Elisabete de Santis Braga

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.

Observation of regeneration of nitrate, phosphate and silicate during upwelling off Ubatuba, Brazil, 23°S

Off the Brazilian coast near Ubatuba, an upwelling event of South Atlantic Central Water (SACW) has been observed that transfer nutrient-rich water from 300 to 400 m depth onto the continental shelf to depths less than 35 m. Earlier work showed that SACW is present on the shelf quite frequently; however, nutrient data as natural tracers of water masses, are largely undocumented so far. During the upwelling process the water advanced over the shelf increasing its nutrients concentrations and depleting its content of dissolved oxygen due to the regeneration process. The ratios of regeneration relative to their open ocean origin amount to 4.6 mu M for nitrate, 0.43 mu M for phosphate and 5.7 mu M for silicate on average, while the dissolved oxygen depletes by 114.9 mu M,

Use of Cathorops spixii as bioindicator of pollution of trace metals in the Santos Bay, Brazil

In the present study Cathorops spixii, was evaluated as a bioindicator fish for trace metal pollution. Concentrations of cobalt (Co), iron (Fe), selenium (Se) and zinc (Zn) were determined by Instrumental Neutron Activation Analysis in liver. Mercury (Hg) and methyl-mercury (MeHg) were analyzed by Cold Vapor Atomic Absorption Spectrometry in muscles and livers. High concentrations of Co, Fe, Se and Zn were observed in C. spixii from Santos Bay in comparison to fish collected in a non-polluted site in the same Brazilian coast. These trace metal concentrations were out of the permissible levels for human consumption. Although, Hg and MeHg levels were low, the C. spixii could still be used as an effective bioindicator to observe trace metal behaviors in the environment in function of the bioaccumulation process observed mainly by other analyzed trace metals. Thus, the use of this species is strongly recommended to monitor the effects and behavior of trace metal pollution in aquatic ecosystems in Brazil due to its bioaccumulation function.

Biomarkers of exposure to metal contamination and lipid peroxidation in the benthic fish Cathorops spixii from two estuaries in South America, Brazil

Biomarkers as lipid peroxidation, metallothionein and δ-aminolevulinic acid dehydratase were determined in Cathorops spixii to compare the biological responses of this fish from estuaries with distinct anthropogenic influence. Three areas were selected in two estuaries in accordance with the levels of contamination for the polluted (Santos/São Vicente) and with the hydrodynamic characteristics for the non-polluted (Cananéia) estuary. Water characteristics and mercury levels in C. spixii confirmed a high human influence in the polluted system. In general, the biomarkers showed differences between the estuaries, suggesting disturbances in the specific cell mechanisms due to the presence of multiple xenobiotics in the contaminated system. Therefore, these biomarkers are recommended to promote more accurate information about the exposure to pollutants. Additionally, the study of the effect of the multiple xenobiotics on resident species such as the benthic fish C. spixii can favor a better assessment of the environmental quality of these systems.

Total mercury in sediments and in Brazilian Ariidae catfish from two estuaries under different anthropogenic influence

Santos-São Vicente estuary, located in São Paulo State, Brazil, has a history of contamination by inorganic chemicals such as mercury (Hg). In the 1980s the Cubatão was considered one of the most polluted sites in the world as a consequence of the intense industrial activities located in the city close to the estuary. To provide data and evaluate the local biota, total mercury (THg) contents were determined in sediments and in fish, Cathorops spixii, from different areas of the Santos-São Vicente estuary. For comparison, samples were also collected in a non-polluted system with similar hydrochemistry characteristics, the Cananeia estuary. The water characteristics and THg levels in sediment and fish samples confirmed a high human influence in the Santos-São Vicente estuary. The lowest THg values, observed in Cananeia, were evidence of low anthropogenic influence. High values observed in Santos-São Vicente show the necessity for a monitoring program.

Mercúrio total em cabelo de crianças de uma população costeira, Cananéia, São Paulo, Brasil

Os niveis de mercurio (Hg) total em cabelos estao diretamente relacionados a alimentacao, particularmente ao consumo de peixes por populacoes costeiras com grande representacao caicara. No presente estudo foram avaliados os niveis de mercurio total em cabelos de criancas com idade entre 4 e 12 anos, pertencente a tres escolas publicas da cidade de Cananeia, Sao Paulo, Brasil. Os resultados obtidos (mediana e intervalo) para mercurio total foram de: 0,04mg.kg-1 (0,01-0,77mg.kg-1), 0,39mg.kg-1 (< 0,01-3,33mg.kg-1) e 0,39mg.kg-1 (< 0,01-2,81mg.kg-1) considerando as escolas ES1, ES2 e ES3, respectivamente. Em geral, os valores encontrados estiveram bem abaixo do valor preconizado pela Organizacao Mundial da Saude para uma populacao adulta nao exposta ao mercurio (2,0mg.kg-1). Os baixos valores observados e a inexistencia de valores de referencia para mercurio total em cabelos de criancas brasileiras possibilitam a consideracao desses valores como possivel referencia nacional em cabelos de populacoes costeiras, uma vez que foram obtidos em regiao de baixo impacto ambiental.

Biochemical changes in the liver and gill of Cathorops spixii collected seasonally in two Brazilian estuaries under varying influences of anthropogenic activities

In order to understand environmental health by the use of a bioindicator species in estuaries, biochemical responses observed in the catfish Cathorops spixii such as catalase (CAT), glutathione-S-transferase (GST), lipid peroxidation (LPO) and acetylcholinesterase (AChE) were evaluated in liver and muscle. Furthermore, histological changes were also verified in liver and gills preparations. Fish were collected in three sites of the Santos-São Vicente estuary located at São Paulo (Brazil), subjected to varying levels of inputs of pollutants. For a reference site, specimens were sampled at Cananéia estuary at southern coast of São Paulo, a region with low anthropogenic influence. In general, no significant seasonal differences in antioxidant enzymes and lipid peroxidation responses were found in the organisms from the Cananéia estuary. However, in the polluted estuary (Santos-São Vicente), biochemical responses were observed by increases in GST hydroperoxides and decreases in AChE activities in the summer. Inhibition of AChE expression in fish from different areas of the Santos-São Vicente estuary in the summer was also found and can indicate neurotoxic effects in these organisms. Histopathological observation of gill and liver showed severe lesions, such as lamellar fusion and necrosis.

Recent benthic foraminiferal distribution and related environmental factors in Ezcurra Inlet, King George Island, Antarctica

Abstract This investigation attempts to determine which environmental parameters of the bottom water and sediment control recent foraminifera fauna at Ezcurra Inlet (King George Island, Antarctica), using data collected during four summers (2002/03, 2003/04, 2004/05 and 2006/07). The study revealed that Ezcurra Inlet contain typical Antarctic foraminifera fauna with three distinct assemblages and few differences in environmental parameters. The species Bolivina pseudopunctata, Fursenkoina fusiformis, Portatrochammina antarctica, and Adercotryma glomerata were abundant in the samples. An elevated abundance, richness and diversity were common at the entrance of the inlet at depths greater than 55 m, where the inlet was characterized by low temperatures and muddy sand. In the inner part of the inlet (depth 30–55 m), richness and diversity were low and the most significant species were Cassidulinoides parkerianus, C. porrectus, and Psammosphaera fusca. Shallow waters showed low values of richness and abundance and high temperatures coupled with coarser sediment. In areas with high suspended matter concentrations and pH values associated with low salinity the most representative species were Hippocrepinella hirudinea and Hemisphaerammina bradyi.

Coastal water exchange rate studies at the southeastern Brazilian margin using Ra isotopes as tracers

Abstract The Sao Paulo Bight is the arc-shaped part of the southeastern Brazilian margin extending from 23°S to 28°S. To assess the cross-shelf Ra distributions in Sao Paulo Bight, four shore-perpendicular profiles were collected up to 100 km offshore from 23 to 26 February 2003 (summer). All samples studied here were taken in the selected area between latitudes 23°15′S and 25°50′S and longitudes 44°W and 46°W, in order to estimate coastal mixing rates and groundwater discharge fluxes. The activity concentrations of 223 Ra in surface seawater varied from 0.002 to 0.4 mBq L −1 , 224 Ra in excess from 0.02 to 2.5 mBq L −1 , 226 Ra from 1.2 to 1.8 mBq L −1 and 228 Ra from 0.4 to 4.4 mBq L −1 . The 223 Ra/ 224 Ra and 228 Ra/ 226 Ra activity ratios observed in seawater samples ranged from 0.03 to 2.6 and from 0.3 to 2.4, respectively. These results seem to indicate that Ra isotopes from 232 Th series prevail in a major number of samples, when compared with Ra isotopes from 238 U and 235 U series. Considering the results obtained in the summer 2003, shore-perpendicular profiles of 223 Ra and 224 Ra in surface waters along the coast were modeled to yield eddy diffusion coefficients.

Algal growth potential as an indicator of eutrophication degree in coastal areas under sewage disposal influence

Algal growth potential was used to quantify the degree of eutrophication of three coastal regions in São Paulo, Brazil which are subject to sewage disposal. Surface water was collected in Praia Grande, Santos, Guarujá and São Sebastião during two surveys (low tourist season—October 1997 and high tourist season—March 1998). Water was filtered and used in chlorophyll-a and nutrient analyses and in bioassays. Samples were inoculated with the diatom Phaeodactylum tricornutum Bohlin, and then subdivided into seven replicates. During a ten days experiment, in vivo fluorescence was performed and algal growth potential was calculated. Values were expressed as absolute in vivo fluorescence, as well as with a ratio of in vivo fluorescence of sample in relation to the fluorescence of control sea water for each treatment which defines the trophic status. The results of these bioassays showed a growing degree of eutrophication among regions: Praia Grande ∼ São Sebastião → Guarujá → Santos. It also identified sewage disposals and estuarine discharges as the main sources causing eutrophication. This bioassay technique is an important tool for environmental pre-monitoring studies, giving useful results in a short time.