936 resultados para Marine sciences


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The marine and estuarine ecosystems of South Australia are likely to alter significantly in response to a changing climate, but also in response to managerial decisions we make. The allocation of fishing effort is an example of one such decision. We summarise some projections on a state-wide basis for how different components of these ecosystems may be expected to change. We anticipate that tropical elements will expand in range but cold-temperate communities will contract or disappear from South Australia. As a specific example, we have modelled the ecosystem states of the Coorong and the Murray Mouth. We combined biological and physico-chemical components of an ecosystem into co-occurring units (termed ecosystem states) with well-defined thresholds between them. Predictions were then made using time series of inputs from modelled water flows and other predictors. Using this model, we will discuss the likely implication of a range of climate change and management scenarios, highlighting the potential impact on the commercial fishing opportunities. Specifically we will discuss the potential sensitivity of the fishery to climate changes versus various management options. Understanding these possible future changes should allow the industry to adapt before climate change reduces the sustainability of the industry.

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Libinia spinosa H. Milne Edwards in Guérin, 1832 and L. ferreirae Brito Capello, 1871, inhabit very similar environments, and their geographic and bathymetric distributions overlap for about 3000 km along the southwestern Atlantic. Both species are commonly caught in the same haul and differentiating between them can often be difficult. Traditionally, morphological differentiation between L. spinosa and L. ferreirae has been based exclusively on the number of spines along the median, longitudinal line of the carapace and the development of a process at the anterolateral angle of the basal segment of the antenna. Because Libinia spinosa and L. ferreirae share similar numbers of median spines (7 and 6, respectively), and the number of median spines of the carapace and the process at the anterolateral angle of the basal antennal segment are variable, they are of little value in separating these species. It is shown herein that unequivocal identification can be easily achieved based on features of the male and female thoracic sternum, pereiopod dactyli, and infraorbital notch. A lectotype is designated for L. spinosa and its authorship and date are corrected. Libinia gibbosa A. Milne-Edwards, 1878, is demonstrated to be a junior synonym of L. ferreirae. The holotype of L. gibbosa is figured for the first time.

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The outcrop of the underlying substratum of the Maspalomas dune field (Gran Canaria, Canary Islands): a sing of a sedimentary deficit

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[EN] Mesozooplankton organisms (>250 μm) were sampled at two stations (inner and outer Bay) in the Bay of Cádiz between May and July 2008. Samples were analysed by means of a semi-automated technique in order to give a preliminary view of the mesoozooplankton community structure in the Bay, based on taxonomic diversity and biomass distribution among size classes. The abundance of organisms increased from May to July in accordance with the increase in temperature and Chlorophyll a (Chla) concentrations. Abundances were higher in the outer Bay station, where Chla concentrations are greater and the water column is more stable. The community changed from being meroplankton- to holoplankton-based due to an increase of Calanoida and especially Cladocera individuals (mainly Peniliaavirostris), which are known to peak acutely in the summer. The analysis of Normalised Biomass-Size spectra revealed fairly steep slopes (average -1.3) and relatively high departures from steady state (r2 = 0.8 – 0.94), expectable in a coastal system such as the Bay of Cádiz were disturbance factors are introduced from benthic and tidal processes, together with anthropogenic pressure.

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[EN] Numerous specimens of fossil brachiopods have been found in the different fossiliferous outcrops of the Canary Islands. These fossils have been found in the deposits of Mio-Pliocene age of the eastern Canary Islands, described and illustrated in the work of Meco et ali. 2005 and in the outcrops interpreted as a tsunami deposits  in Piedra Alta, Lanzarote, belonging to the Marine Isotope Stage 11 dated to circa 330 ka. 4 species of fossil brachiopods have been identificated: Terebratula sinuous Brocchi 1814, Lacazella mediterranea Risso 1826 Terebratulina caputserpentis (Zbyszewski, 1957) and Thecidium cf . digitatum (Sowerby 1823). These fossils provides stratigraphic and paleoclimatic taxonomic information. Furthermore, in order to compare the fossil brachiopods with present in the Canary Island, a reference collection is defined with specimens obtained from marine sediment surveys at Gran Canaria, La Palma and El Hierro, identifying 3 species: Argyrotheca barrettiatia (Davidson, 1866), Megerlia truncata (Linaeus 1767 ) and Pajaudina atlantica (Logan 1988).

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[EN] The last 5 Myr  are characterized by cliamatic variations globally and are reflected in ancient fossiliferous marine deposits visible in the Canary Islands. The fossils contained are identificated as paleoecological and paleoclimatic indicators. The Mio-Pliocene Transit is represented by the coral Siderastrea micoenica Osasco, 1897; the gastropods Rothpletzia rudista Simonelli, 1890; Ancilla glandiformis (Lamarck, 1822); Strombus coronatus Defrance, 1827 and Nerita emiliana Mayer, 1872 and the bivalve Gryphaea virleti Deshayes, 1832 as most characteristic fossils  and typical of a very warm climate and littoral zone. Associated  lava flows  have been dated radiometrically  and provides a range between  8.9 and about 4.2 Kyr. In the mid-Pleistocene, about 400,000 years ago, the called Marine Isotope Stage 11, a strong global warming that caused a sea level rise happens. Remains of the MIS 11  are preserved on the coast of Arucas (Gran Canaria), and associated with a tsunami in Piedra Alta (Lanzarote). These fossilifeorus  deposits contains the bivalve Saccostrea cucullata (Born, 1780), the gastropod Purpurellus gambiensis (Reeve, 1845) and the corals Madracis pharensis (Heller, 1868) and Dendrophyllia cornigera (Lamarck, 1816). Both sites have been dated by K-Ar on pillow lavas (approximately 420,000 years) and by Uranium Series on corals (about 481,000 years) respectively. The upper Pleistocene starts with another strong global warming known as the last interglacial or marine isotope  stage (MIS) 5.5, about 125,000 years ago, which also left marine  fossil deposits exposed in parallel to current in Igueste of San Andrés (Tenerife),  El Altillo, the  city of Las Palmas de Gran Canaria  and Maspalomas (Gran Canaria),  Matas Blancas, the Playitas and Morrojable (Fuerteventura ) and in Playa Blanca and Punta Penedo (Lanzarote ). The fossil coral Siderastrea radians (Pallas , 1766 ) currently living in the Cape Verde Islands , the Gulf of Guinea and the Caribbean has allowed Uranium series dating. The gastropods Strombus bubonius Lamarck, 1822 and Harpa doris (Röding , 1798 ) currently living in the Gulf of Guinea. Current biogeography using synoptic data obtained through satellites provided by the ISS Canary Seas provides data of Ocean Surface Temperature (SST) and Chlorophyll a (Chlor a) . This has allowed the estimation of these sea conditions during interglacials compared to today .

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Degree in Marine Sciences. Faculty of Marine Sciences, University of Las Palmas de Gran Canaria. Institut de Ciències del Mar, Consejo Superior de Investigaciones Científicas

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Trabajo realizado por Sergio Sañudo-Wilhelmy, Danielle Monteverde and Laura Gomez-Consarnau

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[EN] Stommel has been the most important physicist oceanographer of the second half of the XX century. Builder, to a great extent, of the present Dynamical Oceanography. He contributed to the transformation of the Oceanography from a sort of appendix of the studies of the Atmosphere to a new specialty of Geophysics. After graduating in Astronomy in Yale in 1942 he started his research participating in the WWII effort, collaborating together with many other future oceanographers, in support of the USA Navy. Research that was carried out in the Woods Hole Oceanographic Institution (WHOI). Between 1959 and 1978 he was professor of oceanography in Harvard U. first, and later in the Massachusetts Institute of Technology, returning to WHOI where he stayed until his death. Stommel established important and fundamental theories on the ocean global circulation and studied many other oceanographic phenomena. This theoretical activity he combined with not a less important observational one. He received many awards and hhonors, including the Craadford prize, equivalent to the Nobel in Geosciences.

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[EN] The main types of submarine geological emissions are classified as cold seeps (hydrocarbons and brines) and hot vents. These processes result in the emission of geological fluids: brine, gases (mainly hydro-carbons), sediments and rocks. Submarine emissions are associated with an intensive geological, geo-chemical, thermal and biological activity (Judd and Hovland, 2007), and constitute a key process in the dynamics of the global cycles of the planet Earth.

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[EN] The editorial and review processes along the road to publication are described in general terms. The construction of a well-prepared article and the manner in which authors may maximise the chances of success at each stage of the process towards final publication are explored. The most common errors and ways of avoiding them are outlined. Typical problems facing an author writing in English as a second language, including the need for grammatical precision and appropriate style, are discussed. Additionally, the meaning of plagiarism, self-plagiarism and duplicate publication is explored. Critical steps in manuscript preparation and response to reviews are examined. Finally, the relation between writing and reviewing is outlined, and it is shown how becoming a good reviewer helps in becoming a successful author

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[ES] Fundado por el profesor Odón de Buen en 1914, el Instituto Español de Oceanografía ha cumplido 100 años de existencia. En esta presentación se hace una sucinta revisión de su trayectoria científica, desde sus orígenes hasta la actualidad, intentando identificar las situaciones históricas que la condicionaron. Finaliza con una exposición de los retos científicos potenciales a los que se enfrenta la institución en el futuro inmediato y con una reflexión sobre los riesgos que pudieran dificultar el cumplimiento de su misión.