Brazilian Journal of Oceanography最新文献

{"title":"Genesis of submerged sandstones in Paraná State continental shelf, Southern Brazil, based on cementation patterns, ages and stable isotopes","authors":"B. I. Simioni, R. J. Angulo, F. Veiga, Luiz Henrique Sielski de Oliveira, M. C. Souza","doi":"10.1590/S1679-87592018019306603","DOIUrl":"https://doi.org/10.1590/S1679-87592018019306603","url":null,"abstract":"Beachrocks are a common feature along the Brazilian coast and although their occurrence in intertidal zones is concentrated in tropical regions, similar formations have been described submerged on the continental shelf in subtropical regions. In the state of Paraná, submerged sandstones are present on the continental shelf and their formation could be associated with the cementation of beach sediments. This would provide an excellent indicator of the stabilization of the coastline during lower sea-level periods. In this study, samples were identified and collected in Paraná State, Southern Brazil, at depths between 18 and 33 meters in the continental shelf and at 6 meters depth in the Paranaguá Bay inlet. As in situ observations proved problematic, analysis relied mainly on their petrography, mineralogy, ages and isotopic values (δ13C and δ18O). Whole rock dating demonstrated that the oldest acquired sample was formed 28109-26406 cal. years BP, being exposed to atmospheric conditions during the Last Glacial Maximum. This exposure is reflected in its cements, composed uniquely of microcrystalline and spar calcite, and on its δ18O/δ13C values, which indicates formation on a fresh water environment. Contrarily to most carbonate cemented products described along Brazilian coastline, δ13C values ranged between -26.36 and -51.07‰ on all other samples, interpreted as a result of cement precipitation prompted by methane, either: in a paleo-estuarine/ paleo-lagunar to transgressive environment buried under a pile of coarser material or; after transgression and drowning of organic-rich sediments by coarser sediments, and due to upward migration of methane on the sedimentary column. Both processes would result in cements identified on these samples, apart from the one collected closer to shore which indicates some freshwater influence. Two of the samples separated by 15km distance perpendicularly to the actual coastline and 11m depth difference yielded max and minimum ages of 7913 and 7452 cal. years BP. Such a short time span between these samples could be either the result of their formation on a linked environment or older carbon signature from drowned environments being present on younger cements. AbstrAct Bruno Ivan Simioni1* , Rodolfo José Angulo1, Fernando Alvim Veiga1, Luiz Henrique Sielski Oliveira1, Maria Cristina de Souza1","PeriodicalId":55325,"journal":{"name":"Brazilian Journal of Oceanography","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1590/S1679-87592018019306603","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46993917","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"New records of association between Brachyscelus cf. rapacoides (Arthropoda: Amphipoda) and medusae (Cnidaria: Scyphozoa and Hydrozoa) from São Sebastião Channel, southeast Brazil","authors":"F. A. P. Tapia, R. Gasca, G. Genzano, A. Schiariti, A. Morandini","doi":"10.1590/S1679-87592018017806603","DOIUrl":"https://doi.org/10.1590/S1679-87592018017806603","url":null,"abstract":"1 Instituto de Investigaciones Marinas y Costeras (IIMyC), Universidad Nacional de Mar del Plata (UNMdP) (Rodríguez Peña n°. 4046, Mar del Plata, Buenos Aires, Argentina) 2 Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) (Mar del Plata, Buenos Aires, Argentina) 3 El Colegio de la Frontera Sur (ECOSUR) (Av. del Centenario Km. 5.5, Chetumal, Quintana Roo, México. C.P. 77014) 4 Instituto Nacional de Investigación y Desarrollo Pesquero (INIDEP) (Paseo Victoria Ocampo no 1, Escollera Norte, Mar del Plata, Buenos Aires, Argentina) 5 Departamento de Zoologia, Instituto de Biociências, Universidade de São Paulo (Rua do Matão, trav. 14, no 321, Cidade Universitária, São Paulo, Brazil) 6 Centro de Biologia Marinha, Universidade de São Paulo (Rod. Manoel Hypólito do Rego, km 131.5, São Sebastião, Brazil)","PeriodicalId":55325,"journal":{"name":"Brazilian Journal of Oceanography","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42673513","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Diet and reproductive aspects of the endangered butterfly ray Gymnura altavela raising the discussion of a possible nursery area in a highly impacted environment","authors":"F. A. Silva, M. Vianna","doi":"10.1590/S1679-8759201801906603","DOIUrl":"https://doi.org/10.1590/S1679-8759201801906603","url":null,"abstract":"","PeriodicalId":55325,"journal":{"name":"Brazilian Journal of Oceanography","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43866121","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Structure of microphytoplankton community and environmental variables in a macrotidal estuarine complex, São Marcos Bay, Maranhão - Brazil","authors":"L. F. Cavalcanti, A. C. Azevedo-Cutrim, A. L. Oliveira, J. A. Furtado, B. O. Araújo, A. K. Sá, F. S. Ferreira, Nágela Gardênia Rodrigues Santos, F. Dias, M. Cutrim","doi":"10.1590/S1679-87592018021906603","DOIUrl":"https://doi.org/10.1590/S1679-87592018021906603","url":null,"abstract":"São Marcos Bay is an estuarine complex with semidiurnal tides that can reach more than 7 m during equinoctial spring tides. It is situated in the second largest Brazilian coastline and is subjected to continuous human activities holding an important port complex of Latin America. In order to contribute to the knowledge about the structure of the phytoplankton in a macrotidal systems, this study aims to evaluate the phytoplankton community and its relationship with environmental conditions in the São Marcos Bay. Five surveys in 2010 and 2011 were carried out on four sampling points during the rainy and dry seasons. Samples were taken during the flood and ebb phases at neap tides. Hydrological parameters were correlated with biological data (phytoplankton composition, abundance and biomass) using statistical analysis. The phytoplankton biomass (chlorophyll a) characterized the bay as quite productive (10.43±7.62 mg m-3) with the nanophytoplankton as the dominant fraction. Seasonal variation was observed in phytoplankton abundance with higher values (34,262±18,422 cells L-1) in the rainy season. Diatoms were the most important phytoplankton group, pointing out Nitzschia sp., Diploneis weissflogii and Synedra sp. as the dominant species. This study revealed that the composition of phytoplankton community was mainly influenced by the local dynamics, governed by macrotides, and precipitation regime that mostly contributed to the seasonal fluctuations of the environmental conditions, such as salinity, dissolved oxygen, and nutrients. AbstrAct Lisana Furtado Cavalcanti1, Andrea Christina Gomes Azevedo-Cutrim2, Amanda Lorena Lima Oliveira1, Jordana Adorno Furtado1, Bethânia de Oliveira Araújo1, Ana Karoline Duarte-dosSantos Sá1, Francinara Santos Ferreira1, Nágela Gardênia Rodrigues Santos1, Francisco José Silva Dias1, Marco Valério Jansen Cutrim1*","PeriodicalId":55325,"journal":{"name":"Brazilian Journal of Oceanography","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1590/S1679-87592018021906603","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67425150","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tidal and subtidal oscillations in a shallow water system in southern Brazil","authors":"M. M. Andrade, E. Toldo, J. C. Nunes","doi":"10.1590/S1679-87592018017406603","DOIUrl":"https://doi.org/10.1590/S1679-87592018017406603","url":null,"abstract":"Sea level oscillations in time scales between hours and days have a great vertical amplitude regarding the low lying coastal gradient of the beaches in the Rio Grande do Sul coast. However, the mechanism of oscillations is poorly understood since the scarcity of observational data makes it impossible to determine the forces that control sea level oscillations. Therefore, hourly sea level and wind time series with a time period of 650 days were examined. It has been found that the mean tidal and subtidal amplitudes were very similar to each other and that a considerable portion of the energy from sea level oscillations was due to astronomical forces. A new perspective was introduced when high and low frequencies were compared, leading to the comprehension that astronomical tides should be considered in coastal studies in southern Brazil. The sea level time series analyzed in this study showed that the maximum amplitude of the high spring tide was 0.53m, and that the subtidal rise caused by the wind reached up to 0.66m. In general, when large tidal and subtidal amplitudes are added, it can generate extreme events of sea level rise on the coast, which constitute a direct threat to coastal communities and habitats. AbstrAct Mauro Michelena Andrade1* , Elírio Ernestino Toldo2, José Carlos Rodrigues Nunes2","PeriodicalId":55325,"journal":{"name":"Brazilian Journal of Oceanography","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1590/S1679-87592018017406603","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42301094","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Prokaryotic picoplankton distribution within the oxygen minimum zone of the central Mexican Pacific across environmental gradients","authors":"Zuleima Santana-Vega, D. Hernández-Becerril, Alejandro Morales-Blake, F. Varona-Cordero, M. Merino-Ibarra","doi":"10.1590/S1679-87592018004806602","DOIUrl":"https://doi.org/10.1590/S1679-87592018004806602","url":null,"abstract":"Abstract Marine picophytoplankton has become an important issue to understand the global ecology of phototrophic forms, due to its wide distribution and contribution to biomass and productivity. We studied the abundance, distribution and signature pigments of the prokaryote picophytoplankters Prochlorococcus and Synechococcus during an oceanographic cruise (26 April to 7 May, 2011) in the central Mexican Pacific, a relatively poorly-known oxygen minimum zone (OMZ), and the effect of three environmental gradients. Prochlorococcus and Synechococcus abundances were comparable with those found in other tropical areas (0.17 to 30.37 X 104 cells mL-1, and 0.9 to 30.97 X 104 cells mL-1, respectively). Prochlorococcus abundances reached highest numbers in deeper waters, often coinciding with the second deep in situ fluorescence (and chlorophyll α) maxima, at oceanic stations, below the nitratecline, whereas Synechococcus abundances were higher at subsurface waters and its concentration maxima usually coincided with the subsurface in situ fluorescence maxima, with slightly higher abundances in coastal stations. Statistical analyses support significantly these results. Distribution of divinyl-chlorophyll α was erratic along the water column and occasionally coincided with the deep in situ fluorescence maxima, whereas the distribution of zeaxanthin usually followed that of chlorophyll α and the abundances of Synechococcus, and peaked together. These results are similar to those previously found in the study area and in more temperate zones, and also to the general trend in OMZ, but confirm that the second deep chlorophyll α maxima are attributed to high Prochlorococcus densities. We additionally found the abundance and distribution of Prochlorococcus and Synechococcus strongly driven by the environmental gradients observed.","PeriodicalId":55325,"journal":{"name":"Brazilian Journal of Oceanography","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1590/S1679-87592018004806602","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46809153","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Citogenotoxic response of juvenile cobia Rachycentron canadum (Linnaeus, 1766) reared in two different systems","authors":"M. T. Botelho, M. J. A. C. R. Passos, F. M. Hasue, D. Lemos, E. Rodrigues, F. Yasumaru, N. Phan, V. Gomes","doi":"10.1590/S1679-87592018005406602","DOIUrl":"https://doi.org/10.1590/S1679-87592018005406602","url":null,"abstract":"Abstract Aquaculture production is continuously growing worldwide, and marine fish farming in Brazil is still in its infancy. Intensive farming conditions may cause physiological stress to the cultured organism, which can be evaluated by citogenotoxic biomarkers. The aim of this study was to assess the genotoxic effect of the rearing conditions in red blood cells of juvenile cobia Rachycentron canadum by using comet assay and micronucleus and other nuclear abnormalities assay. Juvenile cobia were reared for 13 weeks in indoor tank with open water circulation and in near shore cage. The comet assay and the nuclear abnormalities assay detected higher DNA damage and higher nuclear abnormalities frequency in erythrocytes of fish reared in the indoor tank. Results showed that two methods are complementary. Additionally, cobia were injected with ß-naphthoflavone (BNF) at concentrations of 2mgkg-1 and 10mgkg-1 in laboratory controlled conditions, and maintained for 7 days in separate tanks to better understand the response mechanisms of this species to a toxic substance. The comet assay did not detect any significant differences between BNF injected and control fish, whereas nuclear abnormalities assay showed significant differences between BNF injected and the control groups. The damages identified by the comet assay are repairable breaks in the DNA strands, whereas nuclear abnormalities may be permanent. Possibly the period of maintenance after injection was enough to clean BNF from the organisms and to repair the breaks in the DNA strands. As cobia seems to respond very well to genotoxic elements, comet assay and nuclear abnormalities assay would be useful tools to monitor farming conditions.","PeriodicalId":55325,"journal":{"name":"Brazilian Journal of Oceanography","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1590/S1679-87592018005406602","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41906023","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Morphodynamics of a wave dominated embayed beach on an irregular rocky coastline","authors":"Mario Luiz Mascagni, E. Siegle, M. G. Tessler, S. C. Y. Goya","doi":"10.1590/S1679-87592018005006602","DOIUrl":"https://doi.org/10.1590/S1679-87592018005006602","url":null,"abstract":"Abstract Wave-dominated embayed beaches on irregular rocky coastlines are highly appreciated for their landscapes and tourism potential. Yet our understanding about the interaction of the oceanographic processes with the geological inheritance in this type of beaches still needs further investigation to better understand their natural balance. In this study, we apply the classical approach of morphodynamics to describe for the first time the variations in the Boiçucanga beach morphology, an embayed beach located in São Sebastião City on an irregular rocky coastline that is well known for its beautiful beaches embedded in the valleys of Serra do Mar. Field surveys were performed over 15 months, between April 2008 and September 2009, seeking to evaluate the interactions among the morphology, sediments and hydrodynamic characteristics at Boiçucanga. All data generated during the field surveys have supported the application of the following morphodynamic models: Classification of morphological beach stages [O]; Number of nearshore sandbars [B*]; Relative tide range [RTR]; Beach exposure on embayed coasts [Ro/a and ß]; and Embayment beach scaling parameter [d] to determine the geomorphological behavior of the beach on monthly and annual time scales. From these models, Boiçucanga is classified as a deep embayed beach exposed to high-energy waves, with a predominant reflective profile, which favors the development of beach cusps and topographically controlled rip currents. The combined results of the field observations and applied models allowed us to better understand the role of geological heritage in the two morphodynamic signatures found at the same beach arch. For future studies, we will focus on numerical models to increase the understanding of the hydrodynamic processes that govern the sediment transport in Boiçucanga.","PeriodicalId":55325,"journal":{"name":"Brazilian Journal of Oceanography","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1590/S1679-87592018005006602","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46020936","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation of persistent coherent structures along the Southern Brazilian Shelf","authors":"M. Hodapp, Eduardo de Paula Kirinus, W. Marques, P. Oleinik, O. O. Möller","doi":"10.1590/S1679-87592018005906602","DOIUrl":"https://doi.org/10.1590/S1679-87592018005906602","url":null,"abstract":"Abstract The freshwater-influenced region of the Patos Lagoon discharge to the Southern Brazilian Shelf (SBS) is a region of complex fluid dynamics. Seasoning and synoptic variable winds and coastal current conditions create an alternating flow pattern. The aim of this paper was to investigate the occurrence of persistent coherent structures in this environment. A numerical approach was chosen to describe the main hydrodynamic features of the region during a climatological year. The open-source finite-element code Telemac-Mascaret was applied to the three-dimensional domain. In addition the two-equation k-epsilon model described the turbulence mechanisms. The presence of persistent high-turbulent structures was identified within the study area. These occur as a strong curvilinear disturbance characterized by higher turbulent production and dissipation rates, which increase local mixture. As a result, upward circulation flow was observed, which may be due to irregularities in bottom topography associated with wind-induced stress forces. These results increase the information about the circulation structures of the study area by means of numerical modelling analysis.","PeriodicalId":55325,"journal":{"name":"Brazilian Journal of Oceanography","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1590/S1679-87592018005906602","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41822569","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modelling the effects of sea-level rise and sediment budget in coastal retreat at Hermenegildo Beach, Southern Brazil","authors":"S. A. Figueiredo, L. Calliari, A. Machado","doi":"10.1590/S1679-87592018009806602","DOIUrl":"https://doi.org/10.1590/S1679-87592018009806602","url":null,"abstract":"Abstract Climate change effects such as accelerated sea-level rise, wave climate alteration and disturbances on sediment-budgets are anticipated to lead to a range of adverse impacts in coastal regions around the world. A rise in sea-level is expected to cause shoreline recession, and a sediment deficit can have a similar effect. Since large uncertainties exist in relation to sea-level rise rates and sediment budgets, it is relevant to determine how sensitive the coast is to each of these disturbances. In this context, this paper provides a quantitative evaluation of each of these parameters in terms of modeled coastal recession through risk-based assessments using an aggregated coastal model, the DRanSTM (Dilating Random Shoreface Translation Model). In each separate computer simulation, a sediment budget and a sea-level scenario were set for an erosional coastal stretch: Hermenegildo Beach, Rio Grande do Sul state in southern Brazil. Effects of changes in wave climate were not directly considered in this study. However, indirect measures of such changes should be reflected on coastal sediment budgets. Simulation results demonstrate that under present-day sea-level rise rates, sediment deficit exerts control over coastal recession. Conversely, under the higher forecasted sea-level rise for the year 2100, mean shoreline recession will be dictated by sea-level rise, considering historical sediment deficit will be sustained.","PeriodicalId":55325,"journal":{"name":"Brazilian Journal of Oceanography","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1590/S1679-87592018009806602","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45662325","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}