Impact evaluation on groundwater of the infiltration of an urban wastewater geopurification system placed over a detrital aquifer in a semiarid region (Spain)

Over a period of 4 years and 4 months, the geopurification installations at Dehesas de Guadix (Granada, Spain) were monitored to determine the impact on soil and groundwater of the controlled discharge of urban wastewater, and also to identify the best indicators of the entry of the recharged water into the aquifer. The installations are located in an area where the climate is Mediterranean sub-arid, with an average precipitation of less than 287 mm/year, and a rate of evapotranspiration that is almost three times greater. The system was controlled by determining the balance of majority nutrients and boron in the soil and in the groundwater, both at the points affected directly by the wastewater discharge and at others. The quantity of mass discharged was relatively large (COD 14,656 g/m², NO₃ 85 g/m², NO₂ 4 g/m², NH₄ 2,425 g/m², PO₄ 1,143 g/m², K 1,531 g/m², B 63 g/m²). It was observed that the elimination of nutrients within the soil (COD 97.5%, PO₄ 94.4%, K 59.17%, N _total 18.8%, B 12.69%) was very efficient except for the nitrogen, which nevertheless did not reach the groundwater, as it was eliminated at deep levels of the unsaturated zone. Only 12.69% of the boron was removed, and appreciable, increasing amounts of this element did reach the groundwater. Unexpectedly, none of the majority nutrients behaved as a reliable indicator of the impact on groundwater; despite this, the boron and the bicarbonate did clearly reflect the arrival of the recharged water, and are proposed as the best indicators.     

Nutrients and zooplankton composition and dynamics in relation to the hydrological pattern in a confined Mediterranean salt marsh (NE Iberian Peninsula)

The role of the hydrological regime in the nutrients and zooplankton composition and dynamics has been analysed in five lagoons of La Pletera salt marshes (NE Iberian Peninsula) during a complete hydrological cycle (2002–2003). Two of the lagoons have their origin in the old river mouths while the other three were recently created in the framework of a Life Restoration project. This fact has also allowed us to study the effect of the lagoon age on nutrient and zooplankton composition and dynamics. The salt marsh hydrology is determined by a prolonged period of confinement without water inputs, irregularly interrupted by sudden water inputs due to flooding events (sea storms or intense rainfalls). While the dynamics of oxidized nitrogen compounds in the lagoons depends on the water inputs variability within each hydrological cycle, the internal load of phosphorus, total nitrogen and organic matter is related more to the cumulative mechanisms during the confinement periods. Accumulation processes may be easily related to lagoon age, since old lagoons have higher content of nutrients and organic matter, suggesting that these lagoons progressively accumulate nutrients during the successive confinement events. This is the usual case for most Mediterranean salt marshes without an artificially manipulated water regime. The zooplankton community in La Pletera integrates the effects of both the hydrological regime and the lagoon age since the former determines the temporal pattern of the main zooplankton species and the latter explains differences in composition and structure between old and new lagoons.     

Linking foraging behavior and diet in a diving seabird

Foraging behavior and diet of breeding seabirds may be analysed simultaneously with the combined use of remote sensing devices and stable isotope analysis. Imperial shag, Phalacrocorax atriceps, breeding at Punta León colony, Argentina, were equipped with global positioning system (GPS) loggers to record foraging trips and blood samples were taken after removal of the devices in order to analyse their nitrogen and carbon stable isotope composition in whole blood and plasma. Whole blood was correlated to plasma isotopic composition for each individual (n = 35), linking diet in the short and medium term. Sexes did not differ in isotopic signatures. The maximum distance reached and the total number of dives that individuals made on two consecutive foraging trips were correlated to their plasma nitrogen isotopic signature. Individuals that went further from the colony and dived fewer times presented more positive signatures, indicative of benthic prey consumption (e.g. Raneya brasiliensis). Diet was predominantly benthic with some individuals incorporating pelagic prey (Engraulis anchoita) and even cephalopods (Octopus tehuelchus). Within breeding pairs (n = 9), different combinations of foraging and prey preferences were observed. Estimated trophic levels of these individuals were similar to those of the same species in other colonies further south along the Patagonian coast.     

Statistical forecast of the marine surge

Natural Hazards - This paper studies different machine learning methods for solving the regression problem of estimating the marine surge value given meteorological data. The marine surge is...     

Tableau de répartition stratigraphique des Grands Foraminifères caractéristiques du Crétacé moyen de la région Méditerranéenne

Le Groupe de Travail Européen des Grands Foraminifères présente un tableau de répartition stratigraphique de 42 espèces bien définies du Crétacé moyen de la région méditerranéenne. La répartition stratigraphique proposée pour chaque espèce est fondée soit sur des propres observations soit sur des données de la littérature supprimer et est contrôlée par la présence d'Ammonites ou de Foraminifères planctoniques.A summarizing account is presented of the deliberations of the research group for Large Foraminifers of the IGCP Project “Mid-Cretaceous Events”. Large Foraminifers are of incontestable value for dating carbonate platform sequences owing to the absence of many other diagnostic groups of organísms. A table of stratigraphical distributions for 42 species is presented.     

Microbial biomass response to different quantities and sources of organic matter in Brazilian coastal sediments

This study investigates the benthic microbial responses to organic matter (OM) variations in quantity and sources in two shallow water bays (Fortaleza and Ubatuba Bays) on the SE coast of Brazil on six occasions during the year. The pelagic and benthic compartments of the bays were evaluated by: (i) nutrients and chlorophyll a (Chl a) in the water column; (ii) quantity and sources of OM in the sediment (Chl a, total organic carbon and total nitrogen and lipid biomarker composition); and (iii) microbial biomass in sediments as an indicator of active benthic response. Although there were changes in water‐column nutrients during the year, Chl a was fairly constant, suggesting a regular supply of microalgae‐derived OM to the sea bottom. Based on the composition of lipid biomarkers in sediments, OM sources were classified as mostly marine and with high contributions of labile (microalgae‐derived) OM. Labile OM composition varied from diatoms in the summer to phytoflagellates in the winter and tended to accumulate in areas protected by physical disturbances in one of the bays. Microbial biomass followed this trend and was 160% higher in protected than in exposed areas. This study suggests that the coupling between labile OM and benthic microbial biomass occurs primarily in protected areas, irrespective of the time of the year. Since meio‐ and macrofaunal assemblages depend upon secondary microbial production within the sediments, this coupling may have an important role for the benthic food‐web.     

Short-term effects of changes in water management on the limnological characteristics and zooplankton of a eutrophic Mediterranean coastal lagoon (NE Iberian Peninsula)

The Ter Vell (NE Iberian Peninsula) is a eutrophic coastal lagoon which has been flooded by the excess irrigation water and the agricultural runoff during the last decades. Between 1999 and 2003, restoration measures were applied to improve its water quality. At the same time, but independently, agricultural water management drastically reduced the freshwater inflow. The short-term effects of these management actions on the limnological characteristics of the lagoon were analysed by comparing two hydrological cycles, one before (1999/2000) and the other one after (2002/2003) the actions. The two cycles are illustrative of opposite situations in the hydrological functioning of coastal wetlands. In the first, the lagoon was exorheic, with prolonged flooding periods and a low residence time; in the second, it had a more endorheic character, with scarce water inputs and prolonged periods of confinement. Consequently, nitrogen inputs diminished and organic load and salinity increased as the internal loading and the accumulation effects became more relevant. These effects were actually caused by the drastic reduction in the freshwater inflow which prevented, in turn, the success of the restoration measures. The zooplankton community of the Ter Vell lagoon was not significantly altered by the hydrological change, at least in the short-term, and rotifers and cladocerans, mainly those species indicative of eutrophy, dominated the community.