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The Intermediate Western Boundary Current (IWBC) transports Antarctic Intermediate Water across the Vitória–Trindade Ridge (VTR), a seamount chain at ~20°S off Brazil. Recent studies suggest that the IWBC develops a strong cyclonic recirculation in Tubarão Bight, upstream of the VTR, with weak time dependency. We herein use new quasi-synoptic observations, data from the Argo array, and a regional numerical model to describe the structure and variability of the IWBC and to investigate its dynamics. Both shipboard acoustic Doppler current profiler (ADCP) data and trajectories of Argo floats confirm the existence of the IWBC recirculation, which is also captured by our Regional Oceanic Modeling System (ROMS) simulation. An “intermediate-layer” quasigeostrophic (QG) model indicates that the ROMS time-mean flow is a good proxy for the IWBC steady state, as revealed by largely parallel isolines of streamfunctionand potential vorticity; ascatter diagram also shows that the IWBC is potentially unstable. Further analysis of the ROMS simulation reveals that remotely generated, westward-propagating nonlinear eddies are the main source of variability in the region. These eddies enter the domain through the Tubarão Bight eastern edge and strongly interact with the IWBC. As they are advected downstream and negotiate the local topography, the eddies grow explosively through horizontal shear production.

This study presents the first high-resolution speleothem-based hydrological reconstruction for much of the last 2.7 kyr in the central-western Mediterranean. The paleohydrological information comes from a combination of five U-Th dated stalagmites from two Mallorca island caves. Interpretations are based on high-resolution records of δ18O, δ13C and trace element analyses combined with information from mineralogical X-ray diffraction, fabrics and morphological features, and cave monitoring data. None of the studied stalagmites cover the whole 2.7 kyr period but they provide sufficient overlap to replicate most of the discussed climatic intervals with the exception of the Medieval Climate Anomaly (MCA), which is represented by a hiatus. Taking into account the results of five years farmed calcite collected in glass plates and cave environmental parameters, we argue that main patterns in the stalagmite geochemical records are mostly controlled by changing rates of prior calcite precipitation (PCP) that respond to hydrological changes in the region. We apply a principal component analysis to the stalagmite geochemical data set and a composite δ18O record to obtain a robust regional hydrological record. This record supports wet conditions for the early Roman Period (RP), the first half of the Early Middle Ages (EMA) and the Little Ice Age (LIA), and drier conditions for the late RP, the late EMA and the entire MCA. These results are discussed in the context of other climatic and oceanographic records from the region including paleo North Atlantic Oscillation (NAO) records. This ocean-atmosphere approach suggests complex non-stationary climate patterns for the last 2.7 kyr, including the occurrence of both wet-warm and wet-cold intervals and underlying the complex interaction of factors controlling climate evolution in the region. Overall, positive (negative) NAO phases appear coincident with drier (wetter) conditions for all the examined period at decadal time-scales. ISSN:0277-3791

The Cananéia-Iguape estuarine–lagoon complex (São Paulo state, Brazil) is a natural laboratory to study metal binding by humic substances (HS) in subtropical settings. This transitional environment is evolving into a freshwater environment due to water input from the Ribeira River, funneled through the Valo Grande Canal (Iguape). Past mining activities in the Ribeira River basin and maritime traffic are suspected to be potential sources of trace metals in the system. In this study, the trace metal contents of Free Humic Acids (FHA), Bound Humic Acids (BHA), and Fulvic Acids (FA) extracted from sedimentary organic matter were investigated. Moreover, the sources of HS were traced using their stable carbon isotope compositions and C/N ratios. The results suggested a mixed marine–terrestrial source of FHA, BHA, and FA. Copper and Cr were the most abundant trace metals bound to HS. On average, Cu showed concentrations of 176, 115, and 37.9 μg g−1 in FHA, BHA, and FA, respectively, whereas Cr showed average concentrations of 47.4, 86.3, and 43.9 μg g−1 in FHA, BHA, and FA, respectively. Marine FHA showed the highest binding capacity for trace metals, whereas terrestrial FA derived from the decay of mangrove organic matter showed the lowest binding capacity.

The worldwide evidence of human activities on the environment led the scientific community to recognize a new geologic time unit known as the "Anthropocene." Since the twentieth century, urbanization and industrialization needs driven by population and economic growth have impacted several ecosystems including the estuaries. To assess the contamination, provenance, and fluxes of trace elements (As, Cr, Cu, Ni, Pb, Sc, V, and Zn) over the last century, a geochemical and chemometric technique was employed in sediment cores of an industrial and port region of international importance, the Santos and São Vicente Estuarine System (SSVES). The results indicated low contamination, with the highest enrichment factors (EFs) for Cu (EF = 3.1), Pb (EF = 2.7), Zn (EF = 2.4), and As (EF = 2.3) found next to the harbor area. The Pre-industrial records confirm the relatively high concentrations of As and its naturally enriched occurrence on the Brazilian shelf. Sediment accumulation rates and trace element fluxes showed a general increase over the years, since the early 1960s, associated with the "Great Acceleration" of the mid-twentieth century. These alterations are human-induced and include urbanization and industrialization. Nonetheless, as the contents and enrichment of trace elements indicate that the region is not severely polluted, we hypothesize that the contamination in the SSVES is likely related to the drainage and erosion of the urbanized adjacent area, rather than direct disposal of inorganic contaminants from the industrial activity.

Many species drive the diversity of ecosystems by adding structural complexity to the environment. In coral reefs, stony corals act as habitat-forming species, increasing niche availability for other organisms. Some coral species play key roles as reef builders due to their abundance or morpho-functional characteristics. Thus, changes in the distributions of these species can entail cascading effects in entire ecosystems. With climate change, many coral species are experiencing shifts in their distributions, threatening the preservation of coral reefs. Here, we projected the current and future distributions of three key reef builders of the Atlantic (Mussismilia hispida, Montastraea cavernosa, and the Siderastrea complex) under three relative concentration pathway scenarios: the most optimistic, the most pessimistic and one moderate scenario (RCP2.6, 4.5, and 8.5). Our models revealed that all the above species will undergo habitat loss in the future (2100) in the most pessimistic scenario, although new areas could become suitable, including regions in the eastern Atlantic Ocean. Additionally, when considering only its actual range of occurrence, M. hispida will lose habitats under all future scenarios. Moreover, in some regions of both the Tropical Northwestern Atlantic (TNA) and the Brazilian coast, these three species could disappear, with detrimental consequences for the associated communities. We highlight the need for an urgent change of course to guarantee functional reefs in the Atlantic in the future.

There is a considerable gap linking human dimensions and marine ecosystem services with Sustainable Development Goals, and one of these issues relate to differing perspectives and ideas around concepts of human development. There is also a lack of contemporary evaluations of coastal communities from developing nations under the lens of wellbeing and social vulnerability indexes. This study contributes to that discussion by presenting an analysis of Brazilian coastal municipalities, based on two indexes: The Social Vulnerability Index (SVI) and the Municipal Human Development Index (MHDI). These indicators intend to map some aspects of social well-being and development in the Brazilian territory under different perspectives. MHDI illustrates the average population conditions in a certain territory for humans to thrive, while the SVI points more specifically to the lack of assets necessary for wellbeing in a territory. The main aims are to map inequalities between coastal municipalities based on these two indexes and to provide a critical view reinforcing the importance of also considering natural capital as a key issue for wellbeing. Both indexes were developed with data from the Brazilian Institute of Geography and Statistics Census of 2010, the most recent one available for municipalities. Overall, 65.9 and 78% of a total of 387 Brazilian coastal municipalities assessed were ranked below SVI and MHDI country average values, respectively. Both indexes indicated higher human development conditions in Southern municipalities than in Northern ones, especially for income and education conditions, also showing large heterogeneity of discrepancies among and within regions. The importance of combined approaches for local socioeconomic wellbeing improvements, as measured by the MHDI and the SVI, and natural capital optimization seems essential for improvements in coastal communities’ quality-of-life conditions.

In tide-dominated estuaries, maximum-turbidity zones (MTZs) are common and prominent features, characterized by a peak in suspended-sediment concentration (SSC) associated with estuarine processes. The Brazilian Amazon coast includes many estuaries, experiencing macrotidal conditions. MTZs are expected to occur and are crucial for sediment delivery to the longest continuous mangrove belt of the world. The area is under influence of the Amazon River plume (ARP), the main SSC source, as local rivers do not deliver substantial sediment supply. To assess the processes that allow the ARP to supply sediment to the estuaries and mangrove belt along the Amazon coast, the results from previous individual studies within five Amazon estuaries (Mocajuba, Taperaçu, Caeté, Urumajó and Gurupi) were compared with regards to SSC, salinity, morphology and tidal propagation. This comparison reinforces that these estuaries are subject to similar regional climate and tidal variations, but that their dynamics differ in terms of distance from the Amazon River mouth, importance of the local river sediment source, and morphology of the estuarine setting. The Urumajó, Caeté and Gurupi are hypersynchronous estuaries where perennial, classic MTZs are observed with SSC &gt, 1 g·L−1. This type of estuary results in transport convergence and MTZ formation, which are suggested to be the main processes promoting mud accumulation in the Amazonian estuaries and therefore the main means of mud entrapment in the mangrove belt. The Mocajuba and the Taperaçu estuaries showed synchronous and hyposynchronous processes, respectively, and do not present classic MTZs. In these cases, the proximity to the ARP for the Mocajuba and highly connected tidal channels for the Taperaçu estuary, assure substantial mud supply into these estuaries. This study shows the strong dependence of the estuaries and mangrove belt on sediment supply from the ARP, helping to understand the fate of Amazon River sediments and providing insights into the mechanisms providing sediment to estuaries and mangroves around the world, especially under the influence of big rivers.

The dynamics of estuarine systems is sensitive to changes in its forcing conditions, including the morphology of its inlets. Coastline retraction, which may be induced by climate change, can result in modifications of estuarine inlet morphology. Through the use of a validated numerical model, we evaluate the effects of the opening of a new inlet on a tide-dominated estuary (Caravelas estuary, Brazil). During the last decades, shoreline retraction and the breach of an internal drainage channel led to the formation of a new inlet that became the main estuarine channel. The morphological changes of the estuary resulted in changes to its estuarine processes, including the general increase in the influence of the tide on the system and changes to its asymmetry. Internal channels that interconnect adjacent estuaries present great changes caused by the morphological alterations, not only in the magnitude of the processes but also in the resulting net transport direction. The increase in the water flow caused by the opening of the channel leads to an increase in the amount of water and materials carried toward the estuary. The changes presented here for the Caravelas estuarine system and the possible implications for the functioning of such systems demonstrate the importance of evaluating morphological aspects in relation to their use and management.

Explosive volcanic eruptions are the largest non-anthropogenic perturbations for Earth’s climate, because of the injection of sulfate aerosols into the stratosphere. This causes significant radiation imbalances, resulting in surface cooling for most of the globe. However, despite its crucial importance for Antarctic ice sheet mass balance, the response of the Southern Ocean to eruptions has yet to be understood. After the eruption of Mt. Pinatubo in 1991, much of the Southern Ocean cooled; however, off the Antarctic Peninsula a warming of up to 0.8 °C is found in the observations. To understand the physical mechanisms associated with this counter-intuitive response, we combine observational analysis from the Mt. Pinatubo eruption with the Last Millennium Ensemble (850–1850) conducted with the Community Earth System Model. These results show not only that the observed warming off the Peninsula following the Mt. Pinatubo eruption is consistent with the forced response to low-latitude eruptions but further, that this warming is a response to roughly 16% weakening of subsurface Weddell Gyre outflow. These changes are triggered by a southward shift of the Southern Hemisphere polar westerlies (∼2°latitude). Our results suggest that warming induced by future volcanic eruptions may further enhance the vulnerability of the ice shelves off the Antarctic Peninsula.

Polycyclic aromatic hydrocarbon (PAH) concentrations were determined in four dated sediment cores collected in mud depocenters of the southern Brazilian continental shelf. Core dating results covered the interval between 1925 and 2017. The total PAH concentrations (ΣPAHs) ranged from 44.69 ng g−1 to 305.43 ng g−1 and were similar between the analysed cores. Fine-grained sediments and total organic carbon (TOC) results did not correlate with the ΣPAHs, indicating that the variations in PAH concentrations are mostly related to variations in sources and emissions. PAH source appointment indicated a high input of a natural compound (perylene) and the predominance of anthropogenic PAHs from coal, biomass, and fuel combustion. Alkylated PAHs presented high contributions throughout all cores. The historical deposition of PAHs was associated with different periods of the socio-economic and industrial development of near coastal cities and reflected very well the history of coal production and consumption in the southern region of Brazil. The low levels of ΣPAHs before 1945 in all analysed cores may be related to the beginning of the industrialization process and the lower urbanization degree in the region. Between 1945 and 1965, the gradual ΣPAHs increase reflects the establishment and enlargement of the southern Brazilian industrial sector. The interval between 1965 and 1990 corresponded to the highest ΣPAHs in three of the four analysed cores. After 1990, a relative decrease in the ΣPAHs was observed in most cores and may be related the multiple cuts of incentives to the industrial usage of coal, as well as to Brazil's efforts in environmental regulation for coal extraction and consumption.

This study aims to investigate the spatial variability of surficial sedimentation processes on a large sector of the Brazilian shelf by using echo-character mapping. To reach this goal, almost 3200 km of high-resolution seismic lines collected with a 3.5 kHz Chirp source are compared with surficial sediment-related distribution maps. Based on seismic characteristics, such as sharpness, amplitude, and continuity of sub-bottom reflections, six echo types were identified in the study area. These echo types were grouped into two main classes according to the nature of seafloor morphology. Class 1 is characterized by flat-bottom echoes with a variable amplitude of reflections and acoustic penetration. This class is predominantly found on the inner and middle shelves. Class 2 consists of irregular seafloor morphologies and is classified based on the occurrence of internal reflections and relief variations. This class is mainly found on the outer shelf. The distribution of echo types and associated surficial sediment maps exhibit three main shelf domains: inner, middle, and outer. The echo types are mostly controlled by the influence of along-shelf currents, as well as by mid-shelf fronts associated with the entrance of cold-water tongues under changing wind conditions and upwelling phenomena. Whereas the inner shelf is mainly affected by variable wind-driven currents, the outer shelf is more persistently influenced by the southwestward movement of the Brazil Current. Between these areas, the middle shelf is affected by seasonal intrusions of the South Atlantic Central Water and northward extensions of the Brazilian Coastal Current. The studied area can be considered a case model for a shelf driven by hydrodynamic processes., This research was supported by grants (2010/06147–5, 2016/08029–6, and 2016/24251–0) from the São Paulo Research Foundation (FAPESP). We thank the NAP-GEOSEDEX Program for providing the data. We thank the crew and researchers who participated in the Alpha Crucis cruises. F.J. Lobo acknowledges the Brazilian program "Ciência sem Fronteiras" funded by CNPq, enabling him to conduct several research stages as "Pesquisador Visitante Especial" at the Instituto Oceanográfico, Universidade de São Paulo, under project number 401041/2014–0. Dr. Deniz Cukur and one anonymous reviewer are also greatly appreciated for their constructive comments on the original draft. The authors also acknowledge IHS Markit for providing the software Kingdom Suite under the Educational Grant Program.

Polycyclic aromatic hydrocarbons (PAHs) were measured in 32 surface sediment samples collected around three cities (Barcarena, Belem, and Santana) located on the coast of the Brazilian Amazon. The concentration of total PAHs ranged from lower than detection limit to 33,101 ng g-1 in a sample from Barcarena and was related to a large aluminum industrial complex and port activities. In Belem, which is the most populated area in the Amazon region, PAHs were probably derived from untreated sewage discharge and inputs from a large municipal landfill. Pyrogenic PAHs were predominant in both cities, with a smaller contribution of petrogenic PAHs. Low alkylated PAH levels may be associated with small boats and ship traffic. Santana had low total PAH concentrations, with a predominance of unusual alkylated PAHs, probably related to diagenetic transformations of organic matter in the sediment. In general, PAH concentrations in the samples were low and may reflect baseline levels for this Amazon estuarine system.

Made available in DSpace on 2021-06-25T10:32:42Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-09-01 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Recent studies have shown that the effectiveness of establishing Marine Protected Areas (MPAs) is threatened by toxic effects of contaminants. São Paulo is the most economically developed state of Brazil, and its coast is protected by a system of MPAs, including the North Shore Marine Protected Area (NSMPA). The present study provides a first assessment of sediment quality in NSMPA and two reference sites. Concentrations of arsenic (As), metals (Al, Fe, Cd, Cr, Cu, Ni, Pb, and Zn) and polycyclic aromatic hydrocarbons (PAHs) and its sources were determined. Comparisons with sediment quality guidelines indicated low contamination, as confirmed by the Geoaccumulation Index, which classified the results as background levels. Whole-sediment exposures of the amphipod Tiburonella viscana were performed to estimate possible acute effects, but samples exhibited no toxicity. The results presented in this study represent a baseline for further monitoring programs of MPAs, supporting conservation actions of management plans. São Paulo State University (UNESP), Praça Infante Dom Henrique, s/n Institute of Marine Sciences (LABOMAR) Federal University of Ceará (UFC), Av. da Abolição, 3207 Oceanographic Institute (IOUSP) University of São Paulo (USP), Praça do Oceanográfico, 191 Department of Chemistry Federal University of Ceará (UFC), Av. Humberto Monte s/n Department of Geochemistry Fluminense Federal University (UFF) São Paulo State University (UNESP), Praça Infante Dom Henrique, s/n CAPES: 001 FAPESP: 2013/15482-0 CNPq: 308533/2018-6 CNPq: 311609/2014-7 CNPq: 455280/2014-2

The vertical export of particulate organic carbon (POC) is a key component of the oceanic biological pump, which regulates the distribution of elements associated with primary production in the upper euphotic zone. To better understand how oceanic biogeochemical processes will respond in climate change scenarios, it is necessary to comprehend the mechanisms that regulate the magnitude and variations of POC flux among distinct oceanic domains, including the boundaries between continental margins and oceanic basins. This work is a first assessment of particle flux over the South Brazil Bight continental slope, a tropical western boundary system dominated by the Brazil Current. Total mass flux, and specific carbon, nitrogen and biogenic silica fluxes were measured periodically by two sediment traps installed at 450 m deep over the 900 m isobath, and at 750 m deep over the 2000 m isobath, from November 2016 to September 2017. Due to strong contribution of advected particles, high and extremely irregular fluxes were registered at the 900 m isobath site (mean = 1.1 g m-2 d− 1, stand. dev. ± 2.9 g m-2 d-1). The captured material suggests this sediment trap was affected by turbidity flows, which precludes the estimation of the biological pump contribution over this isobath. Over the 2000 m isobath, POC flux (3.7 mg m-2 d-1; ±2.5 mg m-2 d− 1) followed the seasonal pattern of primary production measured by satellite. POC flux was strongly correlated with biogenic silica content (r = 0.79; p

Organic biomarkers, as aliphatic hydrocarbons, are present in sedimentary organic matter and have been largely applied to the evaluation of recent environmental changes in the marine environment around the globe, including the Antarctic continent. Five sediment cores were taken in the Admiralty Bay, South Shetland Archipelago, Antarctica to evaluate changes in the signature of aliphatic hydrocarbons such as n-alkanes (n-C10 to n-C40) and isoprenoids as pristane and phytane, over the last decades. The total n-alkanes concentration ranged from 0.17 to 1.67 μg g−1 (mean = 0.74 ± 0.42) which is considered low and similar to pristine sediments. Aliphatic hydrocarbons present in the sedimentary pool came mostly from terrestrial sources as Antarctic lichens and mosses, and from marine sources as the macroalgae forest debris and emergent macrophytes. Anthropogenic inputs of aliphatic hydrocarbons (e.g., petroleum and their by-products) may be neglected based on the multi-proxy approach used to distinct sources of these organic compounds. In general, no significant changes in the sources of aliphatic hydrocarbons were observed along the sediment cores; however, an increased aliphatic hydrocarbons input registered between 1975 and 1992 may be related to the increase in meltwater runoff and the relatively high abundance of marine producers more adapted to increased sea temperatures.

Anthropogenic climate forcing will cause the global mean sea level to rise over the 21st century. However, regional sea level is expected to vary across ocean basins, superimposed by the influence of natural internal climate variability. Here, we address the detection of dynamic sea level (DSL) changes by combining the perspectives of a single and a multi-model ensemble approach (the 50-member CanESM5 and a 27-model ensemble, respectively, all retrieved from the CMIP6 archive), under three CMIP6 projected scenarios: SSP1-2.6, SSP3-7.0 and SSP5-8.5. The ensemble analysis takes into account four key metrics: signal (S), noise (N), S/N ratio, and time of emergence (ToE). The results from both sets of ensembles agree in the fact that regions with higher S/N (associated with smaller uncertainties) also reflect earlier ToEs. The DSL signal is projected to emerge in the Southern Ocean, Southeast Pacific, Northwest Atlantic, and the Arctic. Results common for both sets of ensemble simulations show that while S progressively increases with increased projected emissions, N, in turn, does not vary substantially among the SSPs, suggesting that uncertainty arising from internal climate variability has little dependence on changes in the magnitude of external forcing. Projected changes are greater and quite similar for the scenarios SSP3-7.0 and SSP5-8.5 and considerably smaller for the SSP1-2.6, highlighting the importance of public policies towards lower emission scenarios and of keeping emissions below a certain threshold.

Anthropogenic activities have impacted the coastal region of Brazil. In the Paranagua estuarine complex (PEC), Cananeia-Iguape estuarine-lagoon complex (CIELC), and Santos-Sao Vicente estuarine complex (SSVEC), such activities occur across differing scales. In these estuaries, the concentrations of mercury (Hg) and stable nitrogen isotopes (δ15N) were investigated in sediments and marine organisms including benthic macrofauna, fish and cetaceans. Hg bioconcentration occurred primarily in cetaceans, polychaetes and molluscs, and reflects the impact of anthropogenic activities in the regions studied (PEC and SSVEC > CIELC). Bioaccumulation occurred in most of the studied specimens, but biodilution of Hg was observed in the trophic webs of SSVEC and CIELC. Despite measuring lower Hg levels than in studies carried out in the northern hemisphere, the results highlight potential concerns for public and environmental health in these highly productive coastal regions in the southwestern Atlantic which are important for fishing and various economic activities.

The celebration of the International Polar Year in 2007 remarked the necessity to better monitor the polar regions. Moreover, the H2020 “Operational Network of Individual Observation Nodes” (ONION) project analyzed and proposed an overall EU strategy and technical guidelines to develop and implement innovative Earth Observation concepts in the time frame 2021-2027. The top priority that was identified was the Maritime Weather Forecast, and in particular the Arctic sea ice monitoring use-case. Currently, those needs have been addressed with remote sensing satellites or in-situ instruments. However, in-situ instruments often sink or crash with ice blocks. Additionally, these instruments are isolated, making challenging its deployment and the data retrieval, using LEO satellite communications (e.g. Iridium, OrbComm). This also poses a problem in terms of modularity and flexibility, since sensors rely on proprietary communication systems. This work proposes a modular and cost-effective solution to this problem applying the paradigm of the Internet of Things to this context. Particularly, Long Range (LoRa) is one of the most frequently used and efficient technologies that also ensures long ranges. As part of the presented work, a satellite constellation is proposed, analyzed to cover the Arctic region. The maximum number of sensors simultaneously using the LoRa technology is also evaluated.

Bathymetry (seafloor depth), is a critical parameter providing the geospatial context for a multitude of marine scientific studies. Since 1997, the International Bathymetric Chart of the Arctic Ocean (IBCAO) has been the authoritative source of bathymetry for the Arctic Ocean. IBCAO has merged its efforts with the Nippon Foundation-GEBCO-Seabed 2030 Project, with the goal of mapping all of the oceans by 2030. Here we present the latest version (IBCAO Ver. 4.0), with more than twice the resolution (200 × 200 m versus 500 × 500 m) and with individual depth soundings constraining three times more area of the Arctic Ocean (∼19.8% versus 6.7%), than the previous IBCAO Ver. 3.0 released in 2012. Modern multibeam bathymetry comprises ∼14.3% in Ver. 4.0 compared to ∼5.4% in Ver. 3.0. Thus, the new IBCAO Ver. 4.0 has substantially more seafloor morphological information that offers new insights into a range of submarine features and processes; for example, the improved portrayal of Greenland fjords better serves predictive modelling of the fate of the Greenland Ice Sheet., Measurement(s)depthTechnology Type(s)digital curationFactor Type(s)geographic locationSample Characteristic - Environmentocean floorSample Characteristic - LocationArctic Ocean Machine-accessible metadata file describing the reported data: 10.6084/m9.figshare.12369314

The early Paleogene sedimentary record of the Sao Paulo Plateau holds the key to understanding the timing and mechanisms of the onset of Atlantic oceanic circulation, with implications for ocean – climate feedback systems. The timing and evolution of South Atlantic Ocean connectivity remain poorly understood, hindering a full understanding of modern circulation mechanisms. In this work, we develop an improved magnetostratigraphic age model for the late- Cretaceous to Eocene sedimentary record of Deep-Sea Drilling Project (DSDP) Site 356, located on the São Paulo Plateau at the edge of the Rio Grande Rise. The model constrains the timing of the beginning of Atlantic Ocean circulation, as the last obstacle to a connected Atlantic was removed. We use the age model to quantify sedimentary rates, and correlate with rock magnetic and published geochemical data to explore links between ocean current rearrangement and climatic anomalies. We find that periods characterized by variations in the magnetic properties of sediments and sedimentation anomalies in the Sao Paulo Plateau are reflected in carbon isotope events, supporting a possible link between ocean circulation and hyperthermal events.

In this study, we combine the use of Metal/Metal ratios of 134 sediment samples with multivariate analysis to provide the first geochemical mapping of a large subtropical estuary influenced by one of the largest grain-shipping terminals of South America. Together with grain-size data, the results allowed us to efficiently map the different sectors of the estuarine complex, defining its geochemical faciology. Also, potassium-related ratios appeared to be reliable proxies for the identification of point sources of terrigenous sediments. Since there was no evidence of widespread trace metal contamination, the results here presented can be used as a baseline for the area.

This paper aims to improve the understanding of the marine sedimentation of the continental shelf and upper slope off southeast (SE) Brazil during the 20th century through the study of the deposition of natural radionuclides and its relationships with other sedimentological variables in a large set of sediment cores obtained during several oceanographic cruises. The main results of this study were the determination of sedimentation rates (0.49–3.73 cm yr−1) and its geographic distribution in the area. Together with 226Ra, mud, and carbonate content data, a picture emerged of a shelf and upper slope mostly dominated by lithoclastic sediments with a spatially heterogeneous grain size distribution, inputs of allochthonous sediments, and the presence of mid-outer shelf mud depocenters. Based on the age reconstruction of the cores, it was established that the area underwent no significant variations in sedimentation patterns during the period sampled by the cores, which corresponded to the last century. Nevertheless, there were clear geographical differences within the region; thus, the area was divided into sectors suggested by the assessed variables. The southern sector is marked by the presence of mud depocenters with high sedimentation rates and 226Ra levels connected to the Brazil Coastal Current (BCC) flow. The northern sector presents irregularly distributed sediments and modern contribution from processes associated with the Brazil Current (BC) and the exchange of materials with nearby coastal systems. The central sector functions as an interface between the processes observed in the southern and both sectors. The results highlight the need to reassess the prevalence of the reworking of Pleistocene sediments and the lack of current sediment sources in the area.

We present enigmatic toroidal carbonate concretions retrieved from 700 m water depth from two sites in the upper plateau of the Rio Grande Rise. The concretions have a diameter of ~15 cm and a central hole of ~5 cm, and were observed on top of loose bioclastic sand over an area of ~30 m2 at 0.5–1.5 m from one another. They consist of brown, porous, bioclastic grainstone, lacking internal structures. Grains consist of sand (

We report a study of the magnetic stratigraphy and the anisotropy of isothermal remanent magnetization of Pliocene sediments from International Ocean Discovery Program (IODP) Site U1467 drilled in the Maldives platform (Indian Ocean) during Exp. 359. Magnetic stratigraphy gives a precise record of geomagnetic reversals of the early Pliocene from approximately 5.3 Ma to 3.1 Ma providing a detailed age model in an interval where the biostratigraphic record is scarce. We use the anisotropy of isothermal remanent magnetization (AIRM) to investigate the statistical orientation of fine magnetic particles and provide data on the strength and direction of bottom currents during the early Pliocene. The strength of bottom currents recorded by the AIRM, shows a prominent increase at the top of Chron C3n.1n (about 4.2 Ma), and the current direction (NE - SW) is consistent with that of modern instrumental measurements. Since bottom currents in the Maldives are driven by the monsoon, we speculate that the 4.2 Ma increase of bottom currents could mark the onset of the present-day setting, probably related to the coeval uplift phase of the Himalayan plateau. IODP-Italia University of Urbino (DiSPeA)

Total phosphorus (TP) records reflect variations in input and burial of organic matter (OM) in coastal and shelf sediments . At Antarctic regions , TP levels are often derived from natural sources; however, with emergent human pressure at these regions, anthropogenic sources of TP may play an important role. At the Antarctic Peninsula , Admiralty Bay attracts great scientific and touristic interest, especially during austral summer months, thus being vulnerable to human activities. Currently, only scarce spatial distributions of TP are available for this key region, whereas no vertical distributions have been determined. To fill this gap, we investigated short ( sediment cores in ten areas along Admiralty Bay for TP contents. We produced the first TP vertical distributions and established site-specific background values (from 492 ± 13 to 932 ± 17 μg g −1 ), which are related to hydrodynamics, sedimentology , and natural inputs of P. We observed a gradual surface TP enrichment at all sites, mainly due to input of fresh OM. Benefiting from our background values, we employ the Phosphorus Pollution Index (PPI) to assess possible human impacts . Generally, the increase of PPI suggests natural inputs of P. However, PPI ≥ 1.3 found at the nearby Comandante Ferraz Research Station (Brazil) can be linked to recent (past 2–3 decades) treated sewage inputs in Martel Inlet. We suggest PPI as a proxy for preliminary assessments of anthropogenic impacts in coastal Antarctic regions experiencing increased human pressure.

Made available in DSpace on 2022-04-29T08:35:01Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-12-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) The evaluation of anthropogenic pressures in marine environments commonly involves sediments, water and marine biota. However, the evaluation of the quality of the beach sediment and sediments from shallow areas are scarce compared to sediments from deeper areas in environmental assessment studies. In this study polycyclic aromatic hydrocarbons and linear alkylbenzenes were assessed in sediments from shallow areas of the São Sebastião channel, southeastern Brazil. The channel is part of the Marine Protected Area of the Northern Coast of São Paulo State besides holds the largest petroleum terminal in South America further than three sewage outfalls. Despite the concentrations of these contaminants in the sediments were relatively low compared to those found in the sediments from deeper areas of the channel, suggesting low toxicity of the beach sediments, the contamination reflected the pattern of the sediments of the São Sebastião channel. Instituto de Biociências Universidade Estadual Paulista, Campus do Litoral Paulista, São Vicente Instituto Oceanográfico da Universidade de São Paulo, Praça do Oceanográfico, 191 Centro de Aquicultura Universidade Estadual Paulista Instituto de Biociências Universidade Estadual Paulista, Campus do Litoral Paulista, São Vicente Centro de Aquicultura Universidade Estadual Paulista FAPESP: 2016/17189-7.

This paper describes differences between Medieval Climate Anomaly (MCA) and present-day temperatures in the area composed of the Antarctic Peninsula, southern Patagonia, and the surrounding southern oceans. The investigation is conducted with the simulation results from the Community Earth System Model Last Millennium Ensemble (CESM-LME) considering the impact of each natural (volcanic activity and solar variability) and anthropogenic (greenhouse gas, ozone-aerosols and land use/land cover) individual forcing relative to the full forced simulations. Model results show generalized warming during the MCA in the study area. However, the simulated MCA temperatures are significantly colder than present-day mean values due to the influence of increased atmospheric greenhouse gas concentrations since the beginning of the modern Industrial Era in the ∼1850s. In fact, model runs in which only natural forcings were applied show that, in the absence of greenhouse gas forcing, present-day temperatures in the Antarctic Peninsula and southern Patagonia would be lower than or similar to those during the MCA. The study demonstrates the value of paleoclimate proxy–model comparisons but also highlights the limitations of current available proxy information to perform that integration in the study area.

In this study we present an approach to calibrate a three-dimensional hydrodynamic model of a salt-wedge estuary, the Ararangua Estuary, southern Brazil, based on the Delft3D-FLOW model. The calibration was carried out in four steps to predict the vertical salinity structure along the estuary in an efficient and effective way. Skill assessment was used to evaluate the calibration quality. The model is forced by water-level elevation along the offshore open boundary and river-discharge inflows from the two major tributaries. The hydrodynamic model was calibrated using field observation of water level, currents and longitudinal salinity structure. Calibration was performed adjusting vertical grid resolution, bottom-friction coefficient and background eddy viscosity. The model achieves high skill values at water level and currents variations during a 113-day period (in 2008) covering a wide range of river discharge and tidal forcing. Water surface fluctuations obtained from the model are in good agreement with the field data. Modeled depth-averaged currents reproduce the temporal pattern of observed data. Longitudinal salinity structure is also well reproduced, although the vertical structure is more diffusive than the observations. Results also demonstrate that the model predicts the overall measured phenomena and the effects of the flash-flood event, with the discharge affecting water level, currents and salinity.

This paper investigates cold outbreaks that form offshore density currents within the whole mesoscale over the Western Mediterranean basin. Reflectivity radar and satellite images are used to detect clouds and precipitation that are associated with these density currents in the meso-α, meso-β, and meso-γover the Western Mediterranean basin (WMB). Version 3.3 of the WRF-ARW model is used to describe the formation and evolution of these density currents and to estimate their lifetime as well as horizontal and vertical scales. Based on the observations and simulations, this paper suggests that a new perspective could effectively be adopted regarding the WMB region delineated by the Balearic Islands, the northeastern Iberian Peninsula, and the Gulf of Lion, where inland cold outbreaks develop into density currents that move offshore and can produce precipitation ranging from raincells to rainbands at the whole mesoscale.

Whale falls are important environments contributing to biodiversity, connectivity and evolutionary novelty in deep-sea ecosystem. Notwithstanding, most of this knowledge is based in studies from NE Pacific basin. Interestingly, the only known natural whale fall on the SW Atlantic has faunal composition affinities with carcasses from other deep-ocean basins. In this carcass, annelid worms belonging to Hesionidae are abundant and species-rich, and include some shared species with NE Pacific Ocean. Here we evaluate the diversity of Hesionidae on the SW Atlantic using new information of implanted whale bones and explore whether some species have interbasin distribution or if they represent cryptic species in different basins. We described, using morphological and molecular data, a total of 10 new hesionid species and report of a new lineage Sirsoe ‘BioSuOr,’ not formally described herein. Two hesionids found exclusively in deep-sea chemosynthetic environments, SirsoePleijel (1998) and VrijenhoekiaPleijel et al. (2008), are primarily distinguished from each other by the presence of a median antenna on the former and its absence on the latter. However, our analyses showed that Vrijenhoekia should be synonymized with Sirsoe and for this reason we emended the diagnosis of Sirsoe. We also emphasized the presence of Sirsoe balaenophila comb. nov. and S. sirikos in SW Atlantic whale falls confirming their interbasin distribution. Moreover, COI and 16S rDNA data reveal that S. balaenophila comb. nov. also comprises cryptic species on the SW Atlantic (S. pirapuan sp. nov. and S. ypupiara sp. nov) and perhaps also in the Pacific Ocean (herein named as S. balaenophila lineage-2). The new species, S. maximiano, is shared between whale falls from SW Atlantic and vent sites from Mid-Cayman Spreading Center. Our data adds to the growing literature showing species are shared between deep ocean basins and among cognate deep-sea environments. Zoobank registration publication LSID - urn:lsid:zoobank.org:pub:7E891B1D-DCE4-45C8-83F4-8586D286B327.

[EN] This Thesis is a high resolution micropaleontological study of the IODP Site U1314, recovered during the IODP 306 Expedition, in the Gardar Drift formation (southern Iceland), in the subpolar North Atlantic. The main purpose of this Thesis is the study of climatic variations at different time scales (orbital and suborbital) and the evolution of surface circulation patterns in the North Atlantic through changes in the associations of cocolitophorids that occurred during the interval between 1,050,000 and 400,000 years (MIS 30-11); known as the Middle Pleistocene Transition. The reason for studying the coccolitophorids assemblages’ variations is due to the fact that they conform one of the main components of the phytoplankton in the current oceans. These organisms secrete calcified plaques (cocoliths) that, after sedimentation in the seabed, can be preserved in the fossil record. Coccolithophore abundance and diversity are highly influenced by the environmental conditions that prevailed at time these organisms inhabited the ocean. Hence, the study of coccoliths preserved in the sedimentary record provides useful information to perform paleoenvironmental reconstructions. In this Doctoral Thesis, a record of calcareous nanofossils has been analyzed in the interval from MIS 11 to 30. In addition, statistical and mathematical analyses of the calcareous nanofossils assemblage, especially the spectral analysis and the analysis of delays between different variables (LAG), have been made in order to know the responsetime between two systems (or sites) affected by the same climatic effect. We have also compare our study with site MD03-2699 (southern of site U1314), with the aim of reconstructing how and when the NAC (North Atlantic Current) could vary in the MIS 11-14 interval. The importance of this study, located in the North Atlantic and specifically the subpolar North Atlantic, is related to the sensitivity of the area to climatic and oceanographic changes. The surface oceanographic regime is strongly imprinted by the Subpolar gyre, specifically by the NAC, which feeds the IC (Irminger Current). When the NAC and the IC arrive at high latitudes, they will sink generating deep waters masses. Oceanographic changes at deep waters are important in this area because it is a deepwater formation zone (Labrador Sea and Norwegian Sea-Greenland), which is the motor of the thermohaline circulation and affect the global circulation. The calcareous nanofossils asemblages showed abrupt changes between the warm interval assemblage, where the total abundance of species is greater and dominated by the species associated to the IC and the cold interval assemblage where the total abundance is low and the species associated with waters of the IC abruptly decline. These abrupt changes are due to the latitudinal variation of the NAC waters and the cold waters from farther north, which ultimately determine the position and variation of the IC waters. This variation of the waters throughout the study interval allows us to reconstruct four scenarios of surface water circulation: High advection of the Irminger waters, low advection of the Irminger water, advection of polar water and terminations. The analysis of the cyclicity of the different records elaborated in this Thesis has shown that the associations of nanofossils have been affected by the three orbital parameters: eccentricity, obliquity and precession, which have allowed to observe a progressive increase in the importance of the precession in the climate cycles, which could affect the insolation on the sea surface, which ultimately affected the position of the ocean currents., [ES] El estudio de los eventos climáticos abruptos y de los mecanismos implicados representan uno de los mayores retos a los que se enfrenta la investigación climática hoy en día. La identificación de los mecanismos de retroalimentación entre los sistemas océano- atmósfera-criosfera son de vital importancia para la comprensión de la variabilidad climática presente en registros sedimentarios del fondo oceánico. Entender cómo y por qué ocurrieron los cambios climáticos del pasado nos puede ayudar a predecir futuros escenarios relacionados con cambios climáticos. En esta Tesis se aportan nuevos datos y enfoques sobre los cambios climáticos y oceanográficos que se registraron entre aproximadamente 1,050,000 y 400,000 mil años en las latitudes altas del Atlántico Norte y que se relacionan con el clima y la circulación oceánica global. El Atlántico Norte subpolar está considerado como una de las regiones climáticas más sensibles de la Tierra y es la llave fundamental para la compresión de la de la circulación de retorno (AMOC) en el Atlántico. Las variaciones de los parámetros superficiales influyen en la circulación y en la formación de masas de agua profundas, explicando por qué las variaciones entre periodos glaciares e interglaciares afectan a la formación de agua profunda, a cómo el calor se distribuye en el océano y a la distribución vertical de nutrientes que afectan a las comunidades planctónicas. El intervalo de tiempo estudiado en esta Tesis Doctoral está caracterizado por la asimetría en los ciclos climáticos y contiene la llamada “transición del Pleistoceno medio”, entre los 1.1 y 0.6 Ma, caracterizados por una reorganización climática que se ha registrado en sedimentos marinos y continentales y se caracteriza por cambios a nivel global, entre los cuáles se incluyen cambios en temperatura del mar, nivel del mar y masas de hielo y afectó a la distribución y evolución de la vida en la Tierra, incluyendo a los ancestros de los seres humanos modernos. Durante la primera parte del intervalo de estudio, predominan los ciclos de ~100 ky que habían surgido entre los 950-900 ka mostrando un aumento progresivo en la intensidad de los periodos glaciales, produciéndose grandes acumulaciones de hielo en el hemisferio norte. Sin embargo, no es hasta aproximadamente los 400 ka (durante el periodo llamando “Evento Mid-Brunhes”) cuando los ciclos de ~100 ka adquieren su mayor amplitud, caracterizándose por periodos glaciales muy fríos e interglaciales muy cálidos. Dada la estrecha relación entre hidrosfera y criosfera, esta reconfiguración del volumen de hielo global tuvo gran repercusión en los patrones de circulación oceánica superficial y profunda a nivel global y muy especialmente en la región del Atlántico Norte. Establecer cuáles son los mecanismos de retroalimentación implicados en esta reconfiguración del sistema climático a escala orbital y suborbital representa uno de los grandes retos de la paleoclimatología moderna que se trataran en esta Tesis. El trabajo presentado se basa en el análisis de una secuencia sedimentaria del sondeo marino profundo U1314, perforado en la formación Gardar Drift (sur de Islandia), durante la Expedición 306 del Integrated Ocean Drilling Program (IODP) en el Atlántico Norte subpolar. El material recuperado proporciona un registro de alta resolución del intervalo comprendido entre 1.050.000 y 400.000 años.

[EN] In this work I reconstruct past sea surface water conditions on the SW Iberian Margin by analysing planktonic foraminifer assemblages from IODPSite U1 (37º34.285´N,10º7.562´W;2585mdepth).The data provide a continuous climate record from Marine Isotope Stages (MIS) 21 to 13,extending the existing paleocli recorothIberian Margin back to the ninth climatic cycle (867 ka)., [ES] En esta tesis se reconstruyen las condiciones paleoceanográficas superficiales en el margen occidental ibérico mediante el análisis de las asociaciones de foraminíferos planctónicos de sedimentos procedentes del testigo IODP-U1385 (37º34.285´N, 10º7.562´W; 2585 m de profundidad). Los datos proporcionan un registro climático continuo y de alta resolución para los estadios isotópicos marinos (MIS) 21 a 11, ampliando el registro existente del margen ibérico hasta el noveno ciclo climático (867 ka).

Rio Grande Rise (RGR) is a broad elevation in the South Atlantic Ocean consisting of western and eastern parts, that in total measures about 874 km east-west by about 480 km north-south. There is a scarcity of available information to the scientific community and to address this, the Marine E-tech project has taken a holistic and interdisciplinary scientific approach to understand the oceanographic and geological environment of the rise. Here we present geophysical, geological, biological and physical oceanography dataset spanning a depth range from 640 to 2060 m acquired during a multidisciplinary scientific cruise to RGR in 2018.

In this work, we describe a mechanism by which South Atlantic Central Water is upwelled to shelf-break levels, subsequently mixed with the Tropical Water in the upper portion of the water column, and advected oceanward as a plume, reaching a distance of more than 250 km from the shelf break. This process is due to the coupling of two quasi-stationary Brazil Current (BC) mesoscale features: the anticyclonic Abrolhos Eddy (AE) and the cyclonic Vitoria Eddy (VE), located north and south of the Vitoria-Trindade Ridge (~20.5oS) respectively. As they pair around a topographic feature known as Besnard Bank, they form an eddy dipole with a ~2 Sv velocity-intensified BC channeled between the two eddies. During an AE-VE dipole event the BC acquires a cross-isobath direction, which causes horizontal divergence near the shelf break. Therefore, in this scenario, the BC turns into a jet that ejects a nutrient-rich central water mix toward the deep ocean. Considering that we can track the nutrient-rich tongue of water by its higher chlorophyll-a signature, it may be relevant in the understanding of the pelagial biota ecology of the surroundings.

It is well known that some factors could effectively control the hydrodynamics of Brazil’s largest coastal lagoon (Patos Lagoon coastal system); however the knowledge about the effects of such factors on its water quality indicators (WQI) is scarce. Therefore, our aim is to assess the relative importance of the main factors that control the hydrodynamics of the Lagoon (wind and river discharges) on spatial and temporal variations of water quality indicators, being these indicators the suspended solids, dissolved oxygen, total inorganic nitrogen and chlorophyll-a. With this knowledge we can indicate areas with greater or lesser susceptibility to water quality deterioration. We applied the MOHID 2D numerical model to assess the combined effect of winds and river discharge on WQI throughout the entire lagoon system. Our results indicate that winds combined with river discharge affect the spatial–temporal variation of the WQI, with the largest variations occurring under high river discharge and southwest winds, especially in the estuarine area. Regardless of the magnitude of the incoming discharge, the spatial variations are similar for the same winds. Sub-areas with homogeneous conditions are observed independently of the hydrodynamic forcings.

The Caravelas estuary is located in a zone of the Brazilian coast (Southern Bahia State) which has been submitted to different kinds of land uses during the last 50 years. This zone has an important ecological role, due to its mangroves and its location next to Abrolhos coral reef, the most important in the Southern Atlantic Ocean. 210Pb and 137Cs dating methods, accompanied by a sedimentological study, were applied to sediment cores in order to establish sedimentation rates and identify historical trends of land use and erosive processes. Sedimentation rates were established according to the “Constant Rate of Supply” (CRS) 210Pb dating model, which was preferred rather than the “Constant Initial Concentration” (CIC) model. Corrected sedimentation rates obtained from 210Pb dating were corroborated through a second independent radionuclide tracer such as 137Cs. The sedimentation rates obtained according to the CRS model for the cores were 1.07 ± 0.13 cm yr –1 for T#2 (inner sector), 0.65 ± 0.06 cm yr –1 for T#5 and 0.85 ± 0.09 cm yr –1 for T#8 (outer sector). The difference in sedimentation rates among the sampling sites could be due to hydrodynamic processes and could be related to the tendency of increase of erosive processes, conditioned by the changes in the landscape and land use to, which this region has been submitted.

OCEANS 2017, 19-22 June 2017, Aberdeen, Most Autonomous Underwater Vehicles (AUVs) mount an Acoustic Doppler Current Profilers (ADCP). Data from this sensor are rarely used in scientific studies due to the complexity of its processing and the lack of validation. Aside of that, AUV operators lack a set of guidelines regarding the optimal navigation modes and AUV-borne ADCP configurations to obtain the most accurate data possible. This study compares 12.6 hours of AUV-borne ADCP currents measurements, taken in different AUV navigation modes and ADCP configurations, to those of a moored AWAC. Results show RMS errors of 5 cm/s for U (East) and V (North) measures and of 2 cm/s for vertical currents measures for most of the navigation modes. Cell size is found to be the most influential parameter in data accuracy and yo-yo type of surveys are proved to be as accurate as constant depth ones

International audience; The Exclusive Economic Zone of Chile defined by Easter Island and Salas y Gómez Island is in the South Pacific Subtropical Gyre (SPSG), putting it at the center of the most oligotrophic and biomass poor waters in the world. Only 10 biological oceanographic expeditions have entered this zone in 105 years (1905-2010). We review key aspects of the plankton ecosystem and biogeochemical function relevant for the understanding of and conservation planning for marine environments. Plankton production is limited by lack of dissolved inorganic fixed nitrogen, not phosphorous. Higher organic nitrogen levels might be biologically unavailable. Short-term experiments suggested iron is not limiting, yet iron still likely limits nitrogen fixation, and thus production, at longer time scales, as the presence of nitrogen-fixers is exceptionally low compared to other ocean gyres. Plankton function is dominated by the smallest unicellular organisms, picoplankton (

The growing scientific and societal concerns about the effects of underwater sound on marine ecosystems have been recently recognised through the introduction of several international initiatives, like the International Quiet Ocean Experiment, aimed at measuring the environmental impact of ocean noise on large spatial and temporal scales. From a regulatory perspective, the European Marine Strategy Framework Directive includes noise (and other forms of energy) as one of eleven descriptors of good environmental status of Europe's seas. The directive requires member states to monitor trends in annually averaged sound. The Laboratory of Applied Bioacoustics has developed a software package that measures sound levels and monitors acoustic sources in real-time; this software was used for the LIDO project (www.listentothedeep.com), which originated from the European Seafloor Observatory Network of Excellence (ESONET-NoE; www.esonet-noe.org). The system is currently operating worldwide from several wired and radio-linked observatories. The CTBTO (Preparatory Commission for the Comprehensive Nuclear-Test-Ban Treaty Organization) has made available years of data from hydroacoustic stations to look for ambient sound trends and to detect cetacean presence. Here, we present the analysis of four CTBTO platforms (located in the Pacific, Atlantic and Indian oceans), covering 42. months of data, intended to detect annual and monthly changes or trends in the ambient sound levels. © 2013 Elsevier B.V.

RESUMO A investigação de processos inerentes a um sistema estuarino permite inferir de forma mais precisa a complexa dinâmica de constituintes presentes em suas águas, de modo a otimizar estratégias de ação em planos de gestão e projetos ambientais em regiões costeiras. Este trabalho apresenta um estudo da hidrodinâmica do Sistema Estuarino de Santos (Estado de São Paulo), com enfoque em aspectos relacionados ao transporte de constituintes presentes em suas águas de origem continental. Por meio do SisBaHiA (Sistema Base de Hidrodinâmica Ambiental) foi implementado um modelo hidrodinâmico computacional para a reprodução dos padrões de circulação do sistema. A partir de simulações com o Modelo de Transporte Lagrangeano, foram representadas as descargas dos afluentes mais expressivos: Rio Boturoca, Rio Cubatão, Rio Quilombo e Rio Itapanhaú. Os resultados foram analisados probabilisticamente em função do tempo de vida das águas que adentram o sistema e de suas porcentagens de ocorrência, numa determinada posição ao longo do período de simulação. Esses resultados permitiram analisar as trajetórias das águas continentais afluentes, na forma de mapas de isolinhas de porcentagem de ocorrência, separados por tempo de vida limite. Os mapas indicaram que as águas do Rio Cubatão alcançam a Baía de Santos preferencialmente pela embocadura do Estuário de São Vicente, diferentemente do Rio Quilombo, cujas águas seguem preferencialmente pelo Canal do Porto. As águas do Rio Cubatão permaneceram na maior parte do tempo aprisionadas nas regiões de mangue. Considerando 3 dias de tempo de vida, apenas durante 1% do período simulado, estas alcançaram os canais principais. ABSTRACT In order to optimize action strategies for environmental management plans and environmental projects in coastal areas, the investigation of processes related to an estuarine system contributes to a better inference of the complex dynamics of constituents present in its water. This paper reports a hydrodynamic study of the Santos Estuarine System (São Paulo State, Brazil) focused on aspects related to the transport of constituents from inland water discharges. A computational model was implemented using SisBaHiA (Base System for Environmental Hydrodynamics) in order to reproduce the hydrodynamic patterns of the system. Based on the Lagrangian Transport Model the most significant tributary river discharges were represented: Boturoca River, Cubatão River, Quilombo River and Itapanhaú River. Results were probabilistically analyzed based on the lifetime of tributary discharges flowing into the estuarine system and their position during the simulation period. Such simulation results were presented on contour maps of occurrence percentage separated by lifetime limits, supporting a trajectory analysis of the inland water discharges. Map results indicated that water from Cubatão River reaches the Santos Bay preferably through the mouth of the São Vicente Estuary and water from Quilombo River preferably flows through the Port of Santos Channel instead. Water from Cubatão River remained in a mangrove area during most of the simulation period. Considering 3 days of lifetime limit only 1% reached the main channels.

The Bertioga Channel (SE Brazilian coast) is part of the Santos Estuarine Complex, situated at the Baixada Santista. The Baixada Santista...

Organochlorines (OCs), such as pesticides and polychlorinated biphenyls (PCBs), are persistent, toxic and widely distributed through atmospheric transport and ocean currents. Few studies have been conducted on OCs in sea turtles, especially on the coast of Brazil. Chelonia mydas is the largest hard-shell sea turtle and is found tropical and subtropical regions in all oceans. The aim of the present study was to determine the occurrence of OCs in the green sea turtle (C. mydas). Fat, liver, kidney and muscle samples were collected from 27 juveniles found on the beach of the city of Ubatuba on the northern coast of the state of Sao Paulo, Brazil. OCs were extracted with organic solvents and the extract was purified with concentrated acid. Gas chromatography-mass spectrometry and electron capture detection were used for the identification and quantification of PCBs and pesticides, respectively. No organochlorine pesticides were detected in any of the samples. Concentrations of total PCBs in wet weight were

Coastal lagoons across the globe are increasingly experiencing undesired and sudden changes caused by human disturbances. Nevertheless, little is known about how long-term natural dynamics and anthropogenic impacts interact to drive the systems to their current state. This study discriminated natural- and human-induced changes in a shallow coastal lagoon near Punta del Este, Uruguay, using a multidisciplinary approach. The genesis of the water body resulted from a Middle Holocene marine transgression circa 6000 yr cal BP. From this time to about 4400 yr cal BP, a comprehensive set of proxies revealed a highly variable scenario, with alternating lagoon states linked to climatic variability. A Late Holocene hiatus was also identified in the sediment profile, linked to the barrier and inlet formation that caused a predominance of erosion over net deposition. Results showed that anthropogenic disturbances modified the landscape substantially and shifted the entire watershed to a previously unknown and undesired state. A freeway constructed in 1955 AD subsequently closed the lagoon's natural inlet and transformed the coastal water body into an artificial reservoir. After such significant human impact, the lagoon experienced a sharp decrease in water surface area along with an intensification of the siltation/eutrophication processes, as inferred from multiproxy data. Findings of this study are useful to identify early signals of human disturbances in pristine or less impacted coastal systems to assist mitigation measures and/or restoration actions. Fil: Inda, Hugo. Universidad de la República; Uruguay Fil: Garcia Rodriguez, Felipe. Universidad de la República; Uruguay Fil: del Puerto, Laura. Universidad de la República; Uruguay Fil: Stutz, Silvina Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencia Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentina Fil: Lopes Figueira, Rubens Cesar. Universidade de Sao Paulo; Brasil Fil: de Lima Ferreira, Paulo Alves. Universidade de Sao Paulo; Brasil Fil: Mazzeo, Néstor. Universidad de la República; Uruguay

The Antarctic continent is considered a low-impact environment; however, there is a tendency to increase the contaminants' levels due to human activities in the research stations. In this study, As, Cd, Cr, Cu, Hg, Ni, Pb and Zn levels in sediment and biota were determined in the environmental samples from Admiralty Bay (King George Island, Antarctica) collected in 2003. The results demonstrated high concentrations of Cu and Zn in the sediments. There was bioaccumulation of As in the biota from Admiralty Bay and bioaccumulation of Zn specifically in the biota from Martel Inlet. In addition, the results were useful in order to understand the heavy metal levels for the pre-accident condition of Comandante Ferraz Antarctic Station, where an accident occurred in 2012, and also for the comparison with current conditions within the monitoring work developed by INCT-APA (National Institute of Science and Technology for Environmental Research Antarctic).

A new species of Characidium is described based on specimens obtained from the highland streams of the Serra do Mar, Atlantic Forest Biome, in Paraná State, Southern Brazil. The new species is possibly a member member of the C. lauroi group, which is diagnosed by having the isthmus unscaled, bars poorly marked, and spots on sides of body, and is composed by four additional species: C. japuhybense ; C. lauroi ; C. oiticicai ; and C. schubarti . The new species differs from its congeners with naked isthmus, except C. helmeri , by having 15-18 principal caudal-fin rays; and 10-12 pectoral-fin rays; and from C. helmeri , by having a slender body, tip of pectoral fin not reaching origin of pelvic fin, tip of pelvic fin not reaching beyond anus, supraorbital present and well developed, and by lacking vertically elongated dashes on sides of body. The new species is known from tributaries of the rio Jordão, in the rio Iguaçu Basin, and rio Taquari, a tributary of the rio Ribeira de Iguape coastal drainage. RESUMO Uma nova espécie de Characidium é descrita com base em exemplares obtidos de riachos de altitude da Serra do Mar, no bioma Mata Atlântica, do Estado do Paraná, Sul do Brasil. A nova espécie é possivelmente um membro do grupo C. lauroi , que pode ser diagnosticado por possuir o istmo sem escamas, barras pouco marcadas e pontos nos lados do corpo, e é composto por quatro espécies adicionais: C. japuhybense ; C. lauroi ; C. oiticicai ; e C. schubarti . A nova espécie difere de seus congêneres com istmo nú, exceto C. helmeri , por possuir 15-18 raios principais na nadadeira caudal, e 10-12 raios na nadadeira peitoral; e de C. helmeri , por possuir o corpo mais alongado, pela ponta da nadadeira peitoral não alcançar a nadadeira pélvica, pela ponta da nadadeira pélvica não alcançar o ânus, pelo supraorbital presente e bem desenvolvido, e pela ausência de manchas verticalmente alongadas na porção ventral do corpo. A nova espécie é conhecida de duas drenagens, nos tributários do rio Jordão, na bacia do rio Iguaçu, e no rio Taquari, um tributário da bacia costeira do rio Ribeira de Iguape.

This paper analyzes a simplified image reconstruction method that exclusively takes into account the dominant antenna pattern terms to model image inversion artifacts and mitigate SMOS polarimetric spatial bias over the Ocean. This simplified method, that reduces computation time at the cost of small radiometric performance degradation, is useful to the L1 teams to process a large amount of data when full radiometric accuracy is not required (e.g. stability assessments).

Paranagua Bay is one of the largest estuarine systems on the Southern Brazilian coast. The only recorded cholera outbreak in this region since the early 20th century occurred in 1999 and resulted in 467 cases and at least three reported deaths in a population of approx. 150 000 people. This short communication reports historical, unpublished data related to that outbreak. Water, zooplankton and bivalve samples were collected and evaluated using direct fluorescence assay to determine whether Vibrio cholerae serogroups O1 and O139 were present in the estuarine system at that time. Most of the water (83%) and zooplankton samples (75%) were positive for V. cholerae O1, while V. cholerae O139 was not detected. Shellfish (Mytella sp.) were also positive for V. cholerae O1. These results indicate that the estuary, including biological vectors such as copepods and bivalves, comprise an important reservoir of V. cholerae O1 and a probable waterborne pathway for the disease, in addition to contamination with untreated sewage. Significance and Impact of the Study Despite most of the cholera cases that occurred in Brazil during the 7th pandemic were located in the northern areas of the country, a significant outbreak in Paranagua, an estuary in the south coast, resulted in at least three deaths in 1999. We report here the detection of Vibrio cholerae O1 in water, zooplankton and bivalve samples during the outbreak, using direct fluorescence assay as an alternative method for the traditional plate culture employed at the time by the Brazilian Sanitary Agency. Results demonstrate that aquatic natural reservoirs comprise a potential route of transmission of cholera, in addition to untreated sewage and routine monitoring is recommended.

A novel Amazonian reef biome was discovered, encompassing large rhodolith and sponge beds under low light, low oxygen, and high POC., Large rivers create major gaps in reef distribution along tropical shelves. The Amazon River represents 20% of the global riverine discharge to the ocean, generating up to a 1.3 × 106–km2 plume, and extensive muddy bottoms in the equatorial margin of South America. As a result, a wide area of the tropical North Atlantic is heavily affected in terms of salinity, pH, light penetration, and sedimentation. Such unfavorable conditions were thought to imprint a major gap in Western Atlantic reefs. We present an extensive carbonate system off the Amazon mouth, underneath the river plume. Significant carbonate sedimentation occurred during lowstand sea level, and still occurs in the outer shelf, resulting in complex hard-bottom topography. A permanent near-bottom wedge of ocean water, together with the seasonal nature of the plume’s eastward retroflection, conditions the existence of this extensive (~9500 km2) hard-bottom mosaic. The Amazon reefs transition from accretive to erosional structures and encompass extensive rhodolith beds. Carbonate structures function as a connectivity corridor for wide depth–ranging reef-associated species, being heavily colonized by large sponges and other structure-forming filter feeders that dwell under low light and high levels of particulates. The oxycline between the plume and subplume is associated with chemoautotrophic and anaerobic microbial metabolisms. The system described here provides several insights about the responses of tropical reefs to suboptimal and marginal reef-building conditions, which are accelerating worldwide due to global changes.

Estuarine processes are directly related to the interaction of its forcing conditions with the local morphology. In this study we assess the implications of the opening of a new inlet on the hydrodynamics and suspended sediment concentration (SSC). A set of physical parameters have been measured in the Itanhém river estuary, a small, shallow and mangrove fringed tropical estuary in Northeastern Brazil. Field surveys have been conducted in August 2007 and January 2008, separated by an important morphological change. Our observations show that even shortening the lower estuary channel in 2 km, the inlet opening did not imply in changes in the estuarine circulation. However, SSC increased after the inlet opening. General estuarine circulation showed synodical modulation of tidal asymmetry and residual suspended sediment transport. The estuary showed flood dominance at spring tide and ebb dominance at neap tide. Although not directly changing the estuarine hydrodynamics, the morphological change resulted in an important increase in SSC. This increase might be related to a facilitated import of inner shelf sediment through a shorter channel, having important implications for the estuarine sedimentation processes.