Search results for " Lago"

Comparing the dynamic performance of wastewater treatment systems: A metafrontier Malmquist productivity index approach

2015

The assessment of productivity change of wastewater treatment plants (WWTPs) is essential to improve the performance over time of the facilities evaluated. This study assessed and compared the productivity growth of WWTPs operating with non-homogeneous technologies. The metafrontier Malmquist productivity index (MMPI) was computed for a sample of 99 WWTPs encompassing 4 alternative technologies: activated sludge (AS), aerated lagoon (AL), trickling filter (TF) and rotating biological contactor (BD). The results indicated that, on average, WWTPs with AS and BD exhibited better performance over time than WWTPs with AL and TF. The MMPI indicates that, over the period 2007-2009, the productivit…

Concentration of retene and resin acids in sedimenting particles collected from a bleached kraft mill effluent receiving lake

2000

Abstract The concentration of retene, a di-alkyl substituted PAH derived microbially and thermally from dehydroabietic acid, eight resin acids and their derivatives were analysed from sedimenting particles collected from five lake sites receiving pulp and paper mill effluents and from two reference sites. At five of the sites, samples were collected prior and after a conventional aerated lagoon wastewater treatment system of the mill was modernized with an activated sludge plant, and elemental chlorine free bleaching (ECF) had replaced chlorine bleaching. The highest level of retene was 30.0–53.8  μ g/g dry weight (d.w.), observed 3 km downstream from the mill. Nine kilometers downstream fr…

Effect of substrate and seagrass habitat complexity on detritus colonization and decomposition in a Mediterranean coastal lagoon (Thau Lagoon, France…

2019

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…

Biological characteristics of three Brachyuran crab species in the Lagoon of Elbibane, South-Eastern Tunisia

2016

This study is a first contribution to the knowledge of the biology of three crab species, Carcinus aestuarii, Eriphia verrucosa and Pachygrapsus marmoratus, occurring in the intertidal zone of Elbibane lagoon, south-eastern Tunisia. A total of 1264 individuals from the three brachyuran species were collected monthly from April 2010 until March 2011 and their reproduction and growth parameters were determined. The seasonal distribution of carapace width showed for the three species that males have always a greater size than females. The length-weight relationship showed in the three species a negative allometry in males, and in non-ovigerous females. The von Bertalanffy growth model (VBGF) p…

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…

Spatial variability of macrozoobenthic community and trophic structure of a subtropical lagoon in the Southeastern Atlantic coast

2013

The Effect of Temporal Changes and Environmental Trophic Condition on the Isotopic Composition (omega13C and omega15N) of Atherina boyeri (Risso, 181…

2002

δ13C and δ15N of organic matter sources and consumers were employed to analyse trophic differentiation between a benthic consumer, Gobius niger (L., 1758) (Pisces, Osteichthyes), and a pelagic consumer, Atherina boyeri (Risso, 1810) (Pisces, Osteichthyes) in a Mediterranean coastal lagoon (Lake of Sabaudia) in winter and summer 1999. Trophic differences between the two species throughout the two sampling periods were related to the environmental trophic condition (i. e. nutrient and phytopigment concentrations). Although these two fish have different habitats, they both exploited benthic organisms, above all in summer. When the nutrient and phytopigment concentrations were higher (summer), …

Valuing the unmarketable: an ecological approach to the externalities estimate in fishing activities

2013

In a rapidly changing world, sustainability, if it can be said to exist at all, is concept that has attained mythic status, often pursued and rarely reached. In order to improve our capability to cope with environmental problems, adopting an Ecosystem Approach has been suggested. One of the major challenges in the implementation of this new paradigm relates to control of externalities. The recognition and quantification of externalities is often cast as valuing the unmarketable, and there are several approaches that have been proposed. Here, we analyze the opportunity to “feed” the economic valuation with ecological concepts. From an ecological perspective, the energy required to sustain a …

Trophic adaptability shapes isotopic niche of the resident fish Aphanius fasciatus across lagoon habitats

2022

Abstract Coastal lagoons are characterized by high habitat heterogeneity where natural habitats coexist with artificial ones, historically set up to support human activities. Increasing anthropogenic pressure may lead to progressive degradation of the most vulnerable lagoonal habitats and the associated biological communities. One of the strictly estuarine-dependent fish species that may be affected by the degradation of lagoon habitats is the South European toothcarp Aphanius fasciatus, archetype of Mediterranean lagoon residents. Carbon and nitrogen stable isotopes were used to disentangle the influence of habitat types (natural vs artificial) and fish community (multi-trophic context) on…