scholarly journals A study on the salinization of coastal water of Sidi Boughaba Lake (Ramsar site 1980) in Morocco using the characteristic reports

2021 ◽  
Vol 234 ◽  
pp. 00016
Author(s):  
Mohamed Najy ◽  
Mohamed Lachhab ◽  
Hassan Ech-chafay ◽  
Fatima Zahra Talbi ◽  
Abderrahman Achhar ◽  
...  
Keyword(s):  
Saturation Index ◽  
Atlantic Coast ◽  
Chemical Study ◽  
Analysis Data ◽  
Major Elements ◽  
Ramsar Site ◽  
Piper Diagram ◽  
North West ◽  
Intense Evaporation ◽  
Marine Influence

The Lake Sidi Boughaba is a Ramsar site (1980) located on the Atlantic coast of north-west Morocco. It is oriented NNE - SSW and located in a secondary interdunal depression formed in a complex of the main wetlands of Morocco. The waters of this lake are deteriorating in quality, with increasing salinization. To identify the processes and chemical reactions that govern salinization, the main major elements as well as the pH, electrical conductivity and salinity were monitored during the winter and summer seasons of the years, 2016-2017 in 6 sites distributed throughout the year. The interpretation of the analysis data is carried out using the correlation of the major elements with the chlorides, the Piper diagram and the variation of the ionic ratios Na/Cl, SO4/Cl, Mg/Ca and the calculation of the saturation index. The saturation index is calculated by the software PHREEQC 2.8, used for modelling the state of saturation of minerals. The results of these analyzes revealed a variety of origins and processes of salinization of the waters. The hydro chemical study shows that the waters are brackish too salty; they are characterized by sodium chloride facies. This remarkable transition is mainly due to the intense evaporation that accentuates the mineralization. The values of the saturation index of the chemical minerals show the under saturation the anhydrite of the gypsum and the halite, on the other hand, the saturation or even supersaturation by the calcite and dolomite. The characteristic ratios of the chemical composition of waters show that salinity has two main origins: ion exchange between rock-water and marine influence by aerosols and sea spray.

Hydrochemistry and carbonate sediment characterisation of Bacalar Lagoon, Mexican Caribbean

2019 ◽  
Vol 70 (3) ◽  
pp. 382 ◽  
Author(s):  
Nidia I. Tobón Velázquez ◽  
Mario Rebolledo Vieyra ◽  
Adina Paytan ◽  
Kyle H. Broach ◽  
Laura M. Hernández Terrones
Keyword(s):  
Trace Elements ◽  
Water Column ◽  
Saturation Index ◽  
Major Elements ◽  
Anthropogenic Sources ◽  
Pollution Indices ◽  
Mexican Caribbean ◽  
High Concentrations ◽  
Geochemical Analyses ◽  
Changes Over Time

The aim of the study is to determine the distribution of trace and major elements in the water and in the sediments of the south part of the Bacalar Lagoon and to identify the sources of the trace elements and their changes over time. The western part of the lagoon water column is characterised by high concentrations of Ca2+, HCO3– and Sr2+, derived from groundwater input. In contrast, the eastern part of the lagoon is characterised by high concentrations of Mg2+, Na+ and Cl–. The lagoon is not affected by present-day seawater intrusion. Water column and sediment geochemical analyses performed in Bacalar Lagoon show clear spatial distribution of different parameters. The saturation index of the water column indicates three main groups: (1) a zone oversaturated with regard to aragonite, calcite and dolomite; (2) an undersaturated area where all three minerals are dissolving; and (3) an area with calcite equilibrium and undersaturation with regard to the other minerals. Herein we present the first measurements of trace element (Ba2+, Mn2+, K+, Ni2+, Zn2+) concentrations in carbonates obtained from sediments in Bacalar Lagoon. In order to evaluate whether the trace elements are derived from natural or anthropogenic sources, four pollution indices were calculated. The results confirmed that Bacalar Lagoon sediments are not contaminated with Ni2+, K+, Mn2+ and Ba2+, and that the Zn2+ seems to have a predominantly anthropogenic origin.

scholarly journals Contribution to the reproduction of Ruditapes decussatus in Oualidia lagoon and Dakhla bay (North West African Atlantic Coast)

2018 ◽  
Vol 5 ◽  
Author(s):  
Kaoutar HIMMI ◽  
Oum Keltoum BELHSEN ◽  
Mohamed ID HALLA ◽  
Yassine OUAGAJJOU ◽  
El Mustapha AIT CHATTOU ◽  
...  
Keyword(s):  
Atlantic Coast ◽  
West African ◽  
Ruditapes Decussatus ◽  
North West ◽  
Oualidia Lagoon ◽  
Dakhla Bay ◽  
African Atlantic

scholarly journals Ecological Niche Models Reveal Climate Change Effect on Biogeographical Regions: The Iberian Peninsula as a Case Study

Climate ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 42 ◽  
Author(s):  
Diana Sousa-Guedes ◽  
Salvador Arenas-Castro ◽  
Neftalí Sillero
Keyword(s):  
Iberian Peninsula ◽  
Environmental Conditions ◽  
Atlantic Coast ◽  
Group Method ◽  
Ecological Niche Models ◽  
North West ◽  
Pair Group ◽  
Climate Change Effect ◽  
Biogeographical Regions ◽  
Over Time

How species are distributed on Earth depends largely on climate factors. Whenever these environmental conditions change, species tend to shift their distributions to reach more favourable conditions. Distinct sets of species similarly distributed (i.e., chorotypes) occur in biogeographical regions with homogeneous environmental conditions. Here, we analysed whether biogeographical regions are unstable over time (from the past to the future). We modelled the realised niche of amphibians and reptiles in the Iberian Peninsula in the present, and several past and future climate scenarios. Then, we used Jaccard’s index and the unweighted pair group method (UPGMA) to define the biogeographical regions. Our results suggest that the biogeographical regions of Iberian amphibians and reptiles changed greatly over time, due to the climatic changes between periods. Biogeographical regions composed of species with Atlantic affinities changed particularly, overall gaining suitable areas in past colder periods and losing suitable areas in warmer periods. The areas of refugia for amphibians over time corresponded to the most humid regions (north-west of the peninsula), while the most important areas for reptiles occur in the south and on the Atlantic coast. The identification of biogeographical patterns considering past climate changes is essential to better apply conservation measures.

THE STAG OILFIELD

1996 ◽  
Vol 36 (1) ◽  
pp. 130 ◽  
Author(s):  
J. Crowley ◽  
E.S. Collins
Keyword(s):  
Water Saturation ◽  
Vertical Section ◽  
Far East ◽  
Total Porosity ◽  
Analysis Data ◽  
Effective Porosity ◽  
Seismic Survey ◽  
North West ◽  
The North ◽  
Southeastern Margin

The Stag Oilfield is located approximately 65 km northwest of Dampier and 25 km southwest of the Wandoo Oilfield near the southeastern margin of the Dampier Sub-basin, on the North West Shelf of Western Australia,.The Stag-1 discovery well was funded by Apache Energy Ltd (formerly Hadson Energy Ltd), Santos Ltd and Globex Far East in June 1993 under a farmin agreement with BHP Petroleum Pty Ltd, Norcen International Ltd and Phillips Australian Oil Co. The well intersected a gross oil column of 15.5 m within the Lower Cretaceous M. australis Sandstone. The oil column intersected at Stag-1 was thicker than the pre-drill mapped structural closure.A 3D seismic survey was acquired over the Stag area in November 1993 to define the size and extent of the accumulation. Following processing and interpretation of the data, an exploration and appraisal program was undertaken. The appraisal wells confirmed that the oil column exceeds mapped structural closure and that there is a stratigraphic component to the trapping mechanism. Two of the appraisal wells were tested; Stag-2 flowed 1050 BOPD from a 5 m vertical section and Stag-6 flowed at 6300 BOPD on pump from a 1030 m horizontal section.Evaluation of the well data indicates the M. australis Sandstone at the Stag Oilfield is genetically related to the reservoir section at the Wandoo Oilfield. The reservoir consists of bioturbated glauconitic subarkose and is interpreted to represent deposition that occurred on a quiescent broad marine shelf. Quantitative evaluation of the oil-in-place has been hampered by the effects of glauconite on wireline log, routine and special core analysis data. Petrophysical evaluation indicates that core porosities and water saturations derived from capillary pressure measurements more closely match total porosity and total water saturation than effective porosity and effective water saturation.A development plan is currently being prepared and additional appraisal drilling in the field is expected.

A new species of the genus Celleporella (Bryozoa: Cheilostomatida) from the European Atlantic Coast

1999 ◽  
Vol 79 (1) ◽  
pp. 51-55 ◽  
Author(s):  
J. César-Aldariz ◽  
E. Fernández-Pulpeiro ◽  
O. Reverter-Gil
Keyword(s):  
New Species ◽  
Atlantic Coast ◽  
North West ◽  
A New Species

A new species of the genus Celleporella (Celleporella galaica sp. nov.) is described from material collected in Galicia (north-west Spain).

Isotopic and geochemical methods for studying water–rock interaction and recharge mode: application to the Cenomanian–Turonian and Plio-Quaternary aquifers of Essaouira Basin, Morocco

2018 ◽  
Vol 69 (8) ◽  
pp. 1290 ◽  
Author(s):  
Mohammed Bahir ◽  
Salah Ouhamdouch ◽  
Paulà M. Carreira
Keyword(s):  
Meteoric Water ◽  
Major Ions ◽  
Major Elements ◽  
Exchange Reactions ◽  
Rock Interaction ◽  
Water Line ◽  
North West ◽  
Meteoric Water Line ◽  
Essaouira Basin ◽  
Quaternary Aquifers

Study of the Cenomanian–Turonian and Plio–Quaternary aquifers of Essaouira basin (Western Morocco), based on the interpretation of geochemical (major elements) and isotopic (18O, 2H, 13C and 14C) data, has aided the understanding of the hydrodynamics of these aquifers, which is greatly affected by tectonics. Hydrochemical characteristics based on the bivariate diagrams of major ions (Cl–, SO42–, NO3–, HCO3–, Na+, Mg2+, K+ and Ca2+) and electrical conductivity and mineral saturation indices indicate that the origins of groundwater mineralisation are the result of: (1) evaporite dissolution; (2) cation exchange reactions; (3) and evaporation processes. Radiogenic isotopes (3H and 14C) have highlighted the presence of significant recent recharge in the eastern part of the basin, with groundwater moving according to the general flow path (south-east to north-west). Stable isotope data from the Essaouira basin plot along the Global Meteoric Water Line and below the Local Meteoric Water Line. This suggests that groundwater has been recharged under several different climate regimes.

scholarly journals Trends in strandings and by-catch of marine mammals in north-west Spain during the 1990s

2002 ◽  
Vol 82 (3) ◽  
pp. 513-521 ◽  
Author(s):  
A. López ◽  
M.B. Santos ◽  
G.J. Pierce ◽  
A.F. González ◽  
X. Valeiras ◽  
...  
Keyword(s):  
Marine Mammals ◽  
Atlantic Coast ◽  
Western Coast ◽  
Common Dolphin ◽  
North West ◽  
The North ◽  
By Catch ◽  
Average Size ◽  
Autumn And Winter ◽  
Common Dolphins

Strandings of marine mammals on the north-western Spanish coast (Galicia) have been systematically recorded since 1990. A total of 1433 marine mammals belonging to 15 species was recorded from 1990 to 1999. The most frequently recorded species stranded were common dolphin (47%), bottlenose dolphin (11%) and harbour porpoise (7%). The number of strandings recorded increased annually over the study period, probably reflecting an increased observer effort. During 1996–1999, an average of 1·65 animals were stranded annually for each 10 km of coastline, the highest density of strandings recorded on the Atlantic coast of the Iberian Peninsula. More than 80% of the strandings were located on the western coast of Galicia, mainly in autumn and winter. During the study period, 42 proven incidental catches were recorded, although signs of by-catch were seen in a further 198 animals. The average size of stranded common dolphins and the proportion of males both increased towards the end of the calendar year.

scholarly journals S.O.S. Souss: argan forest destruction in Morocco

Oryx ◽  
1989 ◽  
Vol 23 (2) ◽  
pp. 87-93 ◽  
Author(s):  
Jesú Mellado
Keyword(s):  
West Africa ◽  
Forest Ecosystem ◽  
Atlantic Coast ◽  
Edible Oil ◽  
Effective Protection ◽  
North West ◽  
Sustainable Exploitation ◽  
Argan Tree

The Souss Valley in Morocco still has remnants of forest dominated by the argan tree, which is endemic to the Atlantic coast of north-west Africa. The tree is valued for its edible oil and its timber and the argan forest ecosystem is rich in species. The forest has been exploited sustainably by man tor thousands of years, but modern developments have destroyed or damaged much of it, especiallyin the lowlands. The author, who worked in the region for three years, is alarmed at the rapidly increasing destruction. He makes a plea for effective protection of the remaining argan torest and for a plan for its sustainable exploitation.

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