Distribution of acid-volatile sulfides and simultaneously extracted metals in Guanabara Bay: combination of anthropogenic, sedimentological, and geochemical processes.

Coastal sedimentary systems are affected by continental and marine metal pollutant inputs associated with different hydrodynamic characteristics and geochemical processes. These include the formation of acid-volatile sulfides (AVS) within sediments, which affects metal bioavailability and associated aquatic biota toxicity risks. Physicochemical changes in these environments in the face of extreme natural or man-made environmental influences can dramatically alter metal bioavailability and toxicity through metal binding and immobilization as insoluble sulfides. Surface sediments from Guanabara Bay, river mouths, and two mangrove areas were collected, and AVS and simultaneously extracted metals Cd, Cu, Fe, Mn, Ni, Pb, and Zn and ΣSEM were determined to assess sediment quality. A severe eutrophication history favored AVS concentrations exceeding or close to the sum-SEM concentrations, demonstrating that AVS play an important role in making trace metals unavailable for assimilation by living organisms, mitigating the risks of contamination for the local biota. This eutrophication-driven sulfide accumulation may attenuate the sediment toxicity in sites heavily polluted by metals, while some fewer eutrophic sites became more exposed to metals in excess to AVS.

Beach sand plastispheres are hotspots for antibiotic resistance genes and potentially pathogenic bacteria even in beaches with good water quality.

Massive amounts of microplastics are transported daily from the oceans and rivers onto beaches. The ocean plastisphere is a hotspot and a vector for antibiotic resistance genes (ARGs) and potentially pathogenic bacteria. However, very little is known about the plastisphere in beach sand. Thus, to describe whether the microplastics from beach sand represent a risk to human health, we evaluated the bacteriome and abundance of ARGs on microplastic and sand sampled at the drift line and supralittoral zones of four beaches of poor and good water quality. The bacteriome was evaluated by sequencing of 16S rRNA gene, and the ARGs and bacterial abundances were evaluated by high-throughput real-time PCR. The results revealed that the microplastic harbored a bacterial community that is more abundant and distinct from that of beach sand, as well as a greater abundance of potential human and marine pathogens, especially the microplastics deposited closer to seawater. Microplastics also harbored a greater number and abundance of ARGs. All antibiotic classes evaluated were found in the microplastic samples, but not in the beach sand ones. Additionally, 16 ARGs were found on the microplastic alone, including genes related to multidrug resistance (blaKPC, blaCTX-M, tetM, mdtE and acrB_1), genes that have the potential to rapidly and horizontally spread (blaKPC, blaCTX-M, and tetM), and the gene that confers resistance to antibiotics that are typically regarded as the ultimate line of defense against severe multi-resistant bacterial infections (blaKPC). Lastly, microplastic harbored a similar bacterial community and ARGs regardless of beach water quality. Our findings suggest that the accumulation of microplastics in beach sand worldwide may constitute a potential threat to human health, even in beaches where the water quality is deemed satisfactory. This phenomenon may facilitate the emergence and dissemination of bacteria that are resistant to multiple drugs.

Oil spill environmental sensitivity mapping of Rio de Janeiro, Brazil.

The current case study focuses on the Environmental Sensitivity Index (ESI) mapping of Guanabara Bay, Rio de Janeiro, Brazil - a region at risk from petroleum sector pollution. By mapping 981.5 km of coastline and classifying it in 10 oil sensitivity indices, we integrated biotic resources, socioeconomic attributes, and geoenvironmental diversity into a georeferenced database. Results reveal a high oil sensitivity of the bay, with approximately 89 % of the mapped coast scoring ESI 8 and ESI 10. These scores comprise, respectively, estuarine and solid substrate habitats that are sheltered from wave action. Notably, numerous manufacturing and oil handling plants, along with intensive urbanization, also contribute to the bay's oil sensitivity. Additionally, the rich biotic diversity in the study area, particularly in protected areas housing 79 conservation units, further amplifies its environmental vulnerability. This study aims to serve as a reference for detailed ESI mapping of coastal areas in tropical rainy zones with significant environmental diversity, industrial development, and a dense population.

Assessment of eutrophication from phosphorus remobilization after resuspension of coastal sediments from an urban tropical estuary.

Dredging activities cause sediment resuspension, which can change the bioavailability of nutrients such as phosphorus (P) in aquatic ecosystems due to remobilization. This study evaluated the remobilization of P in the solid and dissolved phase before and after sediment resuspension in the Meriti and Iguaçu River estuaries and the Rio de Janeiro and Niterói harbor in Guanabara Bay (Rio de Janeiro, Brazil). Three water and sediment samples were collected at each point. Dissolved phosphorus (DP), total phosphorus (TP), organic phosphorus (OP), and inorganic phosphorus (IP) were analyzed before and after resuspension. Resuspension directly impacted the fine-grained samples, causing the release of P into the water column after resuspension, increasing eutrophication of the estuary and risk to biota. The phosphorus enrichment index (PEI) was calculated in the four areas, and in all areas, the index was above 1, which means high ecological risk. The area with sandy granulometry and a lower percentage of organic matter showed an increase in the index after resuspension. The resuspension may impact the increase of eutrophication in some areas, due to the remobilization of the sediment and the adsorbed contaminants.

Spatial distribution of total mercury and methylmercury in the sediment of a tropical coastal environment subjected to heavy urban inputs.

Jurujuba Cove is located in Guanabara Bay (adjacent to highly populated city of Rio de Janeiro, Brazil), which receives diffuse sources of contaminants along with two main freshwater inputs (the Cachoeira and Icaraí rivers), and hosts mussel farms. The main goal of this work was to evaluate the total mercury (THg) and methylmercury (MeHg) concentrations distributions in the sediments of the cove and their associations with physical and chemical parameters, thereby assessing their geochemical behavior. Twenty samples of surface sediments were collected and characterized for grain size, pH, redox potential, organic carbon, total phosphorus, THg and MeHg. Spatial distribution maps were produced for each parameter and a principal components analysis was carried out, to assess THg and MeHg behavior and their relationships with other parameters. The principal components analysis showed that grain size functions as the main diluting agent. The highest THg concentrations were observed in the mussel-farm area (656.1 ng g-1), and were related to fine grain size and elevated organic carbon values. High MeHg concentrations also occurred in the center of the cove, probably favored by high organic carbon content (low-energy environment). Total phosphorus concentrations indicate that Cachoeira River is a possible source of sewage, but little mercury seems to come from it. The results showed that although total mercury concentrations are elevated, with exception of a few locations, small methylmercury convertion rates were recorded in the sediments.

Fast screening of enteropathogens in marine water samples.

This study aimed to fast screen the microbiological contamination of recreational waters using a TaqMan Array Card (TAC), a multiplexed platform designed for the simultaneous detection of 35 enteropathogens. Surface and deep marine water samples were concentrated by skimmed milk flocculation and processed for nucleic acid extraction protocol using QIAamp Fast DNA Stool Mini Kit. Twelve microorganisms and parasites, including bacteria (n = 6), protozoa (4), and viruses (2), were detected in 85.7% (24/28) of samples. Campylobacter (82.1%), Cryptosporidium (39.3%), and adenovirus (14.3%) were the most detected pathogens. Neither fungi nor helminths were detected. A spatial pollution profile of microbiological contamination was observed in the area. Methodologies for simultaneous detection of multiple pathogens, such as TAC, can assist decision-makers by providing a quick assessment of the microbiological water quality in areas used for recreational purposes, which in many cases are in accordance with the bacteriological indicators.

Multiproxy analysis in contaminated sediments from Niterói Harbour (Guanabara Bay), Brazil.

Harbours are located in major urban centres around the world and are of great economic importance to the cities in their surroundings. However, the intense traffic of boats and ships can generate environmental impacts that can directly affect the local biota as well as the population that lives in surrounding areas. Therefore, this work aimed to analyse the surface sediment of the Niterói Harbour using chemical, biological and micropalaeontological tools to investigate the environmental condition of this important harbour in Rio de Janeiro State. The pseudototal trace metal data analysed in the surface samples showed values far above those of the greater Guanabara Bay background. These data were corroborated by a high mortality rate of Artemia sp. and elevated presence of the bacterium Vibrio fischeri, indicating a high rate of local pollution. Dinoflagellate cysts also showed a direct response to high values of pseudototal trace metals. The data obtained in this study emphasize a need for greater monitoring of ports since the experience gained through this study in a Brazilian harbour can serve as an example for the management of other harbours located in large urban centres around the world.

Potencial poluidor da disposição final de resíduos sólidos nas águas da bacia hidrográfica da Baía de Guanabara - RJ / Polluting potential of solid waste final disposal in the waters of the hydrographic region of the Guanabara Bay basin - RJ

RESUMO A região hidrográfica da Bacia da Baía de Guanabara integra 17 municípios do estado do Rio de Janeiro, entre os quais estão os maiores geradores de resíduos sólidos: São Gonçalo, Belford Roxo, Nova Iguaçu, Rio de Janeiro e Duque de Caxias. O lixiviado, efluente altamente tóxico, quando descartado de maneira inadequada, pode provocar diversos impactos negativos nos corpos hídricos. Este trabalho apresenta, por meio de uma abordagem qualitativa e quantitativa, as áreas de destinação final de resíduos sólidos e os principais corpos hídricos vulneráveis e potencialmente receptores de lixiviado da região hidrográfica da Bacia da Baía de Guanabara. ­Realizou-se uma pesquisa em documentação legal das centrais de tratamento de resíduos, aterros controlados e vazadouros, relatórios das visitas técnicas do Grupo de trabalho Chorume, informações do ICMS Ecológico 2019-2020 — ano de referência 2018 — e demais documentos institucionais pertinentes ao objeto da pesquisa. Observou-se que, impulsionados pela Política Nacional de Resíduos Sólidos, pelo Imposto sobre Circulação de Mercadorias e Serviços Ecológico e por programas do Governo do Estado, como o Pacto pelo Saneamento (Rio + Limpo e Lixão Zero), os municípios da região hidrográfica da Bacia da Baía de Guanabara, em sua maioria, encerraram seus lixões nos últimos 10 anos. Não obstante, grande parte dos aterros sanitários construídos não dispõe de estações de tratamento de lixiviado que atendam à vazão gerada e os aterros controlados e lixões, ativos e desativados, seguem produzindo lixiviado e descartando nos corpos hídricos da Baía de Guanabara.

ABSTRACT The hydrographic region of the Guanabara Bay basin includes 17 municipalities in the state of Rio de Janeiro and among them are the largest solid waste generators in the state: São Gonçalo, Belford Roxo, Nova Iguaçu, Rio de Janeiro, and Duque de Caxias. Leachate, a highly toxic effluent, can cause several negative impacts on water bodies when improperly disposed of. This study, through a qualitative and quantitative approach, maps the areas used for the final disposal of solid waste within the hydrographic region of the Guanabara Bay basin and vulnerable water bodies which are potential receivers of leachate. Research was carried out analyzing legal documentation for sanitary and controlled landfills and dumps, reports of technical visits of the Leachate Work Group, data from the 2018 Ecological Imposto sobre Circulação de Mercadorias e Serviços (reduced state tax incentives) and other institutional documents related to the research object. It was observed that most of the municipalities in the hydrographic region of the Guanabara Bay basin closed their landfills within the last 10 years, driven by the National Solid Waste Policy, Ecological Imposto sobre Circulação de Mercadorias e Serviços and state government programs, such as the Pact for Sanitation (Rio + Clean and Zero Dump). Nevertheless, most of these closed sites do not have leachate treatment stations that meet the flow rate and thus continue producing leachate and discarding it into the water bodies of Guanabara Bay.

Ecological risks associated to trace metals of contaminated sediments from a densely urbanized tropical eutrophic estuary.

The sediment contamination by trace metals in coastal aquatic ecosystems is a worldwide environmental problem, since metals can be toxic, persistent, and bioaccumulated. In case of natural events, such as storms, or anthropogenic activities, like dredging, the sediment resuspension to the water column occurs and can solubilize metals, probably increasing their bioavailability and consequently the risk to aquatic life. This study evaluated the bioavailability on reactive trace metals (Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) in estuarine sediments from Iguaçu and Meriti Rivers, both in the drainage basin of Guanabara Bay (Rio de Janeiro, Brazil). Additionally, a discussion about the anthropogenic interference throughout time of six short sediments cores, calculating three different indexes (contamination factors, CF; potential ecological risk index for a single heavy metal, Eif for short; potential ecological risk, PERI) was performed. It was considered as reactive phase, the metal concentrations obtained using a weak acid extraction (in HCl 1 mol L-1 solution). Zn presented high concentrations after resuspension, being above effect range medium (ERM) (52.81 to 1337.4 mg kg-1). The CF indicated very high contamination degree for Cu (14.62 to 17.96) and Zn (27.80 to 35.85) for both rivers. The Eif for short presented higher risk to Cu and Zn for Iguaçu and Meriti rivers. PERI index classified Meriti River samples as severely contaminated (238.10 to 351.62).

Diving into the unknown: identification of antimicrobial resistance hotspots in a tropical urban estuary.

Antimicrobial resistance is widely studied and well-characterized from a clinical perspective. However, considerably less information is available regarding resistance in environmental settings, especially in aquatic habitats. This study presents data regarding the occurrence, distribution and the antimicrobial susceptibility profile of bacteria isolated from Guanabara Bay (GB), a heavily polluted tropical urban estuary and an important tourist attraction in Rio de Janeiro, Brazil. Water samples from sites characterized by growing degrees of pollution were analysed by culture-dependent methods, revealing the presence of multidrug-resistant bacteria and clinically relevant indicators of antimicrobial resistance, such as extended-spectrum beta-lactamases. Isolates were identified by mass spectrometry, which indicated the presence of potential human pathogens such as Aeromonas spp. and Vibrio spp. Bacteria harbouring beta-lactam resistance genes were also detected. Although GB is widely used as a recreational and fishing area, there is a substantial knowledge gap regarding the monitoring of antimicrobial resistance and the risk that exposure to these waters poses to public health. Thus, this study reveals new information that calls for better comprehension of antimicrobial resistance in aquatic environments, especially those used for recreational purposes.

Vibrio Species in an Urban Tropical Estuary: Antimicrobial Susceptibility, Interaction with Environmental Parameters, and Possible Public Health Outcomes.

The genus Vibrio comprises pathogens ubiquitous to marine environments. This study evaluated the cultivable Vibrio community in the Guanabara Bay (GB), a recreational, yet heavily polluted estuary in Rio de Janeiro, Brazil. Over one year, 66 water samples from three locations along a pollution gradient were investigated. Isolates were identified by MALDI-TOF mass spectrometry, revealing 20 Vibrio species, including several potential pathogens. Antimicrobial susceptibility testing confirmed resistance to aminoglycosides, beta-lactams (including carbapenems and third-generation cephalosporins), fluoroquinolones, sulfonamides, and tetracyclines. Four strains were producers of extended-spectrum beta-lactamases (ESBL), all of which carried beta-lactam and heavy metal resistance genes. The toxR gene was detected in all V. parahaemolyticus strains, although none carried the tdh or trh genes. Higher bacterial isolation rates occurred in months marked by higher water temperatures, lower salinities, and lower phosphorus and nitrogen concentrations. The presence of non-susceptible Vibrio spp. was related to indicators of eutrophication and sewage inflow. DNA fingerprinting analyses revealed that V. harveyi and V. parahaemolyticus strains non-susceptible to antimicrobials might persist in these waters throughout the year. Our findings indicate the presence of antimicrobial-resistant and potentially pathogenic Vibrio spp. in a recreational environment, raising concerns about the possible risks of human exposure to these waters.

Environmental and anthropic variabilities at Guanabara Bay (Brazil): A comparative perspective of metal depositions in different time scales during the last 5,500 yrs.

The determination of age-dated metal sediment accumulation rates in a representative South American bay is able to portray the dimension of human impacts during the colonial occupation and industrial periods. Many studies have assessed metal distribution and chronology at Guanabara Bay, in Brazil. However, understanding natural variabilities associated to paleoclimatic changes and comparing these natural variabilities to anthropogenic processes are not well established to date. Accurate geochronological control integrating ages determined by 210Pb and 14C chronologies through an exponential spline fit model allowed for a precise definition of changes associated to the holocene marine transgression, as well as the colonial period, leading to intense land use changes, and the industrial period. The reference values of the system were defined based on their concentrations and the accumulation rates of ecotoxicologically important metals. Al, Ba, Fe, Cd, Cu, Cr, Li, Ni, Mn, Pb, Si, Ti, V, and Zn distributions were determined in a Guanabara Bay core (BG-28) by the EPA 3051 method. Elemental distribution profile assessment allowed for the identification of variabilities associated to weathering processes, predominantly of lithogenic origin, mainly for Al, Ba, Fe, Li, Si, and V. Weathering processes occurred simultaneously to land use changes in the drainage basin since the colonial period, at 400 cal yr BP, and during the industrial period, mainly after the 1960s, denoted by Cd, Cr, Cu, Mn, Pb and Zn increases. The highest average metal enrichment values metals associated to industrial processes reached 5.95, with 119.1-fold higher accumulation rates than the background accumulation values observed between 4200 and 500 cal yr BP.

A new catfish species of Microcambeva Costa Bockmann 1994 (Siluriformes: Trichomycteridae) from a coastal basin in Rio de Janeiro State, southeastern Brazil.

Microcambeva bendego, a small psammophilous catfish species, is described from the rio Guapi-Macacu basin at Guanabara Bay in Rio de Janeiro State, an Atlantic Forest remnant. This coastal drainage has been explored by several naturalists and fish researchers since the 19th century. It is a drainage with remarkably high endemism and species richness, and some recently-described and threatened species. The new species is distinguished from all congeners by two distinctive characters: long finger-like projections in the branchial isthmus and a large opercular patch of odontodes with 19 odontodes. Due to the paucity of specimens (n=3) osteological features of the new species were accessed by CT-Scan images of the holotype. Microcambeva bendego shares putative synapomorphies with two congeners, M. ribeirae and M. filamentosa, such as the fusion of supraorbital pore s6, the absence of ossification in the anterior autopalatine cartilage, the presence of an elongated and wide posterior process of the autopalatine, and a concavity on the dorsal process of the opercle. Those characters suggest that M. bendego is more closely related to those two species from the rio Ribeira de Iguape basin than to other congeners. The biogeography and conservation status of M. bendego are also discussed.

Skin and stinger bacterial communities in two critically endangered rays from the South Atlantic in natural and aquarium settings.

Bacterial communities of two critically endangered rays from the South Atlantic, the butterfly ray (Gymnura altavela) and the groovebelly ray (Dasyatis hypostigma), were described using 16S rRNA gene metabarcoding. The study characterized the bacterial communities associated with (i) G. altavela in natural (in situ) and aquarium (ex situ) settings, (ii) skin and stinger of G. altavela, and D. hypostigma in aquaria, and (iii) newborns and adults of D. hypostigma. The results revealed potentially antibiotic-producing bacterial groups on the skin of rays from the natural environment, and some taxa with the potential to benefit ray health, mainly in rays from the natural environment, as well as possible pathogens to other animals, including fish and humans. Differences were observed between the G. altavela and D. hypostigma bacteria composition, as well as between the skin and stinger bacterial composition. The bacterial community associated with D. hypostigma changed with the age of the ray. The aquarium environment severely impacted the G. altavela bacteria composition, which changed from a complex bacterial community to one dominated almost exclusively by two taxa, Oceanimonas sp. and Sediminibacterium sp. on the skin and stinger, respectively.

Spatio-temporal evaluation of macro, meso and microplastics in surface waters, bottom and beach sediments of two embayments in Niterói, RJ, Brazil.

This study evaluated in the dry and rainy periods, the anthropogenic influence and the hydrodynamics in the distribution of plastic items in surface waters and bottom and beach sediments of the Jurujuba (Guanabara Bay, low and medium hydrodynamic) and Itaipu (oceanic region, high hydrodynamics) embayments; places of cultivation and extraction of mussels. Microplastics were 83% of the wastes collected, with a higher average concentration (138.41 items.kg-1) in beach sediments. High density polyethylene (HDPE) (38%), polypropylene (21%), and styrene (10%) were the most frequent polymers. There was no difference between the water and bottom sediment samples in the different embayments, in the studied periods, different from that observed in the beach sediment samples, with higher concentrations in the rainy season in Jurujuba. The results suggest that beach sediments are the best compartment to understand the dynamics of the distribution of plastic waste over time.

Microbial community shift under exposure of dredged sediments from a eutrophic bay.

Microbial communities occur in almost every habitat. To evaluate the homeostasis disruption of in situ microbiomes, dredged sediments from Guanabara Bay-Brazil (GB) were mixed with sediments from outside of the bay (D) in three different proportions (25%, 50%, and 75%) which we called GBD25, GBD50, and GBD75. Grain size, TOC, and metals-as indicators of complex contamination-dehydrogenase (DHA) and esterase enzymes (EST)-as indicators of microbial community availability-were determined. Microbial community composition was addressed by amplifying the 16S rRNA gene for DGGE analysis and sequencing using MiSeq platform (Illumina).We applied the quality ratio index (QR) to the GB, D, and every GBD mixture to integrate geochemical parameters with our microbiome data. QR indicated high environmental risk for GB and every GBD mixture, and low risk for D. The community shifted from aerobic to anaerobic profile, consistent with the characteristics of GB. Sample D was dominated by JTB255 marine benthic group, related to low impacted areas. Milano-WF1B-44 was the most representative of GB, often found in anaerobic and sulfur enriched environments. In GBD, the denitrifying sulfur-oxidizing bacteria, Sulfurovum, was the most representative, typically found in suboxic or anoxic niches. The canonical correspondence analysis was able to explain 60% of the community composition variation and exhibit the decrease of environmental quality as the contamination increases. Physiological and taxonomic shifts of the microbial assemblage in sediments were inferred by QR, which was suitable to determine sediment risk. The study produced sufficient information to improve the dredging plan and management.

Dredging Activities Carried Out in a Brazilian Estuary Affect Mercury Levels in Swimming Crabs.

(1) Although suffers from intense pollution inputs, Guanabara Bay, the most socioeconomically and environmentally important estuary in Rio de Janeiro, Brazil, is still home to a diverse fauna, including several fish and crab species consumed by humans. The bay presents high sedimentation rates and sediment contamination, further aggravated by dredging processes carried out in recent years. In this context, this study aimed to verify the effect of the dredging process on total mercury (THg) concentrations at Guanabara Bay through swimming crab assessments sampled before (2016), during (2017), and after (2018) the dredging process, and mainly, if the detected concentrations can be harmful to consumer health; (2) Methods: Swimming crab samplings were carried out at the same time and sampling points in 2016, 2017 and 2018 and the total Hg was determined using a Direct Mercury Analyzer (DMA-80, Milestone, Bergamo, Italy); (3) Results: Increased Hg concentrations were observed during the dredging process, decreasing to lower values, close to the initial concentrations, at the end of the process. Some of the investigated abiotic factors favor Hg dynamics in the aquatic environment, while others were positively altered at some of the assessed sampling areas at the end of the dredging process; (4) Conclusions: Although crab Hg levels were below maximum permissible limits for human consumption, it is important to note that these animals are significantly consumed around Guanabara Bay, which may lead to public health issues in the long term.

New bacterial and archaeal lineages discovered in organic rich sediments of a large tropical Bay.

The nutrient and oxygen gradient present in marine sediments promotes high levels of microbial diversity. We applied metagenomics and biogeochemical tools to analyze microbial communities in different sediment depths (0-4 m below sea floor, mbsf) from Guanabara Bay, Brazil, a brackish tropical ecosystem with a history of massive anthropogenic impacts, and a largely unknown sediment microbial diversity. Methanogens (e.g. Methanosarcinales, Methanomicrobiales) were more abundant at 1 mbsf, while sulphate-reducing microbes (Desulfurococcales, Thermoprotales, and Sulfolobales) were more abundant at deeper layers (4 mbsf; corresponding to 3 K Radiocarbon years before present, Holocene Epoch). Taxonomic analyzes and functional gene identification associated with anaerobic methane oxidation (e.g. monomethylamine methyltransferase (mtmB), trimethylamine methyltransferase (mttB) and CO dehydrogenase/acetyl-CoA synthase delta subunit) and sulfate reduction indicated the dominance of Campylobacteria (Sulfurimonas) at deeper sediment layers. Gene sequences related to assimilation of inorganic sulfur increased with depth, while organic sulfur related sequences decrease, accompanying the clear reduction in the concentration of sulfur, organic carbon and chla torwards deeper layers. Analyzes of metagenome assembled genomes also led to the discovery of a novel order within the phylum Acidobacteriota, named Guanabacteria. This novel order had several in silico phenotyping features that differentiate it from closely related phylogenetic neighbors (e.g. Acidobacteria, Aminicenantes, and Thermoanaerobaculum), including several genes (carbon monoxide dehydrogenase, CO dehydrogenase/CO-methylating acetyl-CoA synthase complex subunit beta, heterodisulfide reductase, sulfite exporter TauE/SafE family protein, sulfurtransferase) that relevant for the S and C cycles. Furthermore, the recovered Bathyarchaeota genome SS9 illustrates the methanogenic potential in deeper sediment layer.

A poluição na Baía de Guanabara e a emergência da pauta ambiental no jornal O Globo / The pollution in Guanabara Bay and the emergence of the environmental agenda in O Globo newspaper / La contaminación en la Bahía de Guanabara y el surgimiento de la agenda ambiental en el periódico O Globo

Este artigo busca apresentar de que formas e sob quais circunstâncias a Baía de Guanabara pôde emergir como importante pauta jornalística ambiental. Analisando matérias do jornal O Globo entre as décadas de 1940 e 1970, período crucial para se entender a poluição daquele ambiente, identificamos a transformação de um referencial idílico da baía para a representação de um lugar de perigo. Nesse sentido, exploramos a importância que a saúde humana adquire para que esta pauta ambiental atingisse um alto patamar de noticialização, semelhantes aos níveis atuais. Refletimos, ainda, sobre as maneiras pelas quais a pauta ambiental pode ser construída, longe de síndromes comuns a esta especialidade jornalística, mas associada a marcos teóricos importantes do campo, como a imprescindibilidade do ativismo ecológico e a necessidade de ampliação do enfoque noticioso e abarcamento de conhecimentos de povos tradicionais.

This article seeks to present in which ways and circumstances Guanabara Bay could emerge as an important environmental journalistic agenda. Analyzing articles from the O Globo newspaper between the 1940s and the 1970s, a crucial period to understand the pollution of the bay, we identified the changes of an idyllic reference point of the bay to represent a place of danger. In this sense, we explore the importance that human health acquires for the environmental agenda of the bay to reach levels of reporting similar to the current ones. We also reflect about how the environmental agenda can be built away from syndromes common to this journalistic field, but associated with important theories in the field, such as the indispensability of ecological activism and the need to expand the news focus and to encompass the knowledge of traditional people.

Este artículo busca presentar de qué maneras y bajo qué circunstancia la Bahía de Guanabara podría emerger como una importante agenda periodística ambiental. Analizando artículos del periódico O Globo entre las décadas de 1940 y 1970, un período crucial para comprender la contaminación de la bahía, identificamos la transformación de un punto de referencia idílico de la bahía para representar un lugar de peligro. Em este sentido, exploramos la importancia que adquiere la salud humana para que la agenda ambiental de la bahía alcance niveles de informes similares a los actuales. También reflejamos las formas em que la agenda ambiental se puede construir a partir de síndromes comunes a este campo periodístico, asociada con importantes teorías en el campo, como la indispensabilidad del activismo ecológico y la necesidad de expandir el enfoque de las noticias y abarcar el conocimiento de las personas tradicionales.

Sedimentary record of hydrocarbons and sewage inputs from a highly populated region in South-Eastern Brazil.

The environmental impacts of the urban expansion in Rio de Janeiro was evaluated based on the historical accumulation of black carbon (BC), aliphatic (AHs) and aromatic hydrocarbons (PAHs) and sterols in a sediment core retrieved from Botafogo Cove. BC related to oil combustion sources increased significantly since the 1990s. AHs were associated with petroleum inputs and revealed a high level of contamination. Multivariate statistical methods (a Principal Component Analysis associated with a linear multiple regression - PCA/LMR) applied to PAHs suggests changes in the sources in recent years. This can be ascribed to a reduction in pyrogenic emissions over the last four decades and to an increase in petrogenic inputs since the 1990s. The sterol dinosterol registered the increased eutrophication over the last three decades, but the sewage marker coprostanol was present at relatively low concentrations (0.40 to 1.16 µg g-1) probably caused by enhanced bacterial activity in the sediment.