979 resultados para the Jiaozhou Bay sediments


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The goal of this work was to establish comparisons among environmental degradation in different areas from Southern Spain (Gulf of Cadiz) and Brazil (Santos and Sao Vicente estuary), by using principal component analyses (PCA) to integrate sediment toxicity (amphipods mortality) and chemical-physical data (Zn, Cd, Pb; Cu, Ni, Co, V, PCBs, PAHs concentrations, OC and fines contents). The results of PCA extraction of Spanish data showed that Bay of Cadiz, CA-1 did not present contamination or degradation; CA-2 exhibited contamination by PCBs, however it was not related to the amphipods mortality. Ria of Huelva was the most impacted site, showing contamination caused principally by hydrocarbons, in HV-1 and HV-2, but heavy metals were also important contaminants at HV-1, HV-2 and HV-3. Algeciras Bay was considered as not degraded in GR-3 and -4, but in GR-3' high contamination by PAHs was found. In the Brazilian area, the most degraded sediments were found in the stations situated at the inner parts of the estuary (SSV-2, SSV-3, and SSV-4), followed by SSV-6, which is close to the Submarine Sewage Outfall of Santos - SSOS. Sediments from SSV-1 and SSV-5 did not present chemical contamination, organic contamination or significant amphipod mortality. The results, of this investigation showed that both countries present environmental degradation related to PAHs: in Spain, at Ria of Huelva and Gudarranque river's estuary areas; and in Brasil, in the internal portion of the Santos and Sao Vicente estuary. The same situation is found for heavy metals, since all of the identified metals are related to toxicity in the studied areas, with few exceptions (V for both Brazil and Spain, and Cd and Co for Brazilian areas). The contamination by PCBs is more serious for Santos and Sao Vicente estuary than for the investigated areas in Gulf of Cadiz, where such compound did not relate to the toxicity. (c) 2006 Elsevier Ltd. All rights reserved.

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The external infestation of Callinectes ornatus Ordway, 1863 and Callinectes danae Smith, 1869, in particular cirripeds, was studied for two consecutive years in the Ubatuba Bay (SP) (23 degrees 26' S and 45 degrees 02' W). Bryozoans, polychaetes and cirripeds were found on both swimming crab species, but cirripeds were the most abundant and frequent. The number of infested swimming crabs increased proportionally to carapace size, but not surpassing 30 %, suggesting an absence of terminal anecdysis in both species. The establishment of the pernicious organisms on their hosts is influenced by other factors, such as their habit of burying themselves in sediments. The correlation between molting activity in adult specimens of both sexes and the low incidence of epizoonts suggest that C. ornatus and C. danae may be molting after maturity.

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This work aims to analyse the composition, abundance and distribution of the Penaeidea species which occur in the Ubatuba Bay (23 degrees 26'S and 45 degrees 02'W). The samples were monthly collected from October/1992 to September/1993. Each collect was composed of two parallel radials: the first (radial ''A'') was carried out in the mid region of the bay and the second one (radial ''B'') in the bay mouth. The trawls took one hour in a boat equipped with one otter-trawl (10 mm of mesh). The registered environmental factors were depth, bottom water temperature, granulometric composition and organic content of the sediment. After the trawls, the shrimp were separated from other marine organisms and counted. Eight species of shrimp were obtained: Xiphopenaeus kroyeri; Artemesia longinaris; Penaeus (L.) schmitti; P. (F.) brasiliensis; Trachypenaeus; constrictus; Sicyonia typica; S. dorsalis and Pleoticus muelleri. The most abundant species were X. kroyeri, A. longinaris, P. muelleri and T. constrictus. It was verified a very strong seasonality among the species. The X. kroyeri species occurred in both radials along the months but its abundance decreased from a November to March. Such fact is attributed to the temperature which reached a minimum value of 20 degrees C during this period. The species A. longinaris and P. muelleri were more frequent in the radial B which was caracterized by 14 +/- 1.3 m of depth, low organic content in the sediment (2.97%) and granulometric composition of medium sand. The distribution and abundance of these shrimps in the bay, beyond the hydrological features can be related to biotic factors as food availability, migration, inter and intra specific relations (competition, predation, etc.).

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The objective of the present study was to characterize the spatial distribution and shell utilization of three hermit crab species in the estuarine-bay complex of São Vicente, São Paulo State, Brazil. Monthly samples were done throughout two years, in the non-consolidated sub-littoral at the estuarine-bay complex. The environmental factors, such as temperature, salinity and depth, were measured every month. The three hermit crab species, Clibanarius vittatus, Loxopagurus loxochelis and Isocheles sawayai, were captured utilizing shells from six gastropods species; 92.7% of the hermit crabs utilized Stramonita haemastoma. The results suggest a strong correlation between hermit crabs spatial distribution and salinity, which was considered the main environmental factor limiting their distribution in the estuary. I. sawayai was the only species present in all transects sampled; C. vittatus was captured only in regions with low salinity and L. loxochelis occurred only in high salinity waters.

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Purpose: The purpose of this paper is to study the interactions of sedimentary humic substances (SHS) from a sugarcane cultivation area with Cu(II) and Cr(III) and to evaluate the occurrence of these metals in the pore water and SHS. Materials and methods: For this study, the northwestern region of the State of São Paulo, Brazil, which is considered the region with the highest production of sugar cane in the state, was selected. Samples of sediment were collected from four sampling sites in the Preto, Turvo, and Grande rivers. The SHS and pore water were extracted from the sediment using the method suggested by the International Humic Substances Society and centrifugation, respectively. The complexing capacity (CC) of the SHS for Cu(II) and Cr(III) was determined by individually titrating these metals with an ultrafiltration system using tangential flow. The total concentrations of Cr and Cu were determined for the pore water, sediments, and humic substances with graphite furnace atomic absorption spectrometry and Zeeman background correction after an acid digestion, according to the methods described in US EPA Method 3050B. Results and discussion: The SHS from a site in the Turvo River, which is typically cultivated with sugarcane, possessed the highest concentration of Cu bound to SHS (25.0%), the largest CC (0.63 mmol Cu g-1 HS) and the highest concentration of this metal in the pore water (1.38 mg Cu Kg-1 sed.). For Cr, the SHS collected from a location on the Preto River dam had the largest CC (0.90 mmol Cr g-1 HS) and the lowest Cr content in the pore water (0.29 mg Cr Kg-1 sed.), indicating that there was an inverse relationship between the CC and the concentration of metal available in the pore water. Conclusions: Sedimentary humic substances might be one of the regulatory factors controlling the availability of Cu and Cr in the sediments found in a typical region that has been planted with sugarcane. Distinct behaviors were observed between the two elements investigated; higher CC and a larger fraction of Cu(II) were found in the pore water of samples originating from sugarcane crops. The opposite behavior was observed for the Cr(III) species. © 2013 Springer-Verlag Berlin Heidelberg.

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Os sedimentos do lago Coari, de ambiente de terra firme esculpido nos depósitos do Plio-Pleistocenos, e o Acará, típico lago de várzea e ambos formados nos sedimentos quaternários da planície de inundação do médio Solimões, no oeste da Amazônia, Brasil, foram estudados para investigar as condições ambientais durante sua formação. Este estudo inclui dados da composição mineralógica, química, isótopos de Pb, palinologia, datações de radiocarbono e a configuração morfológica dos lagos obtida por imagens SRTM. As condições geológica e ambiental dos lagos variam e sugerem que suas evoluções refletem processos autogenéticos em condições de floresta úmida e chuvosa. Embora caulinita, quartz, muscovita, illita e esmectita sejam os principais minerais em ambos os lagos, a geoquímica indica fonte distinta, os sedimentos do lago Acará têm maior concentração de Al2O3, Fe2O3, FeO, CaO, K2O, MgO, Na2O, P2O5, Ba, V, Cu, Ni, Zn, Pb, Sr, Li, Y e La e têm mais Pb radiogênico que os sedimentos do lago Coari. As idades de radiocarbono sugerem que há aproximadamente 10160 anos AP o lago Coari iniciou o desenvolvimento devido a avulsão do rio Solimões, enquanto o lago Acará foi formado devido ao abandono de meandro do rio Solimões e retendo o domínio das gramíneas nas suas praias há aproximadamente 3710 anos AP.

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ABSTRACT: Lead analyses in bottom sediments from the hydrographic system of Belem (Para) indicated low contents of this metal for the sediments from the Guama river, with no significant anthropogenic contribution. A concentration of 18.1 ± 1.5 mg kg-1 and 206Pb/207Pb isotopic signature of 1.196 ± 0.002 are assigned for Pb from natural sources. On the other hand, the significant increase of Pb contents in the sediments from the Guajará bay, together with the decrease of 206Pb/207 ratios (1.172 < 206Pb/207 < 1.188) point to an anthropogenic lead contribution, originated by the industrial and urban activities of the city of Belem.

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ABSTRACT: The present study focused on the decapod fauna of the fluvial-estuarine environment of the Guajará Bay, in the Brazilian state of Pará, where specimens were collected monthly from six sites, from May 2006 to April 2007. A total of 6,793 specimens were captured, belonging to 11 species of crab and shrimp: eight palaemonids - Macrobrachium amazonicum (Heller, 1862), Macrobrachium surinamicum Holthuis, 1948, Macrobrachium carcinus (Linnaeus, 1758), Macrobrachium rosenbergii (De Man, 1879), Macrobrachium spp. 1-4 -, one portunid - Callinectes bocourti A. Milne-Edwards, 1879 -, and two trichodactylids - Sylviocarcinus devileii H. Milne-Edwards, 1853 and Sylviocarcinus pictus (Milne-Edwards, 1853). While no significant differences were found in the ecological indices of diversity with respect to season, site, or trap size, a tendency for increased abundance and species richness was found during the dry season (August-November), in particular at some sites, apparently reflecting the influence of the estuary's saline wedge.

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ABSTRACT: The thalassinideans (Axiidea and Gebiidea) encompasses approximately 615 species with reclusive habits, generally confined to extensive galleries burrowed into the sand or mud and, more rarely, in openings in reefs or the cavities of sessile animals such as sponges and coral. These species use the galleries for shelter, feeding and breeding, except during the pelagic larval stage. They inhabit estuaries, bays, lagoons, beaches, seas and both tropical and temperate oceanic areas throughout the world, distributed predominantly in the intertidal zone (mid-littoral and infralittoral zones). The aim of the present study was to assess the species composition and abundance of thalassinideans, comparing two micro-habitats (consolidated and non-consolidated substrates), and determine whether there is a correlation between abundance of the organisms and time of the year, collection sites or salinity. Twelve monthly samplings were carried out between August 2006 and July 2007 over consolidated and non-consolidated bottoms of the upper and lower portions of the mid-littoral zones, with three sub-samplings, totaling 48 monthly samples and 576 in all. A total of 651 individuals were collected – 114 Lepidophthalmus siriboia Felder & Rodrigues, 1993 and 537 Upogebia vasquezi Ngoc-Ho, 1989. There was correlation between the abundance of both species and salinity, but U. vasquezi was more abundant in the rainy season. Lepidophthalmus siriboia appears to prefer non-consolidated substrates, whereas U. vasquezi prefers consolidated substrates. The recruitment period for the callianassid L. siriboia appears to occur in just two periods of the year and is more intense in the dry season, whereas U. vasquezi is more frequent throughout the year. The smallest and largest sizes (carapace length – CL) recorded for L. siriboia were smaller than those recorded for the species in northeastern region of Brazil. CL values for ovigerous females suggest that U. vasquezi reaches sexual maturity at a smaller size than L. siriboia.

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Na zona costeira, sedimentos, água e organismos interagem intensamente. Nas costas equatoriais dominadas por maré os manguezais são abundantes. Estas áreas são conhecidas por sua importância ecológica. No caso dos manguezais da costa atlântica da América do Sul o caranguejo-uçá Ucides cordatus (Linnaeus, 1763) se destaca por sua relevância ecológica e econômica, sendo que altas densidades deste organismo são encontradas na zona costeira amazônica. O presente estudo investiga a distribuição de sedimentos nos manguezais de Bragança (costa Amazônica, Brasil) e suas correlações com a vegetação e a distribuição do caranguejo-uçá. Quarenta e sete amostras de sedimento foram avaliadas, assim como caranguejos de 8 destas áreas foram coletados, onde o tipo dominante de vegetação foi também identificado. Os resultados demonstram que os sedimentos superficiais, assim como no extrato 0,8 a 1 m de profundidade, na área são principalmente compostos por silte (59%), incluindo em média 21% de areia e 20% de argila. O tipo de vegetação predominante foi significativamente correlacionado com a abundância e tamanho/peso dos caranguejos. As características sedimentares também foram substancialmente diferentes dependendo da vegetação. Áreas dominadas por Avicennia germinans tiveram mais areia e argila que as áreas dominadas por Rizophora mangle, onde a fração silte prevalece grandemente e os caranguejos eram significativamente maiores e mais abundantes. Os resultados demonstraram que sedimentos, invertebrados bentônicos e vegetação estão intimamente relacionados nos manguezais e devem ser estudados de maneira integrada.

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Dados meteorológicos e simulações numéricas de alta resolução foram usados para estimar campos espaciais na região leste da Amazônia onde se situam a Floresta e a Baía de Caxiuanã, no Estado do Pará. O estudo foi feito para o período de Novembro de 2006, quando foi realizado o experimento de campo COBRA-PARÁ. Análises de imagens do sensor MODIS mostram a ocorrência de vários fenômenos locais como avenidas de nuvens, sistemas convectivos precipitantes, e importante influência das interfaces entre a floresta e as superfícies aquáticas. Simulações numéricas para o dia 7 de novembro de 2006 mostraram que o modelo representou bem as principais variáveis meteorológicas. Os resultados mostram que a Baía de Caxiuanã provoca importante impacto nos campos meteorológicos adjacentes, principalmente, através da advecção pelos ventos de nordeste que induzem a temperaturas do dossel mais frias a oeste da baía. Simulações de alta resolução (LES) produziram padrões espaciais de temperatura e umidade alinhados com os ventos durante o período diurno e mudanças noturnas causadas principalmente pela presença da baía e chuvas convectivas. Correlações espaciais entre os ventos de níveis médios e os fluxos verticais de calor latente mostraram que existe uma mudança de correlações negativas para as primeiras horas do dia passando para correlações positivas para o período da tarde e início da noite.

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Os Hidrocarbonetos Policíclicos Aromáticos (HPAs) são poluentes de efeito tóxico, prejudiciais ao meio ambiente e à saúde humana, fazem parte de um grupo de compostos poluentes orgânicos persistentes (POPs), que por suas características tem impactado o ambiente, sendo por esse motivo bastante estudados. Podem estar presentes nas formas particulada, dissolvida e/ou gasosa, estando presentes em diferentes ambientes; solo, sedimento, ar, água, material particulado na atmosfera, organismos e alimentos (Kennish, 2007). As fontes naturais de HPAs incluem atividades vulcânicas, queimadas naturais, exsudação de óleos, além de processos biogênicos. HPAs antrogênicos podem ocorrer pela combustão incompleta de óleos combustíveis (automotores e industriais), queima intencional de madeira e plantações, efluentes domésticos e/ou industriais, drenagens pluviais urbanas, derrames acidentais de óleos e derivados. Hidrofóbicos e lipofílicos, essas substâncias podem ser facilmente adsorvidas em sedimentos, sendo este compartimento um importante reservatório desses poluentes. Para avaliar a presença desses compostos no ambiente, utilizou-se nesse trabalho a Cromatografia Líquida de Alta Eficiência. As amostras utilizadas no desenvolvimento e otimização da metodologia foram coletadas na baia do Guajará (Belém – PA). O presente trabalho constituiu-se dessa forma em um desenvolvimento de um procedimento metodológico (com adaptações e otimizações) para quantificar 16 HPAs em 10 pontos na baia do Guajará, Belém – PA, em duas etapas de campo, totalizando 20 amostras analisadas. Na etapa de desenvolvimento do método analítico foram testados sistemas de eluição, polaridade do sistema e fluxo do eluente entre outros. Para validação do método foram avaliados os parâmetros fidelidade, linearidade, limite de detecção, limite de quantificação do método. Razões diagnósticas foram calculadas para identificação das fontes primárias do HPAs encontrados na baia. Foram identificadas, a partir de razões diagnósticas da ΣHPAs BMM/ΣHPAsAMM; Fen/Ant; Flt/Pir; Ant/Σ178; Flt/Σ202; B(a)P/Σ228 e Ind(123cd) pireno/Σ276 as fontes primárias dos 16 HPAs estudados no sedimento da baia. A somatória das concentrações dos HPAs leves na primeira etapa de campo, variou de 132,13 ng.g-1 a 1704,14 ng.g-1, a ΣHPAs dos pesados de 125,82 g.g-1 a 1269,71 ng.g-1 e ΣHPAs totais de 317,84 ng.g-1 a 3117,06 ng.g-1.. Na segunda etapa de campo, as concentrações dos HPAs leves variou de 76,12 ng.g-1 a 1572,80 ng.g-1 ; a ΣHPAs pesados variou entre 213,90 ng.g-1 a 1423,03 ng.g-1, e Σ HPAs totais teve concentrações de 290,02 ng.g-1 a 2995,82 ng.g-1. A partir dos resultados obtidos pode-se classificar a baia do Guajará como moderadamente impactada. A combustão constitui a fonte predominante de HPAs nos sedimentos da baia do Guajará, seguida da combustão de biomassa vegetal e aporte de petróleo e derivados. A maioria dos pontos estudados nesse trabalho, nas duas etapas de campo, apresentaram concentrações de HPAs individuais acima dos VGQS.

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ABSTRACT: In Guajará bay, mouth of the Amazon River, is located the capital of Pará state (Belém) and its metropolitan area. Exists in this area an intense boat traffic, as well as transportation and sale of fuels in floating docks and activities related to the storage and transportation of oil in Miramar Petrochemical Terminal (TEMIR). Small spills and discharges of oil in water can serve as sources of pollution by polycyclic aromatic hydrocarbons (PAHs). PAHs are organic compounds generated by incomplete combustion of organic matter (OM) and are among the contaminants of most interest in environmental studies due to their mutagenic and carcinogenic potential. One way to detect and evaluate the impact of PAHs in an environment is using biomonitors, however the qualitative and quantitative analysis in sediments are most widely used. This study aimed to evaluate, by Gas Chromatography/Mass Spectrometry (GC/MS), the 16 PAHs considered as priority by the Environmental Protection Agency of the United States in sediments and benthic organisms (Namalicastys abiuma) of TEMIR. Field expeditions were carried out in December 2012, March, May and June 2013 representing the dried, wet (two samples) and dried seasons successively. Fine sediments levels dominated in both sampling periods and the %Fines in Guajará bays has a direct relationship to the %OM. In relation to the 16 PAHs studied, 10 of them were detected in the wet season sediments samples and 8 in the dried season. Even with a low diversity of aromatic compounds, sediment samples of the dried season presented greater ΣHPAs (1.351,43 ng g-1) than the sediments of the wet season (263,99 ng g-1), which can be related to the increased hydrodynamic in Guajará bay this last period. Correlation analysis indicated that ΣHPAs not seem to be influenced by %Fine and %OM. Benzo(a)pyrene accounted for 87% of ΣHPAs during the wet season, the other PAHs showed percentage ≤ 3%. During the other period stood out: pyrene (18% of ΣHPAs) fluoranthene (16%), the chrysene, benzo(b)fluoranthene (15%) and benzo(a)pyrene (11%). The use of the geochemical reason to interpret likely sources of PAHs indicated that there is a predominance of aromatics from pyrolytic origin in TEMIR. The activities that may be responsible for the PAHs levels observed in sediments and benthic organisms in TEMIR are the discharge of untreated domestic sewage and the emissions of particulates from cars and small/medium boats. The ΣHPAs seems to influence the density of polychaetes because a reduction of about 50% in the number of organisms was observed during the dry season when there was the greater amount of ΣHPAs in their body structure. Among the 16 PAHs studied, 11 were detected in the polychaetes during the dry season (ΣHPAsMED = 848,71 ng g-1) and 10 in the wet season (ΣHPAsMED = 141,85 ng g-1). Were highlighted during the dried season: indeno(1,2,3-c,d)pyrene (47%) and pyrene (23%). While in the wet season: pyrene (23%), chrysene (17%), fluorene (17%) and fluoranthene (13%). The %Rec obtained was >>100% indicating a matrix effect and reducing the quantitative accuracy of results. The use of the polychaete N. abiuma as biomonitor of pollution by PAHs in estuaries not seem to be effective when the sample period is limited, because collecting it requires a great effort to obtain a small amount of mass and it still results in a matrix effect in the chromatographic analysis (method %Rec >> 100%) that may not be corrected due to the restricted availability of sample mass. Studies with a larger number of samples, enabling depth statistical analysis, and covering other collection points in Guajará bay are required to prove mathematically that has been stated in this dissertation.

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O presente estudo descreve a estrutura espacial e temporal da comunidade de peixes estuarinos da porção interna do estuário Amazônico. Amostras foram obtidas no canal principal e canais de maré das Baías do Guajará e Marajó e rio Guamá. Foram coletados um total de 41.516 espécimes, correspondendo 136 espécies, 38 famílias e 12 ordens. Na estação seca, a salinidade média no canal principal aumentou ao longo do gradiente limnico–marinho, entre o rio Guamá e a Baía do Marajó. A riqueza de espécies foi mais baixa na foz do rio Guamá e na margem direita da baía do Guajará. A composição das espécies e as guildas ambientais diferiram significativamente entre as áreas: Migrantes e Ocasionais de água doce foram dominantes no rio Guamá e na Baía do Guajará, enquanto Estuarinas, Marinhas Migrantes e Ocasionais dominaram na Baía do Marajó. Contudo, as guildas tróficas foram relativamente bem balanceadas, em termos funcionais. Piscívoros e Zoobentívoros foram os grupos alimentares dominantes em todas as áreas. Neste estudo, a avaliação da comunidade e o uso da abordagem com guildas foram eficientes para descrever a estrutura e o funcionamento das assembleias de peixes estuarinos e também como ferramenta na avaliação das pressões antrópicas na área.