Remarks on the morphology and distribution of some rare centric diatoms in southern Brazilian continental shelf and slope waters

This paper provides information on the morphology and occurrence of extant diatoms of the family Asterolampraceae and Azpeitia species of the southernmost Brazilian continental shelf and slope waters in the Southwestern Atlantic Ocean (28 - 34°S), under the influence of Tropical, Subtropical, Subantarctic Waters, terrestrial discharges from La Plata River and Lagoa dos Patos lagoon. Plankton was sampled (20 µm net; vertical hauls) at the same 27 stations in winter 2005 and summer 2007. Among Asterolampraceae, Asteromphalus flabellatus was the most frequent species (57% of samples) observed mainly in winter samples (92%) in Subtropical Shelf Water but also under the influence of La Plata River plume (salinity <35). Lower frequencies were observed for Asterolampra marylandica, Asteromphalus elegans, Asteromphalus heptactis and Spatangidium arachne. Four species of Azpeitia were observed: A. barronii and A. neocrenulata for the first time in the South Atlantic Ocean while A. africana and A. nodulifer had already been registered in equatorial and southern areas of Brazil. All Azpeitia species were rare (19%) in offshore samples (100-200 m depth. Remarks on the morphology based on light and scanning electron microcopy observations are provided along with their distribution in the study area.

Isotope and fatty acid trends along continental shelf depth gradients: Inshore versus offshore hydrological influences on benthic trophic functioning

Anthropogenic activities and land-based inputs into the sea may influence the trophic structure and functioning of coastal and continental shelf ecosystems, despite the numerous opportunities and services the latter offer to humans and wildlife. In addition, hydrological structures and physical dynamics potentially influence the sources of organic matter (e.g., terrestrial versus marine, or fresh material versus detrital material) entering marine food webs. Understanding the significance of the processes that influence marine food webs and ecosystems (e.g., terrestrial inputs, physical dynamics) is crucially important because trophic dynamics are a vital part of ecosystem integrity. This can be achieved by identifying organic matter sources that enter food webs along inshore–offshore transects. We hypothesised that regional hydrological structures over wide continental shelves directly control the benthic trophic functioning across the shelf. We investigated this issue along two transects in the northern ecosystem of the Bay of Biscay (north-eastern Atlantic). Carbon and nitrogen stable isotope analysis (SIA) and fatty acid analysis (FAA) were conducted on different complementary ecosystem compartments that include suspended particulate organic matter (POM), sedimentary organic matter (SOM), and benthic consumers such as bivalves, large crustaceans and demersal fish. Samples were collected from inshore shallow waters (at ∼1 m in depth) to more than 200 m in depth on the offshore shelf break. Results indicated strong discrepancies in stable isotope (SI) and fatty acid (FA) compositions in the sampled compartments between inshore and offshore areas, although nitrogen SI (δ15N) and FA trends were similar along both transects. Offshore the influence of a permanently stratified area (described previously as a “cold pool”) was evident in both transects. The influence of this hydrological structure on benthic trophic functioning (i.e., on the food sources available for consumers) was especially apparent across the northern transect, due to unusual carbon isotope compositions (δ13C) in the compartments. At stations under the cold pool, SI and FA organism compositions indicated benthic trophic functioning based on a microbial food web, including a significant contribution of heterotrophic planktonic organisms and/or of SOM, notably in stations under the cold pool. On the contrary, inshore and shelf break areas were characterised by a microalgae-based food web (at least in part for the shelf break area, due to slope current and upwelling that can favour fresh primary production sinking on site). SIA and FAA were relevant and complementary tools, and consumers better medium- to long-term system integrators than POM samples, for depicting the trophic functioning and dynamics along inshore–offshore transects over continental shelves.

Geological Evolution of Coastal and Marine Environments off the Campania Continental Shelf Through Marine Geological Mapping - The Example of the Cilento Promontory

The geological evolution of coastal and marine environments offshore the Cilento Promontory through marine geological mapping is discussed here. The marine geological map n. 502 “Agropoli,” located offshore the Cilento Promontory (southern Italy), is described and put in regional geologic setting. The study area covers water depths ranging between 30 and 200 m isobaths. The geologic map has been constructed in the frame of a research program financed by the National Geological Survey of Italy (CARG Project), finalized to the construction of an up-to-date cartography of the Campania region. Geological and geophysical data on the continental shelf and slope offshore the southern Campania region have been acquired in an area bounded northward by the Gulf of Salerno and southward by the Gulf of Policastro. A high-resolution multibeam bathymetry has permitted the construction of a digital elevation model (DEM). Sidescan sonar profiles have also been collected and interpreted, and their merging with bathymetric data has allowed for the realization of the base for the marine geologic cartography. The calibration of geophysical data has been attempted through sea-bottom samples. The morpho-structures and the seismic sequences overlying the outcrops of acoustic basement reported in the cartographic representation have been studied in detail using single-channel seismics. The interpretation of seismic profiles has been a support for the reconstruction of the stratigraphic and structural setting of the Quaternary continental shelf successions and the outcrops of rocky acoustic basement in correspondence to the Licosa Cape morphostructural high. These areas result from the seaward prolongation of the stratigraphic and structural units, widely cropping out in the surrounding emerged sector of the Cilento Promontory. The cartographic approach is based on the recognition of laterally coeval depositional systems, interpreted in the frame of system tracts of the Late Quaternary depositional sequence.

Facoemulsificación : técnica quirúrgica oftalmológica realizada en el hospital veterinario de equinos durante el periodo de práctica rotatoria en la Universidad de Sao Paulo

Tesis (Médico Veterinario). -- Universidad de La Salle. Facultad de Ciencias Agropecuarias. Programa de Medicina Veterinaria, 2013

Convenio que Celebra la Escola Superior de Agricultura "Luiz de Queiroz" Da Universidade de Sao Paulo (Brasil) y la Universidad de Cuenca (Ecuador), por interés de Facultad de Ciencias Químicas/Carrera de Ingeniería Ambiental, teniendo como objetivo la cooperación académica para el intercambio de docentes/investigadores, estudiantes y miembros del equipo técnico-administrativo

Español

Retrievals of a size parameter for phytoplankton and spectral light absorption by colored detrital matter from water-leaving radiances at SeaWiFS channels in a continental shelf region off Brazil

Many efforts are currently oriented toward extracting more information from ocean color than the chlorophyll a concentration. Among biological parameters potentially accessible from space, estimates of phytoplankton cell size and light absorption by colored detrital matter (CDM) would lead to an indirect assessment of major components of the organic carbon pool in the ocean, which would benefit oceanic carbon budget models. We present here 2 procedures to retrieve simultaneously from ocean color measurements in a limited number of bands, magnitudes, and spectral shapes for both light absorption by CDM and phytoplankton, along with a size parameter for phytoplankton. The performance of the 2 procedures was evaluated using different data sets that correspond to increasing uncertainties: ( 1) measured absorption coefficients of phytoplankton, particulate detritus, and colored dissolved organic matter ( CDOM) and measured chlorophyll a concentrations and ( 2) SeaWiFS upwelling radiance measurements and chlorophyll a concentrations estimated from global algorithms. In situ data were acquired during 3 cruises, differing by their relative proportions in CDM and phytoplankton, over a continental shelf off Brazil. No local information was introduced in either procedure, to make them more generally applicable. Over the study area, the absorption coefficient of CDM at 443 nm was retrieved from SeaWiFS radiances with a relative root mean square error (RMSE) of 33%, and phytoplankton light absorption coefficients in SeaWiFS bands ( from 412 to 510 nm) were retrieved with RMSEs between 28% and 33%. These results are comparable to or better than those obtained by 3 published models. In addition, a size parameter of phytoplankton and the spectral slope of CDM absorption were retrieved with RMSEs of 17% and 22%, respectively. If these methods are applied at a regional scale, the performances could be substantially improved by locally tuning some empirical relationships.

Pleistocene mammals from the southern Brazilian continental shelf

Fossils of terrestrial mammals preserved in submarine environment have been recorded in several places around the world. In Brazil such fossils are rather abundant in the southernmost portion of the coast, associated to fossiliferous concentrations at depths up to 10 m. Here is presented a review of such occurrences and the first record of fossils in deeper areas of the continental shelf. The fossils encompass several groups of both extinct and extant mammals, and exhibit several distinct taphonomic features, related to the marine environment. Those from the inner continental shelf are removed and transported from the submarine deposits to the coast during storm events, thus forming large konzentrat-lagerstatte on the beach, called "Concheiros". The only fossils from deeper zones of the shelf known so far are a portion of a skull, a left humerus and of a femur of Toxodon sp. and a lower right molar of a Stegomastodon waringi, all collected by fishermen at depths around 20 m. The presence of fossils at great depths and distances from the present coastline, without signs of abrasion and far from areas of fluvial discharges does indicate that these remains have not been transported from the continent to the shelf, but have been preserved directly on the area that today correspond to the continental shelf. These remains indicate the existence of large fossiliferous deposits that have developed during periods of sea-level lowstand (glacial maxima) and have been submerged and reworked by the sea-level rise at the end of the last glaciation. (C) 2010 Elsevier Ltd. All rights reserved.

Heat fluxes between the Guadalquivir river and the Gulf of Cádiz Continental Shelf

An 18-year time series of daily sea surface temperature of Gulf of Cadiz and an 18-month time series of temperature collected in the vicinity of the Guadalquivir estuary mouth have been analyzed to investigate the heat exchange between the estuary and the adjacent continental shelf. The first time identifies a continental shelf area where seasonal thermal oscillation signal (amplitudes and phase) changes abruptly. In order to explain this anomaly, the second data set allows a description of thermal fluctuations in a wide range of frequencies and an estimation of the upstream heat budget of the Guadalquivir estuary. Results show that high frequency thermal signal, diurnal and semidiurnal, and water flux signal through Guadalquivir mouth, mainly semidiurnal, apparently interact randomly to give a small exchange of thermal energy at high frequency. There is no trace, at the estuary's mouth, of daily heat exchanges with intertidal mudflats probably because it tends to cancel on daily time scales. Results also show that fluctuations of estimated air-sea fluxes force fluctuations of temperature in a quite homogeneous estuarine, with a delay of 20 days. The along-channel thermal energy gradient reaches magnitudes of 300-400 J m-4 near the mouth during the summer and winter and drives the estuary-shelf exchange of thermal energy at seasonal scale. Particularly, the thermal heat imported by the estuary from the shelf area during late fall-winter-early spring of 2008/2009 is balanced by the thermal heat that the estuary exports to the shelf area during late spring-summer of 2008. In summary, Guadalquivir river removes/imports excess of thermal energy towards/from the continental shelf seasonally, as a mechanism to accommodate excess of heat from one side respect to the other side.

Exploring the Alentejo continental shelf for minerals and Quaternary environmental changes: preliminary results of the MINEPLAT survey.

This study presents the preliminary results of MINEPLAT survey, organized by Universidade de Évora in partnership with Instituto Português do Mar e da Atmosfera (IPMA) based on an integrated analysis of geophysical data namely, ultra-high resolution seismic data (UHRS), multibeam data, backscatter data and magnetic data. The survey took place on north Alentejo continental shelf (30 to 200 meters depth) between Tróia and Sines. The interpretation and integration of the acquired data allows substantial improvement on the knowledge on the morphology and geology of the surface and subsurface of the Alentejo continental shelf towards the assessment of the mineral resources potential in the continental shelf off Alentejo and of the environmental conditions caused by the tectonic uplift in the Pliocene-Quaternary.