Impact of shorebird predation on intertidal macroinvertebrates in a key North African Atlantic wintering site: an experimental approach

Shorebirds, as migratory aquatic birds and top predators in intertidal ecosystems, can be affected by global environmental changes and escalations in local impacts on coastal lagoons and estuarine trophic networks. Many shorebirds winter in North African Atlantic coastal sites, most likely because these locations provide constant and reliable food supplies with less energy costs in comparison with the wintering sites of northern Europe. Although more information is available for other important southern coastal sites (e.g. Saharan Atlantic coastal desert and Guinean mangroves coast), very little information is available for the North African Atlantic coast. Here, we focus on the impact of shorebird predation on benthic macroinvertebrates in a major wintering site in this area—Sidi Moussa coastal lagoon, Morocco—using an exclosure experiment. For most of the macroinvertebrate species there was no significant effect of the exclusion of shorebird predation. Overall, our results do not show evidence that predation by shorebirds influenced the overall standing biomass of the benthic community. This may indicate that the benthic productivity is high enough to provide constant and reliable food supplies for non-breeding shorebirds.     

Rare Earth Elements Around the Barakah Nuclear Power Plant,UAE

Natural Resources Research - Rare earth element (REE) contamination has major consequences for the environment and humans. Some forms of REEs have more serious environmental impacts than others. It...     

Palynological,palynofacies, paleoenvironmental and organic geochemical studies on the Upper Cretaceous succession of the GPTSW-7 well,North Western Desert,Egypt

The present study of the Abu Roash and Bahariya formations in well GPTSW-7 refines our understanding of the subsurface Cretaceous of the north Western Desert of Egypt. Our investigations are based on the palynological analyses of 71 cuttings samples, of which 24 have also been analyzed for geochemistry, in addition to 3 sidewall cores analyzed for vitrinite reflectance (R_o).     

Supported TiO2 on Kaolin,Cordierite, and Calcite for Photocatalytic Removal of Dyes from Wastewater

Kaolin, cordierite, and calcite are investigated as supports for TiO₂. The prepared TiO₂/support samples are examined for the removal of organic dyes from wastewater. The samples are preliminarily investigated to identify the optimal loaded system using synthetic wastewater containing methylene blue (MB). Data indicate that the investigated support significantly affects the photocatalytic activity of the supported TiO₂. Low photocatalytic activity toward MB degradation is observed upon using TiO₂/calcite when compared to the unsupported TiO₂. Interaction between calcite and titania species probably occurrs to produce the less photoactive CaTiO₃ amorphous species. Anatase TiO₂ is obtained upon using kaolin and cordierite as supports. The low photocatalytic performance of the TiO₂/kaolin sample is also observed. A high concentration of MB on TiO₂/kaolin surfaces blocks the photoactive sites. TiO₂/cordierite shows the highest photocatalytic activity compared to the unsupported TiO₂ as well as the other TiO₂/support samples. Rigid cordierite particles suppress the agglomeration of TiO₂ particles during the preparation, leading to a high exposed surface of TiO₂ towards light illumination. TiO₂/cordierite is investigated for the removal of organic dye from real wastewater collected from a textile dyeing factory. Color removal of up to 46% is achieved upon UV irradiation.     

Integrated coastal zone management programme northwest African region case

The development of industrial and tourism activities as well as the increase in the urban population in the northwest African region has generally been highly concentrated in the coastal zone. Due to high rates of population growth, urbanisation is likely to increase dramatically in the coming future. This paper presents a physical and socio-economic environmental analysis of the region and highlights the few efforts that have called for the development of co-ordinated strategies in view of integrated coastal zone management. Experience in the implementation of methodologies for adopting integrated coastal zone management strategies in these countries is discussed.     

Two orogenies in the Meatiq area of the Central Eastern Desert,Egypt

The Pan-African basement exposed in the Meatiq area west of Quseir, Egypt, consists of an infracrustal basement overthrusted by a supracrustal cover. The infracrustal rocks were developed as a result of an old orogeny referred to as the Meatiqian orogeny where granite—gneiss, migmatitic gneisses and migmatized amphibolites were formed. The granite—gneiss represents a deformed granite pluton emplaced at 626±2 Ma, whereas the migmatitic gneisses and amphibolites are of mixed igneous and sedimentary parentage. In view of the data so far available, the nature of the Meatiqian orogeny could not be deciphered. In spite of the young isotopic ages, it is suggested that at least the metasedimentary gneisses represent older rocks in the stratigraphic sequence of the infracrustal basement.The supracrustal cover represents a part of an extensive ophiolitic mélange obducted onto the infracrustal basement during the next orogeny (Abu Ziran orogeny) which culminated at 613±2 Ma. An active continental margin-type regime can adequately explain the evolution of such a supracrustal cover. During obduction, the ophiolitic mélange and the upper 2 km thick part of the infracrustal basement were intensely deformed and metamorphosed under PT conditions of the greenschist—epidote amphibolite facies. The deformed infracrustal basement was converted into mylonitic—blastomylonitic rocks and schists composing five thrust sheets, and subsequently intruded by synkinematic granitoid sheets. Later, both the infracrustal basement and the overlying supracrustal cover were isostatically uplifted, subjected to complex shallow folding giving rise to the major Meatiq domal structure, and were intruded by a postkinematic adamellite pluton at 579±6 Ma.     

Padé approximants for radiative transfer in inhomogeneous medium

The Padé approximants is used to estimate the albedo for an inhomogeneous semi-infinite medium. The single-scattering albedo is assumed to fall off exponentially with optical depth.     

Two forsterite-bearing FUN inclusions in the Allende meteorite

We have discovered two FUN inclusions, CG-14 and TE, among a group of five forsterite-rich inclusions in Allende, two of which are described for the first time herein. All five consist of euhedral forsterite and spinel crystals poikilitically enclosed by fassaite. Forsterite and spinel are usually segregated from one another, sometimes into a spinel-rich mantle and a forsterite-rich core. Some inclusions contain vesicles, indicating that they were once molten. The crystallization sequence inferred from textures is: spinel, forsterite, fassaite and, finally, Mg-rich melilite. One concentrically-zoned inclusion contains melilite in its mantle whose composition lies on the opposite side of the liquidus minimum in the melilite binary from that in its core. This suggests that segregation of forsterite from spinel in all of these inclusions could be due to volatilization of MgO and SiO₂ relative to Al₂O₃ and CaO from the outsides of droplets. CG-14 is relatively uniformly enriched in refractory elements relative to Cl chondrites by a factor similar to that for Ca-, Al-rich coarse-grained inclusions except for Ca, Al and Hf which are unusually low. No Ce anomaly such as found in FUN inclusions Cl and HAL is present in CG-14. Whole-rock samples of CG-14 and TE are more strongly mass-fractionated in oxygen relative to “normal” Allende inclusions than the FUN inclusion EK 1-4-1 and less so than Cl. Relative to bulk Allende, both inclusions have strongly massfractionated magnesium and silicon and ²⁵Mg excesses or deficits of ²⁴Mg or ²⁶Mg. CG-14 has a ²⁹Si excess or a deficit of ²⁸Si or ³⁰Si. Volatilization loss cannot be responsible for the magnesium and silicon isotope fractionations, as this would require prohibitively large mass loss from these magnesium-rich inclusions. The remarkable similarity in textures between FUN and non-FUN inclusions implies similar thermal histories, arguing against different rates of evaporative loss of major elements. Sputtering alone may be insufficient to account for the magnitude and direction of oxygen isotope fractionation in FUN inclusions.