, whereas the pattern of Rare Earth Elements was not changed. We carried out a Sm-Nd isotopic study in these rocks in order to understand the behavior of Nd isotopes during mylonite generation. T DM model ages at around 2.6 Ga and µNd (t) values for both protolith and transformed rock suggest that the Nd isotopic system remained closed, recording the original source rock signature, despite undergoing two superposed metamorphic events.These new Sm-Nd results provide important information on the geologic evolution of basement rocks in the central Rio Grande do Norte Terrane of the Borborema Province, NE Brazil.