Physical, chemical and microbiological characterization of the intertidal sediments of Pereque Beach, Guaruja (SP), Brazil

Physical and chemical characteristics of intertidal sediments and their relationships with bacteria and cyanobacteria, were analyzed at four stations at Pereque Beach. Granulometric analysis showed that Pereque beach has sediment that is classified as sand. The lowest value of the sediment C/N rates (6.08), mainly due to a higher concentration of organic nitrogen, was found at the northern part of Pereque Beach, where organic matter of marine source was more prominent. In this area, density (9.6 x 106 cells cm(-3)), biomass (1992.04 ngC cm(-3)) and activity of bacteria were higher than at the southern end. In contrast, cyanobacteria density varied from 2.0 to 4.0 x 10(5) cells cm(-3), with biomass and total chlorophyll a of the sediment being higher at the southern part, where there are water input from Pereque River and higher organic matter of continental origin. The variability in the microbial population is discussed in the light of the sediment granulometry, organic matter quality, fresh water inflow and pollution. (c) 2007 Elsevier Ltd. All rights reserved.

Hematology of free-living marsh deer (Blastocerus dichotomus) from Southeast Brazil

This work reports basic hematologic values of a sample of a population of free-living marsh deer (Blastocerus dichotomus) living by the Parana River in Southeast Brazil. Hematologic values are presented separately for male, female, and young animals as well as for anesthetized and nonanesthetized cervids. Nonanesthetized deer restrained by physical means had significantly higher erythrocyte indices and total leukocyte counts. Comparisons of blood parameters of anesthetized animals of different ages and gender differed slightly, with only two significant differences observed: young animals had significantly higher red blood cell counts than adult males and a lower blood total protein content when compared to adult females. Results indicate that two main reference ranges for blood values should be considered for marsh deer, for blood obtained from anesthetized or physically restrained individuals.

Comparative sediment quality assessment in different littoral ecosystems from Spain (Gulf of Cadiz) and Brazil (Santos and Sao Vicente estuarine system)

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.

The role of organic matter on the adsorption of mercury in sediments from Amazon lakes, Brazil

Gold has been exploited intensively in the Brazilian Amazon during the past 20 years, and the elemental mercury (Hg) used in amalgamating the gold has caused abnormal Hg concentrations in waterways. Since 1986 particular attention has been given to the Madeira River because it is the largest tributary of the Amazon River and gold mining was officially allowed on a 350-km sector of the river. In this paper, samples of sediments from nine lakes located in the Madeira River basin, Rondonia State, Brazil, were analysed for mercury and organic matter. The average Hg content ranged between 33 and 157 ppb, which is about 8-40 times higher than the average value corresponding to 4.4 ppb for rocks occurring in the area (regional background). Significant correlation was found between the Hg content and organic matter in the sediments, indicating its importance on the retention of this heavy metal.

Use of U-isotope disequilibrium to evaluate the weathering rate and fertilizer-derived uranium in São Paulo state, Brazil

The U-disequilibrium method was utilized to evaluate the velocity of alteration of rocks and fertilizer-derived uranium in the Corumbatai River basin, São Paulo state, Brazil. The Corumbatai River basin is affected by the continuous use of fertilizer-derived uranium utilized in sugar cane crops, increasing the dissolved uranium concentration in the Corumbatai River (Santa Terezinha station) in the wet period to 43%. The weathering rate in the Corumbatai River basin utilizing the U-isotope modeling was 0.0265 mm/year (corresponding to 38,000 years to weather 1 m of rock under actual climatic conditions). However, when the inputs of anthropogenic uranium were considered, then a weathering rate of 0.022 mm/year (corresponding to 45,500 years to weather 1 m of rock) was determined. The removed material in the Corumbatai River basin is mainly from two sub-basins (the Cabecas River and Passa Cinco River), where the sandstones weather easier than the siltstones and claystones in the basin.

Determination of weathering rate of the Morro do Ferro Th-REEs deposit, Brazil using U-isotope method

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Well productivity controlling factors in crystalline terrains of southeastern Brazil

Over the last decades, increasing water demands have fostered research to obtain high well yields in crystalline terrains where, besides the intrinsic properties of rocks, the groundwater flow depends on several factors. The depth of the wells, the lithotypes, the presence and thickness of sedimentary coverings and weathered layers, the landforms, the geological structures, and the effects of tectonic stresses are among the most investigated factors considered as determinant of well productivity. The influence of these factors on productivity of wells that exploit the Crystalline Aquifer System in the Jundiai-River Catchment, southeastern Brazil, is investigated in this work. The largest region of the studied area is located on the Precambrian Basement, partially covered by sedimentary deposits. The results show that the sedimentary deposits and the weathered layer are important for high well yield, but it also depends on the existence of a net of open fractures, in order to maintain high productivity. The sites that have more possibility of occurrence of such structures are the regional shear and fault zones and other minor structures with NW-SE and E-W directions, which characterize areas subjected to transtensional stress related to the neotectonics.

Exotic species of freshwater decapod crustaceans in the state of São Paulo, Brazil: records and possible causes of their introduction

Based on recent surveys of the freshwater decapod fauna, distributional data of five exotic species of freshwater decapod crustaceans for the hydrographic basins of the state of São Paulo are presented, as part of a large initiative for a comprehensive survey of the state's biodiversity (BIOTA-FAPESP Program). These species are the North American crayfish Procambarus clarkii (Girard) (Cambaridae), the crab Dilocarcinus pagei Stimpson (Trichodactylidae) from the Amazon and Paraguay/lower Parana River Basins, and the palaemonid shrimps Macrobrachium rosenbergii (De Man), from the Indo-Pacific region, Macrobrachium amazonicum (Heller) and Macrobrachium jelskii (Miers), both from the Orinoco, Amazon and the Paraguay/lower Parana River Basins. Possible modes by which their introduction might have occurred are commented upon and potential consequences are discussed.

Reduction of mercury(II) by tropical river humic substances (Rio Negro) - Part II. Influence of structural features (molecular size, aromaticity, phenolic groups, organically bound sulfur)

The influence of structural features of tropical river humic substances (HS) on their capability to reduce mercury(II) in aqueous solutions was studied. The HS investigated were conventionally isolated from Rio Negro water-Amazonas State/Brazil by means of the collector XAD 8. In addition, the isolated HS were on-line fractionated by tangential-flow multistage ultrafiltration (nominal molecular-weight cut-offs: 100, 50, 30, 10, 5 kDa) and characterized by potentiometry and UV/VIS spectroscopy. The reduction of Hg(II) ions to elemental Hg by size-fractions of Rio Negro HS was assessed by cold-vapor AAS (CVAAS). UV/VIS spectrometry revealed that the fractions of high molecular-size (F-1 > 100 kDa and F-2: 50-100 kDa) have a higher aromaticity compared to the fractions of small molecular-size (F-5: 5-10 kDa, F-6: < 5 kDa). In contrast, the potentiometric study showed different concentration of functional groups in the studied HS fractions. The reduction of Hg(II) by aquatic HS fractions at pH 5 proceeded in two steps (I, II) of slow first order kinetics (t(1/2) of I: 160 min, t(1/2) of II: 300 min) weakly influenced by the molecular-size, in contrast to the differing degree of Hg(II) reduction (F-5 > F-2 > > F-1 > F-3 > F-4 > > F-6). Accordingly, Hg(II) ions were preferably reduced by HS molecules having a relatively high ratio of phenolic/carboxylic groups and a small concentration of sulfur. From these results a complex 'competition' between reduction and complexation of mercury(II) by aquatic HS occurring in tropical rivers such as the Rio Negro can be suggested. (C) 2003 Elsevier B.V. All rights reserved.

Distribution of Neohelice granulata (Dana 1851) in its northernmost latitudinal occurrence in a tropical mangrove forest, Brazil (Crustacea, Decapoda, Brachyura, Grapsoidea, Varunidae).

Neohelice granulata ecological distribution was evaluated in its northernmost latitudinal occurrence in a Brazilian tropical mangrove (23[degree]13'4" S, 44[degree]42'47" W). Samples were collected in three sites along the main river in the mangrove. Crabs were manually captured by two people, 15 min each, at low tide periods. The sex of the animals was assessed and carapace width measured. The size-frequency distribution was determined in each site. Environmental factors (salinity, temperature, organic matter and sediment texture) were analyzed, compared among sites and related to crab abundance and size in each site. Crab abundance decreased with the distance from the sea. Juvenile crabs were more frequent next to the sea, whereas larger and ovigerous ones were mainly found in the most distant site. Crab size was proportional to the organic matter percentage in the sediment. N. granulata spatial distribution varies along the river course, which is probably related to the most productive areas that have more nutrients available; this may also occur in order to prevent intraspecific competition.

A QUANTITATIVE APPROACH TO SUBSIDIZE THE PRECAUTIONARY MANAGEMENT of THE SMALL-SCALE FISHERIES IN ITAIPU RESERVOIR, BRAZIL

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Frugivory by the fish Brycon hilarii (Characidae) in western Brazil

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Geochemical Assessment of a Subtropical Reservoir: A Case Study in Curitiba, Southern Brazil

Suspended particles and dissolved substances in water provide reactive surfaces, influence metabolic activity and contribute to the net sediment deposition. It therefore plays an important part in the ecology and quality of the water mass. The water quality in reservoirs is crucial and it is naturally maintained by flushing and sedimentation, which continuously remove phosphorus from the water. In some reservoirs, however, these removal processes are countered by recycling of ions which could play a key role to start and/or maintain the eutrophic state. The combination of macro-, trace- and microanalysis techniques can be useful to trace pollution sources through a chemical fingerprint, whether be during an acute environmental disaster or a long-term release of pollutants. The water quality and total metal content of reservoir sediments were assessed in a reservoir, situated in the capital of the Parana State, in the South-Eastern part of Brazil. The goal of this paper was to determine the metal presence in the sediment and metal and ionic speciation in the Green River reservoir water. Water and bed sediment samples, collected from various sites during 2008 and 2009, were investigated using XRF, ICP-OES, ICP-MS, XRD and zeta potential measurements. Based on the results, the heavy metal concentration and chemical composition of the suspended matter in the water samples, as well as the sediment's chemical composition will be discussed.

Anthropogenic influences on annual flux of cations and anions at meio stream basin, São Paulo State, Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Fidelity of molluscan assemblages from the touro passo formation (pleistocene-holocene), southern brazil: taphonomy as a tool for discovering natural baselines for freshwater communities

This study is the first assessment of mollusk fossil assemblages relative to the compositional fidelity of modern mollusk living and death assemblages. It also shows that the sedimentary record can provide information on the original, non-human-impacted, freshwater malacofauna biodiversity, based on Late Pleistocene shells. The fossil mollusk assemblage from the Touro Passo Formation (Pleistocene-Holocene) was compared to living and death assemblages of the Touro Passo River, southern Brazil, revealing little resemblance between fossil and live-dead species composition. Although the living and death assemblages agree closely in richness, species composition, and species relative abundances (both proportional and rank), the fossil assemblage differs significantly from both modern assemblages in most of these measures. The fossil assemblage is dominated by the native endemic corbiculid bivalve Cyanocyclas limosa and the gastropod Heleobia aff. bertoniana. These are absent in the living assemblages, and both living and death assemblages are dominated by the alien Asiatic corbiculid C. fluminea, which is absent in the fossil assemblage. The fossil assemblage also contains, overall, a higher proportional abundance of relatively thick-shelled species, suggesting a genuine bias against the thinner- and smaller-shelled species. Our results suggest that contemporary environmental changes, such as the introduction of some alien freshwater mollusk species, together with post-burial taphonomic processes, are the main factors leading to the poor fidelity of the fossil assemblage studied. Hence, the taxonomic composition of the Late Pleistocene mollusks from the Touro Passo Formation probably would show greater similarity to present-day assemblages wherever the mollusk biodiversity is not disturbed by human activities.