182 resultados para NORTHWESTERN SPAIN
Resumo:
Zooplankton was sampled by project RADIALES at Vigo (E3VI) and A Coruña (E2CO) between 1994 and 2006. Samples were collected using 50-cm diameter Juday-Bogorov (A Coruña) or 40-cm diameter bongo plankton nets (Vigo) equipped with 200-µm mesh size. Tows were double oblique from surface to near bottom (90 and 70 m in Vigo and A Coruña, respectively). All samples were collected between 10:00 and 14:00 o'clock (local time). Samples were preserved in 2-4% sodium borate-buffered formaldehyde. For the purpose of this study, the original coastal time series were categorized in copepods representative of crustacean zooplankton) and gelatinous plankton (medusae and tunicates). Medusae included Hydrozoans and Scyphozoa, and tunicates included salps, pyrosomes, doliolids, and appendicularia. Plankton identification and counts were performed by Ana Miranda and M. Teresa Álvarez-Ossorio for samples from Vigo and A Coruña, respectively. Different trends were found for gelatinous plankton in the two coastal sites, characterized by increases in either medusae or tunicates. Multiyear periods of relative dominance of gelatinous vs. copepod plankton were evident. In general, copepod periods were observed in positive phases of the main modes of regional climatic variability. Conversely, gelatinous periods occurred during negative climatic phases. However, the low correlations between gelatinous plankton and either climatic, oceanographic, or fishery variables suggest that local factors play a major role in their proliferations.
Resumo:
Neogene deposits from Belorado (Province de Burgos, Spain) in the NE border of the Duero Basin have been analyzed. The palynologic analysis of the samples suggests the existence of arboreal landscapes associated with the herbaceous cover creating belts of vegetation around restricted aquatic areas (marshy and lacustrine environments). The characteristics of the palynomorph assemblages allow to define a warm-template climate with strong seasons. The age of these deposits could be included in the middle Miocene (Aragonian).
Resumo:
Concentrations of adenosine triphosphate (ATP), urea, and dissolved organic carbon in bottom water are shown to be considerable, sometimes several times higher than in the photic and surface layers of the ocean. Urea and ATP concentrations are inversely proportional. Identified biochemical characteristics of bottom water are of great importance in determining the status of the aquatic environment. The highest life activity (maximum ATP content) in bottom water appeared in the vicinity of faults in rift zones of the ocean, where high gas concentrations were also found. Population of chemoautotrophic microorganisms was clearly present under these conditions. Biochemical investigations provide additional criteria for identifying oil and gas prospects. They are also of definite interest in combination with gasometric determinations, which will undoubtedly give us deeper understanding of processes of formation of oil and gas and will help in finding them.
Resumo:
Distributions of Mn, Fe, Cu, Cd, Cr, Co and Ni in sea water are investigated (42 samples, dissolved and particulate forms) in the vicinity of the underwater gas vent field on the northwestern slope of the Paramushir Island. While regular background distributions of the elements occur in the shore zone, there is a column of elevated concentrations of particulate matter, particulate Mn, and dissolved Mn, Fe, Cu, Cd, Cr, Co and Ni that coincides with location of the gas plume. This column can be traced as high as 780 m above the bottom. High metal concentrations in water of the plume are attributable to physico-chemical concentration at the phase interface; the source of elevated mineral concentrations is obviously flux of dissolved minerals from interstitial waters, which extends to considerable distances in vertical direction.
Resumo:
Distribution of urea in different water layers of the northwestern Indian Ocean is described. It was found to be non-uniformly distributed. High concentration was found in waters close to the bottom. Urea may serve as an indicator of state of the water environment.