Search results for "table"
showing 10 items of 2807 documents
Contamination by trace metals and their trophic transfer to the biota in a Mediterranean coastal system affected by gull guano
2013
Transitional environments are vulnerable interface systems, ecologically connected with adjacent systems by several biotic or abiotic flows. The coastal system of the Marinello ponds (Tyrrhenian Sea, Italy) is affected by a colony of yellow-legged gulls Larus michahellis (Naumann, 1840), resident on the cliff beside the ponds. To investigate the role of the gull colony as a potential source of allochthonous non-essential trace metals (As, Cd, Pb and total mercury, THg) and the consequent metal trophic transfer to the biota in the ponds, we collected guano, surface sediment and biota from 3 ponds with different levels of avian input. The highest concentrations were observed in guano and surf…
Pedogenic carbonates and carbon pools in gypsiferous soils of a semiarid Mediterranean environment in south Italy
2013
Abstract Soil carbonates are key features in soils of arid and semiarid environment, playing an important role from pedogenetic, landscape history, paleoclimatic and environmental points of view. The objectives of this work were (i) to study pathways of pedogenic carbonate (PC) formation, (ii) to distinguish between lithogenic and pedogenic inorganic C by using the natural C isotope abundance, and (iii) to estimate the soil C pools in a gypsiferous semiarid Mediterranean environment (Sicily, Italy). Five soil pedons developed on calcareous and non-calcareous parent materials from Holocene (10,000 years BP) to Upper Tortonian (7.2–5.3 Ma BP) in age were surveyed. During field soil descriptio…
Sometimes Sperm Whales (Physeter macrocephalus) Cannot Find Their Way Back to the High Seas: A Multidisciplinary Study on a Mass Stranding
2011
BackgroundMass strandings of sperm whales (Physeter macrocephalus) remain peculiar and rather unexplained events, which rarely occur in the Mediterranean Sea. Solar cycles and related changes in the geomagnetic field, variations in water temperature and weather conditions, coast geographical features and human activities have been proposed as possible causes. In December 2009, a pod of seven male sperm whales stranded along the Adriatic coast of Southern Italy. This is the sixth instance from 1555 in this basin.Methodology/principal findingsComplete necropsies were performed on three whales whose bodies were in good condition, carrying out on sampled tissues histopathology, virology, bacter…
Isotope evidence for the use of marine resources in the Eastern Iberian Mesolithic
2014
There are relatively few coastal Mesolithic sites in the Iberian Mediterranean region, probably due to a number of factors including sea level changes and the disappearance of sites due to agriculture and urbanisation. However, recent excavations have uncovered inland sites that have marine faunal remains (i.e. molluscs and fish) and lithics from the coastal area, which both indicate interactions between the coast and the upland valleys. These inland sites are located at a distance of 30-50km from today's coastline and are at altitudes higher than 1000m. We report on additional information on the links between the coast and these inland sites through the use of dietary isotope analysis (car…
Gull-derived trace elements trigger small-scale contamination in a remote Mediterranean nature reserve
2013
The role of a yellow-legged gull (Larus michahellis) small colony in conveying trace elements (As, Cd, Cr, Cu, Ni, Pb, THg, V, Zn) was assessed in a Mediterranean nature reserve (Marinello ponds) at various spatial and temporal scales. Trace element concentrations in guano were high and seasonally variable. In contrast, contamination in the ponds was not influenced by season but showed strong spatial variability among ponds, according to the different guano input. Biogenic enrichment factor B confirmed the role of gulls in the release of trace elements through guano subsidies. In addition, comparing trace element pond concentrations to the US NOAA’s SQGs, As, Cu and Ni showed contamination …
Analysis of the trophic role of Mediterranean seagrasses in marine coastal ecosystems: a review
2009
Abstract Seagrasses form high-productivity coastal ecosystems, providing habitats for many organisms, including species of commercial value. They play a significant role as a direct food source for herbivores and also enter detrital food webs. In this review, the trophic ecology of Mediterranean seagrass ecosystems is revised, with major emphasis on Posidonia oceanica, the most extensively studied seagrass. The major topics are the role of herbivory and detritus, the contribution to littoral fish production, exportation to other ecosystems and the seagrass role as a vector of anthropogenic nutrients into food webs. Topics are discussed by analysing both conventional knowledge and new insigh…
Effects of a small seagull colony on trophic status and primary production in a Mediterranean coastal system (Marinello ponds, Italy)
2012
Abstract Colonies of seabirds have been shown to influence nutrient cycling and primary production of coastal areas, but knowledge is still limited above all for smaller colonies. This study evaluates the influence of a small resident seagull colony (Larus michahellis Naumann, 1840) on a Mediterranean coastal system (Marinello ponds, Sicily, Italy). The presence of ornithogenic organic matter from seagull guano was first assessed at increasing distances from the colony using δ15N to indicate the effects of guano on the trophic status and primary production. The pond directly affected by guano deposition showed an anomalous water and sediment chemistry, especially regarding physico-chemical …
Stable C and N isotope concentration in several tissues of the loggerhead sea turtle Caretta caretta from the western Mediterranean and dietary impli…
2007
CONCENTRACIÓN DE ISÓTOPOS ESTABLES DE C Y N EN VARIOS TEJIDOS DE LA TORTUGA BOBA CARETTA CARETTA DEL MEDITERRÁNEO OCCIDENTAL E IMPLICACIONES SOBRE LA DIETA. – La concentración isotópica de escudos del caparazón, piel, músculo y sangre de tortuga boba (Caretta caretta) fueron analizados para investigar el patrón de variación entre tejidos y para evaluar la posición de esta especie en las redes tróficas de la cuenca Argelina. La piel presentaba valores más altos de δ13C que el músculo o los escudos del caparazón y éstos presentaban valores más altos que la sangre. En cambio, el músculo presentaba valores más altos de δ15N que la piel, ésta valores más altos que la sangre y ésta valores más al…
Surface and deep water conditions in the Sicily channel (central Mediterranean) at the time of sapropel S5 deposition
2011
New centennial-scale data of benthic foraminifera assemblages and of stable isotopes of foraminifera shells from the Sicily Channel, representative of surface and bottom waters, over the interval between about 140 and 110 kyr BP, are presented. During this period anoxia developed on the eastern Mediterranean basin and sapropel S5 deposited. Although anoxic sediments have not been deposited in the Sicily Channel, this area is strategic to study the character of intermediate waters, whose chemical-physical properties strongly precondition the eastern Mediterranean deep water formation. So far, no data from these water masses have been obtained, apart from the isotopic composition of shells of…
SOIL QUALITY INDICATORS AS AFFECTED BY SHALLOW TILLAGE IN A VINEYARD GROWN IN A SEMIARID MEDITERRANEAN ENVIRONMENT
2016
Within the Mediterranean basin, soil tillage enhances the mineralisation of soil organic matter. We assessed the short-term impact of shallow tillage [field cultivator (FC), rotary tiller (RT) and spading machine (SM)] on some soil quality indicators [bulk density, water-stable aggregates, total and labile organic C pools (microbial biomass and extractable organic C), soil respiration and related eco-physiological indexes] in a Sicilian vineyard. Also no tillage was included. We hypothesized that (i) RT and FC worsened soil quality indicators more than SM, and (ii) within the same tillage system, labile C pools, soil respiration and eco-physiological indexes will respond more efficiently th…