Search results for "Salinity"
showing 10 items of 374 documents
Freshening of the Mediterranean Salt Giant: controversies and certainties around the terminal (Upper Gypsum and Lago-Mare) phases of the Messinian Sa…
2021
The late Miocene evolution of the Mediterranean Basin is characterized by major changes in connectivity, climate and tectonic activity resulting in unprecedented environmental and ecological disruptions. During the Messinian Salinity Crisis (MSC, 5.97-5.33 Ma) this culminated in most scenarios first in the precipitation of gypsum around the Mediterranean margins (Stage 1, 5.97-5.60 Ma) and subsequently > 2 km of halite on the basin floor, which formed the so-called Mediterranean Salt Giant (Stage 2, 5.60-5.55 Ma). The final MSC Stage 3, however, was characterized by a "low-salinity crisis", when a second calcium-sulfate unit (Upper Gypsum; substage 3.1, 5.55-5.42 Ma) showing (bio)geochemica…
Ages and stratigraphical architecture of late Miocene deposits in the Lorca Basin (Betics, SE Spain): New insights for the salinity crisis in margina…
2020
International audience; Unlike most Neogene basins of the Betic Cordillera where the Salinity Crisis is dated to the Messinian, a contradictory Tortonian dating was proposed for evaporites of the Lorca Basin. As a consequence, complex structural models have been proposed in the literature to explain this discrepancy in the timing of evaporites. In order to integrate the Lorca Basin into the geological context of the western Mediterranean domain during the Late Miocene, new sedimentological and stratigraphical studies coupled with new dating were performed, which allow us to propose a Messinian age for both diatomite-bearing deposits and evaporites of the Lorca Basin. These new ages challeng…
Ostracod palaeolimnological analysis reveals drastic historical changes in salinity, eutrophication and biodiversity loss in a coastal Mediterranean …
2013
The Albufera of Valencia, one of the largest oligohaline coastal lagoons of the Iberian Peninsula, has suffered hydrological and landscape modifications since medieval times. This paleolimnological study clears up the controversy about the factors, which drove the lake to its present state. Lithological descriptions, ostracod paleoassemblages and Cyprideis torosa (Jones, 1850) shell morphological variations and geochemistry (δ18O, δ13C and Sr/Ca) have been used to reconstruct the lake ecosystem evolution during the last two centuries. The sandy sediments at the bottom of L’Antina core (63 cm) presented a typical assemblage of brackish water ostracods, with shell-derived δ18O values, inferre…
Effects of salinity and water temporality on zooplankton community in coastal Mediterranean ponds
2012
Abstract Some of the predicted effects of climate warming in Mediterranean climate are the increase of temperature, change of precipitation patterns and the rise in sea levels. This will have major consequences, mainly in coastal aquatic ecosystems, by the increase of salinity and the reduction of the flooding period, affecting the whole aquatic community. To assess on the possible consequences of the global change in the zooplankton community of Mediterranean coastal lakes, we analized the zooplankton diversity in a set of lakes with different salinity and water permanence time. The ponds were classified in four groups: permanent and temporary freshwater ponds, and permanent and temporary …
Effects of temperature, salinity and food level on the life history traits of the marine rotifer Synchaera cecilia valentina, n. subsp.
1997
A strain of the marine rotifer Synchaeta cecilia valentina, n. subsp., isolated from the Hondo of Elche Spanish Mediterranean coastal lagoon at 22%o salinity, was cultured in the laboratory in 20 ml test tubes and fed with the alga Tetraselmis suecica. The effect of two temperatures (20 and 24°C), four salinities (20,25,30 and 37%o) and two food levels (15 000 and 25 000 cells ml-1) on the life history traits of this rotifer were studied in life tables performed with replicated individual cultures. Temper- ature and salinity had a significant negative effect (P < 0.001) on the average lifespan (LS) and on the number of offspring per female (RQ). The effect of food level on LS is unclear, wh…
Grasslands and Shrublands of the Mediterranean Region
2020
The Mediterranean Region extends to the 1.6% of the world’s land surface and more than the half of the Mediterranean-type ecosystems of the world. The remarkable species richness in the Mediterranean Region mainly originates from an exceptional habitat diversity and the presence of several natural barriers facilitating the segregation and differentiation of local taxa and biocoenoses. In this article, we deal with the habitats characterized by grasslands and shrublands that clearly show the adaptations to what could be called “the Mediterranean syndrome”, i.e., the intrazonal Mediterranean grasslands and shrublands (MG&S). The main driving forces of the adaptive radiation and high biodi…
The age of vines as a controlling factor of soil erosion processes in Mediterranean vineyards
2018
Abstract Vineyards incur the highest soil and water losses among all Mediterranean agricultural fields. The state-of-the-art shows that soil erosion in vineyards has been primarily surveyed with topographical methods, soil erosion plots and rainfall simulations, but these techniques do not typically assess temporal changes in soil erosion. When vines are planted they are about 30 cm high × 1 cm diameter without leaves, the root system varies from 2 to over 40 cm depth, and sometimes the lack of care used during transplanting can result in a field with highly erodible bare soils. This means that the time since vine plantation plays a key role in soil erosion rates, but very little attention …
Multiple stressors in Mediterranean coastal wetland ecosystems : Influence of salinity and an insecticide on zooplankton communities under different …
2021
Temperature increase, salinity intrusion and pesticide pollution have been suggested to be among the main stressors affecting the biodiversity of coastal wetland ecosystems. Here we assessed the single and combined effects of these stressors on zooplankton communities collected from a Mediterranean coastal lagoon. An indoor microcosm experiment was designed with temperature variation (20 °C and 30 °C), salinity (no addition, 2.5 g/L NaCl) and the insecticide chlorpyrifos (no addition, 1 μg/L) as treatments. The impact of these stressors was evaluated on water quality variables and on the zooplankton comunity (structure, diversity, abundance and taxa responses) for 28 days. This study shows …
Recent trends of SST in the Western Mediterranean basins from AVHRR Pathfinder data (1985-2007)
2011
Climate change in the Mediterranean region cannot be understood without taking into account changes in the Mediterranean Sea, which is an important source of moisture and heat for the Mediterranean climate system. Many research papers have been published in the last two decades increasing our knowledge about long-term trends and inter-annual variability of temperature and salinity in the Western Mediterranean. Although recent changes have been better documented, there remain uncertainties because different results are obtained depending on the period of time analyzed or the geographic region selected. This paper analyses the regional, seasonal and decadal variability of sea surface temperat…
The role of charophytes in a Mediterranean pond created forrestoration purposes
2015
A small, shallow basin was created and flooded with groundwater in a Reserve Area in Albufera de València Natural Park (AVNP) under the scope of a restoration program intended to mimic typical environments such as freshwater springs, abundant in the past but currently suffering from deterioration (desiccation, pollution, etc.), with the ultimate goal of increasing local biodiversity of submerged macrophytes, particularly charophytes. In this study we have monitored, from April 2009 (a few months after its first flooding) to September 2012, the dynamics of charophyte growth and related physical, chemical and biotic variables to highlight the factors determining charophyte success. Just after…