Leticia Burone

Eutrophication and Bacterial Pollution Caused by Industrial and Domestic Wastes at the Baixada Santista Estuarine System – Brazil

Abstract Baixada Santistas region is world famous for its high levels of pollution, which are related to industrial, port and urban activities. Around the industrial pole of Cubatao city, high nutrient concentrations are found such as nitrate >90 μmol l −1 N –NO − 3 and phosphate >24 μmol l −1 P–PO−34. A clear gradient of dilution from the estuarys interior to its mouth is present along the natural channels, but does not reach low concentrations for all elements in the Santos Bay. Artificial urban drainage channels present accentuated differences of the nutrient concentrations inside and outside each lock. The inner channel waters, show low average values of salinity (1.33 PSU) and oxygen ( ∼2.0 ml l −1 ); pH under 8; high averages of nutrient concentrations (ammonium ∼40 μmol l −1 , nitrate ∼42, phosphate ∼2.96 μmol l −1 , silicate ∼119 μmol l −1 ); high total and faecal coliform averages (3566×103/100 and 1637×103/100 ml, respectively). Outside of the channels, on the beaches, there were high nutrient concentrations at some points and accentuated total and faecal coliform averages (91×103/100 and 28×103/100 ml, respectively). The high TC and FC contents outside of the locks show the inefficiency of the actions to prevent pollution on the beaches. These facts represent risks to local biota and human health.

Anthropogenic influences in a lagoonal environment: a multiproxy approach at the Valo Grande mouth, Cananéia-Iguape system (SE Brazil)

The Cananeia-Iguape system, SE Brazil, consists of a complex of lagoonal channels, located in a United Nations Educational, Scientific and Cultural Organization (UNESCO) Biosphere Reserve. Nevertheless, important environmental changes have occurred in approximately the last 150 yrs due to the opening of an artificial channel, the Valo Grande, connecting the Ribeira de Iguape River to the lagoonal system. Our objective is to assess the historical record of the uppermost layers of the sedimentary column of the lagoonal system in order to determine the history of environmental changes caused by the opening of the artificial channel. In this sense, an integrated geochemical-faunal approach is used. The environmental changes led significant modifications in salinity, in changes of the depositional patterns of sediments and foraminiferal assemblages (including periods of defaunation), and, more drastically, in the input of heavy metals to the coastal environment. The concentrations Pb in the core analyzed here were up to two times higher than the values measured in contaminated sediments from the Santos estuary, the most industrialized coastal zone in Brazil.

Spatial distribution of organic matter in the surface sediments of Ubatuba Bay (Southeastern - Brazil)

Analyses of organic matter content, organic carbon, nitrogen, sulfur and granulometric variables were performed on 101 surface sediment samples from Ubatuba Bay in order to investigate the spatial distribution of organic matter, its origin and the relationships among its components. The samples were obtained with a manual corer, from water depths between 1 and 15m during 5 cruises of the R/V ‘‘Veliger II’’, two months apart. Pearson correlation, regression and Principal Component Analysis (PCA) statistical methods were used to analyze the data. Strong correlations between organic matter and fine sediment fractions were obtained. The PCA revealed at least two main sample groups that reflect the different environmental conditions prevalent in the bay. There is a simple linear relationship between organic carbon content and the organic matter content determined by the calcination technique. Taking into account that the analysis of organic matter content is less expensive and less time consuming than the analysis of organic carbon, the present method of estimation can be useful when fast evaluation of the organic carbon content is needed for samples from similar environments.

The Southern Brazilian shelf: general characteristics, quaternary evolution and sediment distribution

S to 22 S the Southern Brazilian shelf constitutes the only part of the Brazilian shelf with a subtropical to temperate environment. The studies on the different geological aspects of the area began in the 1960´s and have recently been reassessed after studies related to the determination of the Economic Exclusive Zone. In terms of morphology, the Southern Brazilian shelf may be divided into three sectors, the Sao Paulo Bight, the Florianopolis-Mostardas Sector and the Rio Grande Cone, characterized by conspicuous differences in terms of geological determining factors, bathymetry, declivities and the presence of canyons and channels. Despite the existence of hundreds of radiocarbon datings the sea level changes curve of southern Brazil during the Last Glacial Cycle is still a matter of debate. A recent controversy on the Middle and late Holocene sea level changes curve raised the question of the amplitude of the oscillations which occurred in the period. Also, a few but relatively consistent radiocarbon datings suggest the occurrence of a high sea level during Isotope Stage 3. In terms of sedimentary cover the Southern Brazilian shelf exhibits a very strong hydrodynamic control, both latitudinal and bathymetrical. The sector southward from 25

Radiocarbon geochronology of the sediments of the São Paulo Bight (southern Brazilian upper margin)

The aim of this work was to generate an inventory of the data on radiocarbon datings obtained from sediments of the São Paulo Bight (southern Brazilian upper margin) and to analyze the data in terms of Late Quaternary sedimentary processes and sedimentation rates. A total of 238 radiocarbon datings from materials collected using differents ampling procedures was considered for this work. The sedimentation rates varied from less than 2 to 68 cm.kyr(-1). The highest sedimentation rate values were found in a low-energy (ría type) coastal system as well as in the upwelling zones of Santa Catarina and Cabo Frio. The lowest rates were found on the outer shelf and upper slopes. Our results confirm the strong dependency of the shelf currents, with an emphasis to the terrigenous input from the Río de La Plata outflow which is transported via the Brazilian Coastal Current, as well as of the coupled Brazil Current - Intermediate Western Boundary Current (BC-IWBC) dynamics on the sedimentary processes. At least three indicators of the paleo sea level were found at 12200 yr BP (conventional radiocarbon age) (103 meters below sea level - mbsl), 8300-8800 cal yr BP (13 mbsl) and 7700-8100 cal yr BP (6 mbsl).

Diatoms, protein and carbohydrate sediment content as proxies for coastal eutrophication in Montevideo, Rio de la Plata Estuary, Uruguay

A study on sediment surface diatom composition in relation to both protein/carbohydrate content and salinity was carried out in Montevideo Bay and the adjacent coastal zone. Samples were seasonally taken during one year along a human impact gradient, and the trophic conditions were assessed from the biochemical composition of the surface sediment organic matter. The co-occurrence of the marine-brackish (Actinocyclus curvatulus, Actinocyclus gallicus, Coscinodiscus excentricus, Coscinodiscus radiatus, Hyalodiscus subtilis, Paralia sulcata) and freshwater diatom flora (Aulacoseira granulata, Aulacoseira italica, Aulacoseira muzzanensis, Actinocyclus normanii, Amphora copulata, Cyclotella meneghiniana, Nitzschia linearis), suggests myxohaline estuarine conditions in the study area. The sampling stations located within the bay, close to several contamination sources, exhibited hypertrophic conditions as indicated by the highest levels of protein content, but also by the high relative abundances of Actinocyclus normanii and Cyclotella meneghiniana, as both diatom species are very well established cosmopolitan proxies of aquatic degradation. The levels of both protein and carbohydrate content, but also photosynthetic pigments, recorded in the adjacent coastal zone suggest meso-eutrophic conditions as contamination levels from the inner bay might become diluted off shore. Multivariate diatom species-environmental data relationships, indicate that the trophic gradient is hierarchically more important than salinity in explaining the diatom distribution. The present data imply an improvement in our ability of assessing organic contamination in the study area, since both biological and biopolymer variables were introduced for the first time as a tool for assessing the benthic health/degradation in one of the most populated regions of the Rio de la Plata.

Inorganic and organic geochemical fingerprinting of sediment sources and ocean circulation on a complex continental margin (São Paulo Bight, Brazil)

In this study, we use inorganic (metal) and organic (bulk and molecular) markers in sediment samples of the south-eastern Brazilian margin to investigate the response of geochemical fingerprints to the complex hydrodynamic processes present in the area. Results indicate the potential of export of terrigenous siliciclastic and organic constituents to the upper slope, even in an area with limited fluvial supply. Metal contents and especially the ln(Ti /Al) and ln(Fe /K) ratios make it possible to recognise the extension of shelf sediments toward the upper slope. Potassium, here expressed as ln(K /Sc) and ln(K /Al) ratios used as proxies of illite– kaolinite variations, proved to be an important parameter, especially because it allowed us to decipher the imprint of the northward flow of the Intermediate Western Boundary Current (IWBC) in comparison to the southward flows of the Brazil Current (BC) and Deep Western Boundary Current (DWBC). Using organic matter analyses, we were able to evaluate the extent of terrestrial contributions to the outer shelf and slope, even without the presence of significant fluvial input. In addition, molecular markers signify a slight increase in the input of C4-derived plants to the slope sediments, transported from distant areas by the main alongshore boundary currents, indicating that the terrestrial fraction of the organic matter deposited on the slope has a distinct origin when compared to shelf sediments.

A chemical analysis of sediment pore water in oxygen-free atmosphere: application to a contaminated area

. 1990; van Raaphorst & Malschaert, 1996). However, sediment pore water sampling is tedious and requires the use of special equipment due to the possible effects and potential chemical alterations resulting from incorrect procedures. It is known that, with the exception of the uppermost sediment layers (of 1 to 3 cm thickness), most fine-grained deposits are anoxic but oxidize rapidly upon exposure to air. The oxidation of the sediments brings about rapid changes in the kinds of redox-sensitive chemicals dissolved in the sediment pore water. During pore water collection and sample processing the maintenance of an oxygen-free atmosphere is essential for the measurement of some of the original chemical constituents (Manheim, 1976; Kriukov & Manheim, 1982). Results from many studies indicate that nutrient concentrations of pore water may be much higher than those of the water column (Ohle, 1977; Esteves, 1988; van Raaphorst & Malschaert, 1996). Generally, glove bags or glove boxes should be used to handle the pore water samples that best represent the natural sedimentary environment. It is essential, to ensure these conditions, that any exposure of the sediment and sampled water to the atmosphere must be completely avoided by guaranteeing oxygen-free conditions during the entire process of sediment sample manipulation (Adams, 1991). This can be achieved by working in the inert atmosphere of such a gas as nitrogen, argon or, in some cases, helium or carbon dioxide. __________

Foraminíferos bentônicos no talude continental, Platô de São Paulo e cânions da Bacia de Campos

Neste capitulo e apresentado um estudo ecologico de foraminiferos bentonicos vivos, coletados em estacoes localizadas no talude continental, Plato de Sao Paulo e cânions da Bacia de Campos, no ano de 2008 (periodo seco) e de 2009 (periodo chuvoso). As estacoes seguem nove transectos de 400 a 3.000xa0m de profundidade. O estudo teve como objetivo investigar mudancas na densidade, diversidade e composicao de foraminiferos bentonicos, ao longo desses transectos, em resposta a fatores ambientais. As mudancas na comunidade seguem o gradiente batimetrico e sao controladas pela disponibilidade e, provavelmente, qualidade do alimento. Os maiores valores medios de densidade, diversidade e riqueza, assim como o predominio de foraminiferos calcarios hialinos e especies infaunais refletem maior aporte de alimento recebido de forma continuada, nas estacoes mais rasas (400xa0m). Nas estacoes entre 700 e 1.000xa0m de profundidade, a densidade de individuos diminui e a presenca de especies oportunistas, que se reproduzem rapidamente na sequencia de pulsos de fitodetritos, e o reflexo de um aporte alimentar possivelmente sazonal. O aumento consideravel dos foraminiferos textulariideos, o decrescimo continuo na densidade de individuos e tambem nos valores do Indice de Produtividade de Foraminiferos Bentonicos (BFHP), a medida que aumenta a profundidade e valores extremamente baixos nas estacoes mais profundas (3.000xa0m), indicam condicoes tipicamente oligotroficas nesse setor da Bacia de Campos. A comparacao de dados de densidade e de composicao de especies nos periodos seco e chuvoso permite-nos inferir que no periodo chuvoso o aporte de alimento foi maior. Os valores de densidade e biomassa de foraminiferos bentonicos vivos permitem-nos deduzir que o Cânion Almirante Câmara constitui um local de maior aprisionamento de materia orgânica entre as isobatas de 400 a 1.000xa0m, em comparacao ao talude aberto para os mesmos limites de profundidades. A natureza do substrato e provavelmente os teores de oxigenio nas aguas do fundo oceânico revelaram-se fatores condicionantes secundarios na distribuicao desses organismos.