Search results for "Salinity"

Sulfur cycling and methanogenesis primarily drive microbial colonization of the highly sulfidic Urania deep hypersaline basin

2009

Urania basin in the deep Mediterranean Sea houses a lake that is >100 m deep, devoid of oxygen, 6 times more saline than seawater, and has very high levels of methane and particularly sulfide (up to 16 mM), making it among the most sulfidic water bodies on Earth. Along the depth profile there are 2 chemoclines, a steep one with the overlying oxic seawater, and another between anoxic brines of different density, where gradients of salinity, electron donors and acceptors occur. To identify and differentiate the microbes and processes contributing to the turnover of organic matter and sulfide along the water column, these chemoclines were sampled at a high resolution. Bacterial cell numbers…

Seed germination of six coastal plant species of the Baltic region: effect of salinity and dormancy-breaking treatments

2008

AbstractSeed salinity tolerance and dormancy play important roles in germination behaviour. The effects of NaCl concentration and different dormancy-breaking treatments on germination were determined for six species growing on the coasts of the Baltic Sea or the Gulf of Riga: Juncus balticus, Triglochin maritima, Triglochin palustre, Anthyllis maritima, Linaria vulgaris and Linaria loeselii. Germination percentages were significantly reduced at NaCl concentrations >100 mM. Germination of J. balticus, T. maritima and T. palustre, but not that of A. maritima and L. vulgaris, recovered after seeds were rinsed with distilled water. Seeds of J. balticus were non-dormant; those of A. maritima …

Salinity gradient heat engines: An innovative concept for waste heat valorization

2022

Abstract The world population has grown rapidly in the last century and a similar increase is expected in the next years. A corresponding increase in energy production and consumption has been recorded so far and most of it comes from nonrenewable sources. The shift from conventional energy production processes to renewable-based ones is proceeding slowly; meanwhile, the need for reducing the energy losses in current power technologies is a matter of crucial importance. Thus, the interest toward low-grade waste heat and strategies for its valorization has rapidly grown recently. Salinity gradient heat engines are a novel promising technology to produce power from waste heat at very low temp…

Long-term competitive dynamics of two cryptic rotifer species: diapause and fluctuating conditions.

2015

Life-history traits may have an important role in promoting species coexistence. However, the complexity of certain life cycles makes it difficult to draw conclusions about the conditions for coexistence or exclusion based on the study of short-term competitive dynamics. Brachionus plicatilis and B. manjavacasare two cryptic rotifer species co-occurring in many lakes on the Iberian Peninsula. They have a complex life cycle in which cyclical parthenogenesis occurs with diapausing stages being the result of sexual reproduction. B. plicatilis and B. manjavacasare identical in morphology and size, their biotic niches are broadly overlapping, and they have similar competitive abilities. However,…

The use of constructed wetlands for the treatment and reuse of urban wastewater for the irrigation of two warm-season turfgrass species under Mediter…

2017

Constructed wetlands (CWs) represent low-cost technology for the treatment and reuse of wastewater in urban areas. This study aimed to evaluate the pollutant removal efficiency of a CW system and to assess the effects of irrigation using treated urban wastewater on soil and on two warm-season turf species. The research was carried out in Sicily (Italy) on a pilot-scale horizontal subsurface flow system which was fed with treated urban wastewater following secondary treatment from an activated-sludge wastewater treatment plant. The pilot system was located in an open urban park and comprised two separate parallel planted units. Experimental fields of Cynodon dactylon (L.) Pers. and Paspalum …

Plant response to irrigation with saline water in a Sicilian vineyard: results of a 3- year field investigation

2010

Life on the edge: Adaptations of Posidonia oceanica to hypersaline conditions in a Mediterranean lagoon system

2023

Hypersaline stress is a major stressor in semi-enclosed coastal lagoons, affecting the distribution and survival of key foundation species. In this study, we investigated how Posidonia oceanica meadows responded physiologically and morphologically to different salinity concentrations both in-situ, across a natural saline gradient occurring inside the lagoon system, and in a mesocosm experiment. Leaf water relations, organic osmolytes, photosynthesis, respiration, Chlorophyll-a fluorescence, pigments content, and leaf growth were studied in P. oceanica from three different sites within the Stagnone of Marsala lagoon, as well as after exposing P. oceanica to a salinity level of 46 psu in a 30…

Seagrass meadows at the extreme of environmental tolerance: the case ofPosidonia oceanicain a semi-enclosed coastal lagoon

2009

Atoll-like structures of the endemic Mediterranean seagrass Posidonia oceanica were encountered in the innermost area of the Stagnone di Marsala, a semi-enclosed coastal lagoon along the western coasts of Sicily. The area is characterized by limited water exchange with the open sea and by a marked seasonal variation of water salinity and temperature, reaching beyond the theoretical tolerance limits of the species. In the present study we determined the genetic composition of the atoll-like structures, as well as the growth performance and flowering rate of these stands. We also assessed whether and to what extent the atoll-like structures are genetically isolated from plants growing in mead…

Aquaculture effects on some physical and chemical properties of the water column: A meta-analysis

2007

More than 30 peer-reviewed articles (1980–2005) were analysed using meta-analytical reviewing techniques, and about 340 study cases were used to test whether aquaculture facilities had any effects on physical and chemical variables. The analysis tested differences between experimental conditions vs. chosen-by-author controls. Across all study cases, cultivated organisms (fish, shrimps and bivalves) did not have any clear effects on the water temperature and salinity. Dissolved oxygen also was found to be unaffected by aquaculture practices. On the other hand, crowding led to significant pH variations, which was more accentuated in shrimp (d+ = 0.66;P 0.05).Water transparency and turbidity w…

Effect of salinity and temperature on feeding physiology and scope for growth of an invasive species (Brachidontes pharaonis - MOLLUSCA: BIVALVIA) wi…

2008

Abstract The Indo-Pacific mytilid Brachidontes pharaonis (Bivalvia, Fischer 1870) offers an excellent model for the study of “Lessepsian migration” and the successive colonization at new Mediterranean locations. This species in out competing indigenous bivalves is particularly well adapted to Mediterranean conditions and this is likely due to biological characteristics and physio-ecological plasticity. In the present paper, we report on clearance rate (CR), respiration rate (RR) and Scope for Growth (SFG) of B. pharaonis collected from a Western Sicilian pond (Southern Tyrrhenian, MED). Physiological variables were determined in response to a range of temperatures from 11 ° to 20 °C and a b…