Journal articles: 'Algerian basin'

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Haddad, Benalia, Alessandro Silvestre Gristina, Francesco Mercati, Abd Elkader Saadi, Nassima Aiter, Adriana Martorana, Abdoallah Sharaf, and Francesco Carimi. "Molecular Analysis of the Official Algerian Olive Collection Highlighted a Hotspot of Biodiversity in the Central Mediterranean Basin." Genes 11, no. 3 (March 13, 2020): 303. http://dx.doi.org/10.3390/genes11030303.

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Genetic diversity and population structure studies of local olive germplasm are important to safeguard biodiversity, for genetic resources management and to improve the knowledge on the distribution and evolution patterns of this species. In the present study Algerian olive germplasm was characterized using 16 nuclear (nuSSR) and six chloroplast (cpSSR) microsatellites. Algerian varieties, collected from the National Olive Germplasm Repository (ITAFV), 10 of which had never been genotyped before, were analyzed. Our results highlighted the presence of an exclusive genetic core represented by 13 cultivars located in a mountainous area in the North-East of Algeria, named Little Kabylie. Comparison with published datasets, representative of the Mediterranean genetic background, revealed that the most Algerian varieties showed affinity with Central and Eastern Mediterranean cultivars. Interestingly, cpSSR phylogenetic analysis supported results from nuSSRs, highlighting similarities between Algerian germplasm and wild olives from Greece, Italy, Spain and Morocco. This study sheds light on the genetic relationship of Algerian and Mediterranean olive germplasm suggesting possible events of secondary domestication and/or crossing and hybridization across the Mediterranean area. Our findings revealed a distinctive genetic background for cultivars from Little Kabylie and support the increasing awareness that North Africa represents a hotspot of diversity for crop varieties and crop wild relative species.

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GRIMES, SAMIR, MOULOUD BENABDI, NADHERA BABALI, WAHID REFES, NAWAL BOUDJELLAL-KAIDI, and HALIMA SERIDI. "Biodiversity changes along the Algerian coast (Southwest Mediterranean basin): from 1834 to 2017: A first assessment of introduced species." Mediterranean Marine Science 19, no. 1 (May 23, 2018): 156. http://dx.doi.org/10.12681/mms.13824.

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“Introduced” species of the Algerian coast remains the most undocumented issue in the Mediterranean Sea. Only few studies were dedicated to Introduced species due to the lack of taxonomists. In-depth research on Introduced species along the Algerian coast should provide new data that could explain the spreading mechanisms in the southwestern part of the Mediterranean basin particularly near the Alboran Sea. Introduced species among other related research; of which the outcome is expected in the next few years, is in progress in the southwest Mediterranean basin. The aim of this work is to provide an inventory of available data pertaining to marine species “introduced” in Algerian waters, whether these species were introduced intentionally or accidentally. This large number of Introduced species records covers the period from 1834 to December 2017. Seventy “Introduced” species have been recorded along the Algerian coast, composed by 55.7% true aliens25.7 % range expanding species, 15.7% cryptogenic species and 2,9% vagrant species, with a clear domination of fish (38.57%) and macroalgae (30%). Approximately 348 introduction events have been reported; 64,9 % of them belong to macroalgae and one sighting out of two is done in the central region. The distribution and the status of introduced species in Algeria were evaluated. In total, 20% of the Introduced species can be considered as established along the Algerian coast, in particular the macrophyta, Codium fragile and Ulva lactuca as well as the cryptogenic species, Oculina patagonica, while Asparagopsis armata, A. taxiformis and Caulerpa cylindracea are considered as invasive.

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Mallil, Katia, Pierre Testor, Anthony Bosse, Félix Margirier, Loic Houpert, Hervé Le Goff, Laurent Mortier, and Ferial Louanchi. "The Levantine Intermediate Water in the western Mediterranean and its interactions with the Algerian Gyres: insights from 60 years of observation." Ocean Science 18, no. 4 (July 5, 2022): 937–52. http://dx.doi.org/10.5194/os-18-937-2022.

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Abstract. The presence of two large-scale cyclonic gyres in the Algerian Basin influences the general and eddy circulation, but their effects on water mass transfer remain poorly characterized. Our study has confirmed the presence of these gyres using the first direct current measurements of the whole water column collected during the SOMBA-GE2014 cruise, specifically designed to investigate these gyres. Using cruise sections and a climatology from 60 years of in situ measurements, we have also shown the effect of these gyres on the distribution at intermediate depth of Levantine Intermediate Water (LIW) with warmer (∼ 0.15 ∘C) and saltier (∼ 0.02) characteristics in the Algerian Basin than in the Provençal Basin. The Algerian Gyres, combined with the effect of anticyclonic Algerian Eddies, also impact horizontal density gradients with sinking of the isopycnals at the gyres' centers. Temporal cross-correlation of LIW potential temperature referenced to a signal observed southwest of Sardinia reveals a timescale of transit of 4 months to get to the center of the Algerian Basin. The LIW potential temperature and salinity trends, on average in the basin interior, are estimated to be +0.0022 ± 0.0002 ∘Cyr-1 and +0.0022 ± 0.0001 yr−1, respectively, over the 1968–2017 period and accelerating to +0.048 ± 0.003 ∘Cyr-1 and +0.0076 ± 0.0009 yr−1 over the 2013–2017 period.

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Atrouz, Kamel, Ratiba Bousba, Francesco Paolo Marra, Annalisa Marchese, Francesca Luisa Conforti, Benedetta Perrone, Hamza Harkat, Amelia Salimonti, and Samanta Zelasco. "Algerian Olive Germplasm and Its Relationships with the Central-Western Mediterranean Varieties Contributes to Clarify Cultivated Olive Diversification." Plants 10, no. 4 (April 1, 2021): 678. http://dx.doi.org/10.3390/plants10040678.

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Olive tree with its main final product, olive oil, is an important element of Mediterranean history, considered the emblematic fruit of a civilization. Despite its wide diffusion and economic and cultural importance, its evolutionary and phylogenetic history is still difficult to clarify. As part of the Mediterranean basin, Algeria was indicated as a secondary diversification center. However, genetic characterization studies from Maghreb area, are currently underrepresented. In this context, we characterized 119 endemic Algerian accessions by using 12 microsatellite markers with the main goal to evaluate the genetic diversity and population structure. In order to provide new insights about the history of olive diversification events in the Central-Western Mediterranean basin, we included and analyzed a sample of 103 Italian accessions from Sicily and, a set of molecular profiles of cultivars from the Central-Western Mediterranean area. The phylogenetic investigation let us to evaluate genetic relationships among Central-Mediterranean basin olive germplasm, highlight new synonymy cases to support the importance of vegetative propagation in the cultivated olive diffusion and consolidate the hypothesis of more recent admixture events occurrence. This work provided new information about Algerian germplasm biodiversity and contributed to clarify olive diversification process.

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Perkins, Henry, and Pavel Pistek. "Circulation in the Algerian Basin during June 1986." Journal of Geophysical Research 95, no. C2 (1990): 1577. http://dx.doi.org/10.1029/jc095ic02p01577.

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Cotroneo, Yuri, Giuseppe Aulicino, Simon Ruiz, Antonio Sánchez Román, Marc Torner Tomàs, Ananda Pascual, Giannetta Fusco, Emma Heslop, Joaquín Tintoré, and Giorgio Budillon. "Glider data collected during the Algerian Basin Circulation Unmanned Survey." Earth System Science Data 11, no. 1 (January 28, 2019): 147–61. http://dx.doi.org/10.5194/essd-11-147-2019.

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Abstract. We present data collected in the framework of the Algerian BAsin Circulation Unmanned Survey (ABACUS) project. The main objective of ABACUS is the monitoring of the basin circulation and of the surface and intermediate water masses' physical and biological properties in a key region of the Mediterranean Sea circulation. Data presented here have been collected through deep glider cruises in the Western Mediterranean Sea during the autumns of 2014, 2015 and 2016; activities at sea are expected to be repeated during the coming years, so that the dataset will be extended. Glider missions were conducted in the Algerian Basin, between the island of Mallorca and the Algerian coast. Across the three glider missions, eight repeated transects were completed which enabled us to investigate the basin-scale circulation and the presence of mesoscale structures, utilising both the adaptive sampling capabilities of the gliders and the higher resolution of the data. After collection, all data passed a quality control procedure and were then made available through an unrestricted repository host by the SOCIB Data Centre at https://doi.org/10.25704/b200-3vf5. The actual dataset spans three autumn seasons, providing an important contribution to the data collection in the chronically undersampled Algerian Basin. Temperature and salinity data collected in the first 975 m of the water column allowed us to identify the main water masses and describe their characteristics, improving the understanding of the dynamics of the region. On the timescale of the project, data show a large variability in the surface layer and reduced variability in the intermediate and deep layers. Our measurements have been successfully compared to data previously collected in the area from 1909 to 2011. Results showed similar overall distribution, ranges and variability to the historical data, with no outliers in the surface or deep layers.

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Pessini, Federica, Antonio Olita, Yuri Cotroneo, and Angelo Perilli. "Mesoscale eddies in the Algerian Basin: do they differ as a function of their formation site?" Ocean Science 14, no. 4 (July 20, 2018): 669–88. http://dx.doi.org/10.5194/os-14-669-2018.

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Abstract. The circulation of the western Mediterranean Sea (WMED) is dominated by highly variable and heterogeneous mesoscale circulation that is strongly driven by the formation and propagation of eddies (cyclonic and anticyclonic) mainly acting in the Algerian Basin. In order to investigate the spatial and temporal distribution of eddy generation and their respective paths in the Algerian Basin, the most energetic WMED portion, we use an automated detection and tracking hybrid method applied to 24 years of sea level anomaly (SLA) data. The algorithm is based on the computation of the Okubo–Weiss parameter in SLA closed loops and has been modified in order to fill the gaps in single eddy tracks. In this work we analysed both cyclonic and anticyclonic structures, but the conclusions will be focused mainly on anticyclones with a lifespan longer than 3 months, as they are characterized by higher kinetic energy, thereby potentially contributing to a large extent to the mesoscale characterization of the basin. In particular, we find that anticyclonic short-life eddies mostly occur in the northern portion of the domain, north of 39∘ N along the North Balearic Front (NBF). Such short-life eddies, labelled frontal eddies (FEs), are characterized by low translational velocity and a highly variable direction of propagation. We found a weak seasonality in their formation, with maxima in fall and winter. By contrast, anticyclonic longer-life eddies tend to arise in the southern part of the basin along the Algerian Current, with a clear maximum in spring. All the structures (both cyclonic and anticyclonic) originating along the Algerian Current are known as Algerian eddies (AEs). According to previous studies, we observe that these anticyclonic eddies mainly form east of 6.5∘ E and move eastward along the African coast to the Sardinia Channel, where they detach from the coast, continuing offshore and following the cyclonic intermediate circulation. We detect a region between 4.5 and 6.5∘ E where such eddies tend to converge and terminate their life. Finally, the analysis suggests that eddies formed in the northern and in the southern part of the Algerian Basin present some physical differences such as lifetime, kinetic energy and vorticity. Furthermore, the connection between the two parts in terms of eddy tracks is limited to a very small number of southbound (FEs) or northbound (AEs) structures crossing 39∘ N.

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Alioua, Zakia, Soumia Amira, Ghollame Ellah Yacine Khames, Ulla Fernandez-Arcaya, Beatriz Guijarro, Francesc Ordines, Enric Massutí, and Fatiha Zerouali-Khodja. "Population structure, reproduction and exploitation of the greater forkbeard Phycis blennoides (Brünnich, 1768) from the Algerian basin." Aquatic Living Resources 33 (2020): 20. http://dx.doi.org/10.1051/alr/2020021.

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The objective of this study was to determine the population distribution and some biological aspects for fish stock assessment of the greater forkbeard Phycis blennoides along the Algerian basin. The distribution of P. blennoides (3418 individuals) was studied using data collected between 170–779 m depth during two bottom trawl surveys developed on 2003 and 2004. Additionally, some biological parameters were obtained from 1050 individuals sampled from commercial fisheries in Algerian ports (i.e. Annaba, Azeffoun, Dellys, Cap Djinet, Zemmouri, Bouharoun, Algiers, La Madrague, Cherchell, Tenes and Mostaganem) during the period 2013–2017. P. blennoides sampled from bottom trawl surveys showed a depth related distribution with the largest individuals being found at 600–800 m depth and the smallest at shallower depths. Density and biomass varied with depth and density also with longitude, while biomass showed no pattern with longitude. Recruitment was recorded in the eastern sector of Algeria during winter, for individuals sampled by bottom trawl surveys. Young P. blennoides entered commercial fisheries in summer, with an overall sex ratio skewed towards males (1F:2.18M). The size at first maturity (L 50) was 24.30 cm and 30.39 cm for males and females, respectively. The age at 50% maturity was 2–3 years for specimens collected by a bottom trawl survey in 2003 and commercial fisheries, but 3–4 years for the bottom trawl survey in 2004.

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Mauffret, A., D. Frizon de Lamotte, S. Lallemant, C. Gorini, and A. Maillard. "E-W opening of the Algerian Basin (Western Mediterranean)." Terra Nova 16, no. 5 (October 2004): 257–64. http://dx.doi.org/10.1111/j.1365-3121.2004.00559.x.

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Hamida, Chafia, and M. Hichem Kara. "First documented record of the Atlantic blue crab Callinectes sapidus Rathbun, 1896 from the southwestern Mediterranean coasts." Crustaceana 94, no. 3 (March 2, 2021): 283–92. http://dx.doi.org/10.1163/15685403-bja10051.

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Abstract A previous record of the alien crab Callinectes sapidus from the Algerian coasts was based on a photograph provided by a fisherman showing the dorsal side of a single individual. In this contribution, we confirm this presence in the mouth of the Mafragh Estuary in eastern Algeria, where four individuals of this species were found on 19 November 2019. The specimens examined are one female (60 mm CL, 125.9 g) and three males (60-66 mm CL, 120.4-176.8 g). This discovery confirms the presence of this species in the southwestern Mediterranean Basin where it could become invasive in suitable habitats.

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Islem Boukara, Issam Habbouche, and Bachir Nabti. "Essential oil-based phytochemical identification of the Algerian north-central species of Thymus algeriensis." GSC Biological and Pharmaceutical Sciences 23, no. 3 (June 30, 2023): 075–82. http://dx.doi.org/10.30574/gscbps.2023.23.3.0206.

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Thymus algeriensis is a Lamiales member especially widespread through the Mediterranean basin, including the northern African region. Algeria counts numerous variants of the species, thriving in disparate locations and climates. The usage of aromatic species’ essential oils for the variants identification and the applications adaptation is a practice known as chemotype determination, objective of this study, with the Algerian north-central Thymus algeriensis as target. Gas chromatography coupled to mass spectrometry was used to analyze the Clevenger apparatus-extracted essential oil, and leaves staining was performed for the morphological identification. The species chemotype was Linalool dominant, highlighting the difference to adjacent territories growing variants reported in the literature.

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Aulicino, Giuseppe, Yuri Cotroneo, Estrella Olmedo, Cinzia Cesarano, Giannetta Fusco, and Giorgio Budillon. "In Situ and Satellite Sea Surface Salinity in the Algerian Basin Observed through ABACUS Glider Measurements and BEC SMOS Regional Products." Remote Sensing 11, no. 11 (June 6, 2019): 1361. http://dx.doi.org/10.3390/rs11111361.

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The Algerian Basin is a key area for the general circulation in the western Mediterranean Sea. The basin has an intense inflow/outflow regime with complex circulation patterns, involving both fresh Atlantic water and more saline Mediterranean water. Several studies have demonstrated the advantages of the combined use of autonomous underwater vehicles, such as gliders, with remotely sensed products (e.g., altimetry, MUR SST) to observe meso- and submesoscale structures and their properties. An important contribution could come from a new generation of enhanced satellite sea surface salinity (SSS) products, e.g., those provided by the Soil Moisture and Ocean Salinity (SMOS) mission. In this paper, we assess the advantages of using Barcelona Expert Center (BEC) SMOS SSS products, obtained through a combination of debiased non-Bayesian retrieval, DINEOF (data interpolating empirical orthogonal functions) and multifractal fusion with high resolution sea surface temperature (OSTIA SST) maps. Such an aim was reached by comparing SMOS Level-3 (L3) and Level-4 (L4) SSS products with in situ high resolution glider measurements collected in the framework of the Algerian Basin Circulation Unmanned Survey (ABACUS) observational program conducted in the Algerian Basin during falls 2014–2016. Results show that different levels of confidence between in situ and satellite measurements can be achieved according to the spatial scales of variability. Although SMOS values slightly underestimate in situ observations (mean difference is −0.14 (−0.11)), with a standard deviation of 0.25 (0.26) for L3 (L4) products), at basin scale, the enhanced SMOS products well represent the salinity patterns described by the ABACUS data.

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Driussi, Olivier, Anne Briais, and Agnès Maillard. "Evidence for transform motion along the South Balearic margin and implications for the kinematics of opening of the Algerian basin." Bulletin de la Société Géologique de France 186, no. 4-5 (July 1, 2015): 353–70. http://dx.doi.org/10.2113/gssgfbull.186.4-5.353.

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Abstract Two major types of kinematic models have been proposed to explain the opening of the western Mediterranean basins (Liguro-Provençal and Algerian basins, and Valencia trough). In one type of models, all continental blocks bounding the basins drift to the southeast, driven by the rollback of the Tethys subduction slab. In the other type of models, the Alboran domain drifts to the southwest, implying a westward rollback of the broken subducting slab and a NE-SW opening of the Algerian basin. In most models, however, the structure of the Balearic promontory was not taken into account, despite its key location at the boundary of the three major basins. We used the interpretation of a large seismic database coupled to gravity and magnetic anomaly analyses to characterize the nature and structure of the South Balearic margin. The constraints brought by the new analyses allow us to suggest a new scenario for the opening of the Algerian basin. Seismic profiles show that the South Balearic margin is composed of four segments with different morphologies and crustal structures. Two segments, the Mazarron and the Emile Baudot escarpments, are characterized by steep scarps and sharp crustal thinning. Two other segments, the South Ibiza and South Menorca margins, have a smoother bathymetry and crustal thinning. We interpret the former in terms of transform margins, and the latter as divergent margins. The distribution of faults on the passive margin segments suggests that they have recorded at least two phases of deformation. A first phase of opening, probably in a NW-SE direction, affected the south Balearic margin, and possibly created some oceanic floor. The existence of the transform margin segments and the prominent NW-SE orientation of the magnetic lineations in the eastern Algerian basin suggest that most of this basin opened in a NE-SW direction, in different oceanic corridors. The two eastern corridors formed by the southwestward drift of the Kabylies. The western corridor, bounded by the transform segments of the South Balearic margin and the Algerian margin, results from the southwestward drift of the Alboran domain, as suggested by previous studies.

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Mihoubi, M. K., R. Belkessa, and M. A. Latreche. "Study of the Vulnerability of Coastal Areas of the Algerian Basin with the GIS." International Journal of Environmental Science and Development 5, no. 6 (2014): 522–26. http://dx.doi.org/10.7763/ijesd.2014.v5.538.

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Agulló, Jonás C., Ana Juan, Manuel B. Crespo, María Ángeles Alonso, and Alejandro Terrones. "An updated report on the distribution and conservation status of the endangered Cat’s Head Rockrose Helianthemum caput-felis (Magnoliopsida: Violales: Cistaceae) in Algeria." Journal of Threatened Taxa 9, no. 3 (March 26, 2017): 9885. http://dx.doi.org/10.11609/jott.2592.9.3.9885-9891.

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Helianthemum caput-felis is an Endangered plant species growing in the western Mediterranean basin. Its distribution is well known to the European and Moroccan regional populations, but no data from its distribution in Algeria have been reported since the middle 20th century. In this study, we provide an up-to-date report on the distribution of the species in Algeria. Fieldwork surveys in the classical locations were unsuccessful in finding the species, probably due to human habitat disturbances; however, a relict location was found in Ain-el-Kerma, near one of the historical known locations. As there is reduced distribution we point out the main causes that threaten the habitat of H. caput-felis according to IUCN threats classification scheme and we also propose to label it in the Algerian Red List as regionally Critically Endangered (CRreg B1ab(i,ii,iii, v)+2ab(i,ii,iii,v); C2a(i,ii); D).

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Taillandier, Vincent, Louis Prieur, Fabrizio D'Ortenzio, Maurizio Ribera d'Alcalà, and Elvira Pulido-Villena. "Profiling float observation of thermohaline staircases in the western Mediterranean Sea and impact on nutrient fluxes." Biogeosciences 17, no. 13 (July 2, 2020): 3343–66. http://dx.doi.org/10.5194/bg-17-3343-2020.

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Abstract. In the western Mediterranean Sea, Levantine intermediate waters (LIW), which circulate below the surface productive zone, progressively accumulate nutrients along their pathway from the Tyrrhenian Sea to the Algerian Basin. This study addresses the role played by diffusion in the nutrient enrichment of the LIW, a process particularly relevant inside step-layer structures extending down to deep waters – structures known as thermohaline staircases. Profiling float observations confirmed that staircases develop over epicentral regions confined in large-scale circulation features and maintained by saltier LIW inflows on the periphery. Thanks to a high profiling frequency over the 4-year period 2013–2017, float observations reveal the temporal continuity of the layering patterns encountered during the cruise PEACETIME and document the evolution of layer properties by about +0.06 ∘C in temperature and +0.02 in salinity. In the Algerian Basin, the analysis of in situ lateral density ratios untangled double-diffusive convection as a driver of thermohaline changes inside epicentral regions and isopycnal diffusion as a driver of heat and salt exchanges with the surrounding sources. In the Tyrrhenian Sea, the nitrate flux across thermohaline staircases, as opposed to the downward salt flux, contributes up to 25 % of the total nitrate pool supplied to the LIW by vertical transfer. Overall, however, the nutrient enrichment of the LIW is driven mostly by other sources, coastal or atmospheric, as well as by inputs advected from the Algerian Basin.

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Millot, Claude. "The circulation of the Levantine Intermediate Water in the Algerian Basin." Journal of Geophysical Research 92, no. C8 (1987): 8265. http://dx.doi.org/10.1029/jc092ic08p08265.

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Ruiz, S., J. Font, M. Emelianov, J. Isern-Fontanet, C. Millot, J. Salas, and I. Taupier-Letage. "Deep structure of an open sea eddy in the Algerian Basin." Journal of Marine Systems 33-34 (June 2002): 179–95. http://dx.doi.org/10.1016/s0924-7963(02)00058-1.

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di Rienzo, Valentina, Sara Sion, Francesca Taranto, Nunzio D’Agostino, Cinzia Montemurro, Valentina Fanelli, Wilma Sabetta, et al. "Genetic flow among olive populations within the Mediterranean basin." PeerJ 6 (July 11, 2018): e5260. http://dx.doi.org/10.7717/peerj.5260.

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Background The olive tree is a typical crop of the Mediterranean basin where it shows a wide diversity, accounting for more than 2,600 cultivars. The ability to discriminate olive cultivars and determine their genetic variability is pivotal for an optimal exploitation of olive genetic resources. Methods We investigated the genetic diversity within 128 olive accessions belonging to four countries in the Mediterranean Basin (Italy, Algeria, Syria, and Malta), with the purpose of better understanding the origin and spread of the olive genotypes across Mediterranean Basin countries. Eleven highly polymorphic simple sequence repeat (SSR) markers were used and proved to be very informative, producing a total of 179 alleles. Results Cluster analysis distinguished three main groups according to their geographical origin, with the current sample of Maltese accessions included in the Italian group. Phylogenetic analysis further differentiated Italian and Maltese olive accessions, clarifying the intermediate position of Maltese accessions along the x/y-axes of principal coordinate analysis (PCoA). Model-based and neighbor clustering, PCoA, and migration analysis suggested the existence of two different gene pools (Algerian and Syrian) and that the genetic exchange occurred between the Syrian, Italian and Maltese populations. Discussion The close relationship between Syrian and Italian and Maltese olives was consistent with the historical domestication and migration of olive tree from the North Levant to eastern Mediterranean basin. This study lays the foundations for a better understanding of olive genetic diversity in the Mediterranean basin and represents a step toward an optimal conservation and exploitation of olive genetic resources.

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Ferhani, Khadra, Djamel Bekrattou, and Salim Mouffok. "Body morphometric and otolith shape analyses of anchovy (Engraulis encrasicolus (Linnaeus, 1758)) in the Algerian basin." Acta Adriatica 62, no. 2 (December 22, 2021): 159–70. http://dx.doi.org/10.32582/aa.62.2.4.

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Body morphometric characteristics and otolith shape described by elliptic Fourier descriptors analyses were carried out on European anchovy (Engraulis encrasicolus) samples collected from six locations in Algerian waters during the acoustic survey ALPEL2018 (south-western Mediterranean Sea, GFCM-GSA04). The discriminant analysis was applied over twelve morphometric body distances and 31 normalized elliptic Fourier descriptors. It highlighted significant difference between areas but with high overlapping. No significant difference was detected between males and females, or right and left otoliths. Hierarchical clustering analysis conducted on the mean form of body and otolith shape showed a clear geographical cline. The results indicate that the geographical trend is present with a high level of overlapping between the near areas, suggesting that European anchovies in Algerian waters are not completely isolated.

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Yeakley, Julia A., Abdul Shakoor, and William Johnson. "Influence of Salt Tectonics On Fault Displacements and Submarine Slope Failures from Algeria To Sardinia." Environmental and Engineering Geoscience 25, no. 4 (November 8, 2019): 318–30. http://dx.doi.org/10.2113/eeg-2248.

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ABSTRACT We used previously obtained marine geophysical and geotechnical data for the proposed Galsi pipeline route from Algeria to Sardinia to analyze the buried salt distribution, rates of fault displacements, and frequency and lateral extent of submarine slope failures. Crossing the convergent African/Nubian–European plate boundary, the southern section of the pipeline route traverses continental shelves and slopes of Algeria and Sardinia as well as the Algerian abyssal plain of the western Mediterranean. Deeply buried Messinian-aged salt is present throughout this area. Being less dense and more buoyant than the overburden sediment, the salt tends to flow upward to form diapiric structures that, in turn, result in the formation of faults and landslides in the overlying sediment. Measured offsets from seismic profiles of different resolutions were compared with predicted sediment age at depth of each offset, yielding an average rate of fault displacement of 1.5 cm/kiloyear (ky). The highest rates of displacement are along the Cagliari slope near Sardinia (2.5-2.7 cm/ky) and near the convergent plate boundary (2.3 cm/ky). Utilizing the same geophysical data, the frequency and lateral extent of submarine slope failures in the study area can also be linked to the distribution of salt and the influence of salt tectonics. Turbidity currents and hyperpycnal flows are present within the Algerian basin, whereas local debris flows, landslide runouts, and channelized debris flows are present along the Sardinian slope. The low sedimentation rates, determined in this study, suggest that the most recent slope failures related to salt tectonics occurred more than 12,000 years ago.

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Álvarez-Gómez, J. A., ĺ. Aniel-Quiroga, M. González, and L. Otero. "Tsunami hazard at the Western Mediterranean Spanish coast from seismic sources." Natural Hazards and Earth System Sciences 11, no. 1 (January 28, 2011): 227–40. http://dx.doi.org/10.5194/nhess-11-227-2011.

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Abstract. Spain represents an important part of the tourism sector in the Western Mediterranean, which has been affected in the past by tsunamis. Although the tsunami risk at the Spanish coasts is not the highest of the Mediterranean, the necessity of tsunami risk mitigation measures should not be neglected. In the Mediterranean area, Spain is exposed to two different tectonic environments with contrasting characteristics. On one hand, the Alboran Basin characterised by transcurrent and transpressive tectonics and, on the other hand, the North Algerian fold and thrust belt, characterised by compressive tectonics. A set of 22 seismic tsunamigenic sources has been used to estimate the tsunami threat over the Spanish Mediterranean coast of the Iberian peninsula and the Balearic Islands. Maximum wave elevation maps and tsunami travel times have been computed by means of numerical modelling and we have obtained estimations of threat levels for each source over the Spanish coast. The sources on the Western edge of North Algeria are the most dangerous, due to their threat to the South-Eastern coast of the Iberian Peninsula and to the Western Balearic Islands. In general, the Northern Algerian sources pose a greater risk to the Spanish coast than the Alboran Sea sources, which only threaten the peninsular coast. In the Iberian Peninsula, the Spanish provinces of Almeria and Murcia are the most exposed, while all the Balearic Islands can be affected by the North Algerian sources with probable severe damage, specially the islands of Ibiza and Minorca. The results obtained in this work are useful to plan future regional and local warning systems, as well as to set the priority areas to conduct research on detailed tsunami risk.

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BOUCHAIR, K., A. BOUBENDIR, and A. SERRER. "Dynamic changes of psychrotrophic bacterial populations in Algerian refrigerated raw cow milk." Journal of the Hellenic Veterinary Medical Society 72, no. 1 (April 9, 2021): 2773. http://dx.doi.org/10.12681/jhvms.26764.

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The aim of the present study is to evaluate the microbial dynamic changes in raw cow milk during refrigeration. Milk samples were collected from two dairy farms situated in basin and mountain areas in the region of Mila, Algeria. Cold storage of milk samples at 4 °C was used to promote psychrotrophic microbial growth during 10 days. The microbial flora of milk was determined by culture methods and the identification of bacterial isolates was carried using cultural, morphological and biochemical criteria. The variations in total viable count and kinetic parameters of microbial growth were analyzed during refrigeration using Baranyi and Roberts Model. The initial microbial counts ranged from 2.94 ±0.04 to 3.87 ±0.11 log CFU * mL-1 and the maximum growth did not exceed 7.00 ±0.12 log CFU * mL-1. The hygienic limit was surpassed after 2 days in the basin farm and later after 6 days in mountain farm. The generation time varied from 1.20 ±0.55 to 4.18 ±0.22 days in the basin farm and mountain farm respectively. The psychrotrophic bacterial populations were identified as Acinetobacter, Pseudomonas, Aeromonas, Chryseobacterium, Enterococcus and Lactobacillus. The notable delay in microbial growth in milk from the mountain farm compared to the one from basin could be related to indoor/outdoor feeding mode adopted in mountain opposed to indoor feeding in the basin farm. This prolonged shelf-life suggests the possible presence of antimicrobial molecules coming from plants grazed around the farm and the selection in the microbiota of some microbial species with antagonist potential.

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Bentaallah, M. E. A., D. Baghdadi, and N. Cantasano. "Distribution and status of Posidonia oceanica meadows on the North-Western coast of Algeria." Biosystems Diversity 31, no. 3 (July 27, 2023): 255–60. http://dx.doi.org/10.15421/012328.

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Posidonia oceanica is an endemic species of the Mediterranean Sea that in pristine coastal waters forms extensive meadows, which are, actually, exposed to natural and anthropogenic pressures, causing their regression throughout the basin. The aim of our study is to summarise and evaluate current knowledge about the characterisation of Posidonia oceanica along the Western Algerian coast, in order to provide new evidence about the distribution and health status this species. To realize our objectives, we combined extracted data from published articles, theses, results of project reports, in situ observations and laboratory analysis. The results show the presence of the meadows in fifteen coastal zones of Western Algeria, mainly located in shallow surface waters from 0.5 to 18 metres depth.The mean leaf length across all sites ranged from 153 to 667 mm. The mean number of leaves/shoot ranged between 4.7 ± 0.9 and 6.0 ± 0.5 leaves/shoot. Leaf length showed a highly significant difference between the cold and hot season. The data analysis shows that the leaf biometric values and the shoot densities of the P. oceanica are greater than those of Mediterranean samples although these measures tend to decrease deeply. The analyses carried out on structural features of P. oceanica show that the Western Algerian meadows are, globally, in good health status according to standardised scale. The available data on P. oceanica summarised in this article represent an important starting point to build effective plans for understanding levels of environmental threats and for supporting conservation strategies for these important ecosystems. Conversely, the limited information available on this seagrass along the Western Algerian costs only allows the description of some structural features, and permits us to draw overall conclusions on its general health status.

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Testor, P., and J. C. Gascard. "Large scale flow separation and mesoscale eddy formation in the Algerian Basin." Progress in Oceanography 66, no. 2-4 (August 2005): 211–30. http://dx.doi.org/10.1016/j.pocean.2004.07.018.

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Wendt, Jobst, Bernd Kaufmann, and Zdzislaw Belka. "Devonian stratigraphy and depositional environments in the southern Illizi Basin (Algerian Sahara)." Journal of African Earth Sciences 54, no. 3-4 (June 2009): 85–96. http://dx.doi.org/10.1016/j.jafrearsci.2009.03.006.

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CRESPO, MANUEL B., Mª ÁNGELES ALONSO, ALICIA VICENTE, and JOSÉ LUIS VILLAR. "A new North African subspecies in the Helianthemum origanifolium aggregate (H. subg. Plectolobum, Cistaceae)." Phytotaxa 252, no. 4 (March 16, 2016): 263. http://dx.doi.org/10.11646/phytotaxa.252.4.2.

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The Helianthemum origanifolium aggregate is widely diversified, with several subspecies distributed in the western Mediterranean basin. Populations from Morocco and Algeria have been usually referred either to H. origanigolium subsp. origanifolium or to H. origanifolium subsp. molle, a taxon usually considered an eastern Iberian endemic. Detailed studies of those Moroccan and Algerian populations revealed a unique combination of constant macro- and micromorphological traits, allowing the description of a new subspecies to accommodate them, H. origanifolium subsp. africanum. Some floral and fruit characters, together with SEM observations of the indumentum, were found to be reliable and diagnostic for differentiating the new taxon with regard to the other subspecies of the aggregate. Data on the ecology and distribution are also reported for this new subspecies, as well as affinities and divergences with other closely allied taxa are also discussed.

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DUFRESNES, CHRISTOPHE, and PIERRE-ANDRÉ CROCHET. "The valid nomen for the tree frog (genus Hyla) of Tunisia and Eastern Algeria." Zootaxa 4759, no. 4 (April 6, 2020): 597–99. http://dx.doi.org/10.11646/zootaxa.4759.4.12.

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Mediterranean tree frogs, Hyla gr. meridionalis Boettger, 1874 (Anura: Hylidae) are widespread around the Western Mediterranean Basin, where they naturally occur across the Maghreb (Morocco, Algeria, Tunisia). Individuals of diverse Moroccan origins have been introduced and have expanded throughout the Iberian Peninsula, southern France and northern Italy (Liguria), but also on the Canary and Balearic archipelagos (Recuero et al. 2007; Dufresnes et al. 2019). Early molecular studies uncovered several mitochondrial lineages and suggested a major cryptic diversification within this taxon, with Tunisian and eastern Algerian (Numidia) populations carrying deeply divergent haplotypes compared with the rest of the range (Recuero et al. 2007; Stöck et al. 2008; Stöck et al. 2012). While intron markers showed little differentiation (Stöck et al. 2008; Stöck et al. 2012), genome-wide data obtained from RAD-sequencing have supported the deep split suspected from mtDNA (Dufresnes et al. 2018).

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Mohammed, Abbou, Moulay Omar Hassan, Semcha Abdélaziz, and Kazi-Aoual Fatiha. "Characterization of clay deposits in the Adrar region, with a view to their valorization in the building materials industry." MATEC Web of Conferences 149 (2018): 01079. http://dx.doi.org/10.1051/matecconf/201814901079.

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In the context of sustainable local development of the Adrar region, one of the largest regions in the Algerian Sahara. The search for local useful substances has been initiated by the Algerian state to cover the need for building materials in the construction industry. However, from a geological point of view, the Adrar zone is located in the extension of the primary chain of the Ougarta which separates two sedimentary basins of Reggane and Timimoun, as well as the basin of Sbâa. In this context, an experimental study is focused on the characterization of clay deposits, with a view to their valorization in the construction materials industry (ceramics) sector, with the aim of contributing to the use of local materials.

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MOKRANE, Z., Y. BELKACEM, and K. SOUMANI. "First record of Dosima fascicularis (Ellis & Solander, 1786) (Crustacea, Cirripedia) from Algerian waters (Western Mediterranean)." Zootaxa 4559, no. 3 (February 20, 2019): 577. http://dx.doi.org/10.11646/zootaxa.4559.3.9.

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The buoy barnacle Dosima fascicularis is reported from Algerian waters for the first time. Seven specimens were collected in the Bay of Jijel (Western Mediterranean Basin), which constitutes the third record of this species in the Mediterranean Sea. A continuous monitoring program in the Mediterranean for this species is proposed to provide further insights into its distribution.

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MEDDOUR, Malika. "Plädoyer für einen interkulturellen Tourismus in Algerien." ALTRALANG Journal 1, no. 02 (December 31, 2019): 141–52. http://dx.doi.org/10.52919/altralang.v1i02.30.

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ABSTRACT: Algeria has a tourist site known to be a great originality in Africa and the Mediterranean basin, if not worldwide. Despite all these natural, cultural and historical advantages that can satisfy all the motivations inherent in tourism, this sector of economic and social activity has not been sufficiently exploited, especially the inventory of the natural, historic heritage and diversified cultural that allows all types and forms of tourism. Algeria is classified among the lowest tourist destinations despite the large capacity that has and which for the most part remain untapped. This is due to: the weakness of the service, the lack of professionalism, the image of the Algerian situation of the security plan and the non-completion of the reforms. Algeria illustrates this situation, in spite of major tourism assets, a political will accompanied by one of the best legislation that remains flexible and encouraging for any promoter or foreigner. The willingness of the state to take charge of major tourist sites in both identification and servicing, and development of seaside, cultural and Saharan tourism, etc. For this purpose, the following objectives can be summed up to: Developing the hotel infrastructure, standardizing the tourist activity with an upgrade according to international standards and define a communication strategy to make the destination Algeria international unique, while operating a different and specific positioning strategy all around the Mediterranean

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Elmeddahi, Yamina, Abderrahmane Issaadi, Hacene Mahmoudi, Miloud Tahar Abbes, and Goosen Mattheus F.A. "Effect of climate change on water resources of the Algerian Middle Cheliff basin." Desalination and Water Treatment 52, no. 10-12 (August 23, 2013): 2073–81. http://dx.doi.org/10.1080/19443994.2013.831777.

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Bensahla-Talet, Lotfi, and Ahmed Bensahla-Talet. "A new maximum length of the spotted weever, Trachinus araneus Cuvier, 1829 (Perciformes: Trachinidae) from Western Mediterranean (Oran Bay)." Acta Adriatica 61, no. 2 (December 28, 2020): 211–16. http://dx.doi.org/10.32582/aa.61.2.10.

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On the 29th of October 2018, one specimen of the spotted weever, Trachinus araneus measuring 47.3 cm in total length and weighting 968 g was captured by trammel net operating in Oran Bay (Kristel fishery) Western Algerian coast at 100 m depth. Up to date, this length is a new record of maximum length reached for this trachinid in the Mediterranean basin.

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Billi, Andrea, Claudio Faccenna, Olivier Bellier, Liliana Minelli, Giancarlo Neri, Claudia Piromallo, Debora Presti, Davide Scrocca, and Enrico Serpelloni. "Recent tectonic reorganization of the Nubia-Eurasia convergent boundary heading for the closure of the western Mediterranean." Bulletin de la Société Géologique de France 182, no. 4 (July 1, 2011): 279–303. http://dx.doi.org/10.2113/gssgfbull.182.4.279.

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Abstract In the western Mediterranean area, after a long period (late Paleogene-Neogene) of Nubian (W-Africa) northward subduction beneath Eurasia, subduction has almost ceased, as well as convergence accommodation in the subduction zone. With the progression of Nubia-Eurasia convergence, a tectonic reorganization is therefore necessary to accommodate future contraction. Previously-published tectonic, seismological, geodetic, tomographic, and seismic reflection data (integrated by some new GPS velocity data) are reviewed to understand the reorganization of the convergent boundary in the western Mediterranean. Between northern Morocco, to the west, and northern Sicily, to the east, contractional deformation has shifted from the former subduction zone to the margins of the two back-arc oceanic basins (Algerian-Liguro-Provençal and Tyrrhenian basins) and it is now mainly active in the south-Tyrrhenian (northern Sicily), northern Liguro-Provençal, Algerian, and Alboran (partly) margins. Onset of compression and basin inversion has propagated in a scissor-like manner from the Alboran (c. 8 Ma) to the Tyrrhenian (younger than c. 2 Ma) basins following a similar propagation of the cessation of the subduction, i.e., older to the west and younger to the east. It follows that basin inversion is rather advanced on the Algerian margin, where a new southward subduction seems to be in its very infant stage, while it has still to really start in the Tyrrhenian margin, where contraction has resumed at the rear of the fold-thrust belt and may soon invert the Marsili oceanic basin. Part of the contractional deformation may have shifted toward the north in the Liguro-Provençal basin possibly because of its weak rheological properties compared with those of the area between Tunisia and Sardinia, where no oceanic crust occurs and seismic deformation is absent or limited. The tectonic reorganization of the Nubia-Eurasia boundary in the study area is still strongly controlled by the inherited tectonic fabric and rheological attributes, which are strongly heterogeneous along the boundary. These features prevent, at present, the development of long and continuous thrust faults. In an extreme and approximate synthesis, the evolution of the western Mediterranean is inferred to follow a Wilson Cycle (at a small scale) with the following main steps : (1) northward Nubian subduction with Mediterranean back-arc extension (since ~35 Ma); (2) progressive cessation, from west to east, of Nubian main subduction (since ~15 Ma); (3) progressive onset of compression, from west to east, in the former back-arc domain and consequent basin inversion (since ~8–10 Ma); (4) possible future subduction of former back-arc basins.

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Daoudi, Mohamed, Benabdallah Bachir Bouiadjra, Jose Antonio Garcia Charton, Ibrahim El Khalil Behmene, and Farid Hemida. "Growth and mortality of Conger conger (Linnaeus, 1758) (Pisces Congridae) in the Algerian basin." Biodiversity Journal 11, no. 4 (November 22, 2020): 853–60. http://dx.doi.org/10.31396/biodiv.jour.2020.11.4.853.860.

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36

Guerrak, S. "Time and space distribution of Palaeozoic oolitic ironstones in the Tindouf Basin, Algerian Sahara." Geological Society, London, Special Publications 46, no. 1 (1989): 197–212. http://dx.doi.org/10.1144/gsl.sp.1989.046.01.17.

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Kerfah, Rabah, Belkheir Noura, Zakarya Meraimi, and Belkacem Zeghmati. "Experimental investigation of basin solar still with additional condensation chamber under Algerian climatic conditions." Journal of Renewable and Sustainable Energy 9, no. 3 (May 2017): 033704. http://dx.doi.org/10.1063/1.4990816.

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HAMDI-AISSA, BELHADJ, VINCENT VALLES, ALAIN AVENTURIER, and OLIVIER RIBOLZI. "Soils and Brine Geochemistry and Mineralogy of Hyperarid Desert Playa, Ouargla Basin, Algerian Sahara." Arid Land Research and Management 18, no. 2 (April 2004): 103–26. http://dx.doi.org/10.1080/1532480490279656.

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Foudili, Djabir, Abderrezak Bouzid, Mohamed Chérif Berguig, Said Sofiane Bougchiche, Abdeslam Abtout, and Mehdi A. Guemache. "Investigating karst collapse geohazards using magnetotellurics: A case study of M'rara basin, Algerian Sahara." Journal of Applied Geophysics 160 (January 2019): 144–56. http://dx.doi.org/10.1016/j.jappgeo.2018.11.011.

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Lamiri, Selma, Zohir Radi, and Khalissa Layadi. "Geodynamic evolution of north-east Algerian basin: 3D velocity model Reveals high-temperature flow." Journal of African Earth Sciences 209 (January 2024): 105122. http://dx.doi.org/10.1016/j.jafrearsci.2023.105122.

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Boukhanef, Issam, Anna Khadzhidi, Lyudmila Kravchenko, Zeroual Ayoub, and Kastali Abdennour. "Modeling of solid sediment transport in mountain rivers." E3S Web of Conferences 175 (2020): 12002. http://dx.doi.org/10.1051/e3sconf/202017512002.

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In Algeria, the problems of erosion and sediment transport are critical, since they have the most dramatic consequences of the degradation of agricultural soils on the one hand and the siltation of the dam on the other .The sediment transport in the Algerian basins is very important especially during the periods of floods, It is in this sense that this study, which consists of estimating the sediment transport in suspension and determining the models of relation linking the liquid discharge and the sediment discharge in order to estimate the solid transport in the absence of suspended sediments concentration data at the Sidi Akkacha station at the outlet of the basin of Oued Allala which is subject to a high water erosion, it degrades from one year to the other under the effect of this phenomenon especially during the floods which drain high amounts of fine particles exceeding in general, the concentration of 150 g/l, the results obtained from the application of the models are very encouraging since the correlation between liquid and solid discharge exceeds 80 %.

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Bensahla-Talet, Lotfi, and Hichem Adda Neggaz. "A review on maximum length of the greater weever Trachinus draco Linnaeus 1758 (Perciformes: Trachinidae) with a new maximum length from Oran Bay (Western Algeria)." Aquatic Research 4, no. 1 (2021): 55–64. http://dx.doi.org/10.3153/ar21005.

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On the 15th April 2017, one female specimen of the greater weever, Trachinus draco measuring 44.69 cm in total length and weighting 885 g was captured by trammel net in Oran Bay (Cape Rousseau) at 120 m depth. Up to date, this length is a new record of maximum length reached for this trachinidae for Algerian waters and the second maximum length recorded in Mediterranean basin according to Fischer et al., 1987 observation noted at 45 cm.

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Garreau, P., F. Dumas, S. Louazel, A. Stegner, and B. Le Vu. "High‐Resolution Observations and Tracking of a Dual‐Core Anticyclonic Eddy in the Algerian Basin." Journal of Geophysical Research: Oceans 123, no. 12 (December 2018): 9320–39. http://dx.doi.org/10.1029/2017jc013667.

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44

Salas, José, Claude Millot, Jordi Font, and Emilio Garcı́a-Ladona. "Analysis of mesoscale phenomena in the Algerian basin observed with drifting buoys and infrared images." Deep Sea Research Part I: Oceanographic Research Papers 49, no. 2 (February 2002): 245–66. http://dx.doi.org/10.1016/s0967-0637(01)00052-8.

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Santos-Muñoz, D., M. L. Martín, M. Y. Luna, and A. Morata. "Diagnosis and numerical simulations of a heavy rain event in the Western Mediterranean Basin." Advances in Geosciences 7 (February 14, 2006): 105–8. http://dx.doi.org/10.5194/adgeo-7-105-2006.

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Abstract. The heavy rain event of November 2001 in the western Mediterranean area was synoptically characterized by the presence of a long-lived Omega blocking geopotential pattern. A set of mesoscale numerical simulations using MM5 is performed to investigate the mechanisms responsible for the convection development through several output diagnosis. A potential vorticity evolution showed how dry air masses were extruded from the stratospheric levels promoting strong cyclonic circulation at all levels. Moreover, a deep vertical column of high relative humidity over the Algerian coastline maintained the few and geographically confined convective cells responsible for the heavy precipitation. Mesoscale environment parameters indicated enhanced conditional instability through a deep troposphere layer. Also, strong vertical wind shear values, higher than 50 ms–1 over the troposphere, were derived, indicating enough strength to promote necessary conditions to organize and keep mesoscale convective structures.

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46

Capó, Esther, Alejandro Orfila, Evan Mason, and Simón Ruiz. "Energy Conversion Routes in the Western Mediterranean Sea Estimated from Eddy–Mean Flow Interactions." Journal of Physical Oceanography 49, no. 1 (January 2019): 247–67. http://dx.doi.org/10.1175/jpo-d-18-0036.1.

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AbstractEnergy conversion routes are investigated in the western Mediterranean Sea from the eddy–mean flow interactions. The sources of eddy kinetic energy are analyzed by applying a regional formulation of the Lorenz energy cycle to 18 years of numerical simulation at eddy-resolving resolution (3.5 km), which allows for identifying whether the energy exchange between the mean and eddy flow is local or nonlocal. The patterns of energy conversion between the mean and eddy kinetic and potential energy are estimated in three subregions of the domain: the Alboran Sea, the Algerian Basin, and the northern basin. The spatial characterization of the energy routes hints at the physical mechanisms involved in maintaining the balance, suggesting that flow–topography interaction is strongly linked to eddy growth in most of the domain.

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47

Feliú, Guillermo, Marc Pagano, Pamela Hidalgo, and François Carlotti. "Structure and function of epipelagic mesozooplankton and their response to dust deposition events during the spring PEACETIME cruise in the Mediterranean Sea." Biogeosciences 17, no. 21 (November 12, 2020): 5417–41. http://dx.doi.org/10.5194/bg-17-5417-2020.

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Abstract. The PEACETIME cruise (May–June 2017) was a basin-scale survey covering the Provencal, Algerian, Tyrrhenian, and Ionian basins during the post-spring bloom period and was dedicated to tracking the impact of Saharan dust deposition events on the Mediterranean Sea pelagic ecosystem. Two such events occurred during this period, and the cruise strategy allowed for the study of the initial phase of the ecosystem response to one dust event in the Algerian Basin (during 5 d at the so-called “FAST long-duration station”) as well as the study of a latter response to another dust event in the Tyrrhenian Basin (by sampling from 5 to 12 d after the deposition). This paper documents the structural and functional patterns of the zooplankton component during this survey, including their responses to these two dust events. The mesozooplankton were sampled at 12 stations using nets with two different mesh sizes (100 and 200 µm) that were mounted on a Bongo frame for vertical hauls within the depth layer from 0 to 300 m. The Algerian and Tyrrhenian basins were found to be quite similar in terms of hydrological and biological variables, which clearly differentiated them from the northern Provencal Basin and the eastern Ionian Basin. In general, total mesozooplankton showed reduced variations in abundance and biomass values over the whole area, with a noticeable contribution from the small size fraction (<500 µm) of up to 50 % with respect to abundance and 25 % with respect to biomass. This small size fraction makes a significant contribution (15 %–21 %) to the mesozooplankton fluxes (carbon demand, grazing pressure, respiration, and excretion), which is estimated using allometric relationships to the mesozooplankton size spectrum at all stations. The taxonomic structure was dominated by copepods, mainly cyclopoid and calanoid copepods, and was completed by appendicularians, ostracods, and chaetognaths. Zooplankton taxa assemblages, analyzed using multivariate analysis and rank frequency diagrams, slightly differed between basins, which is in agreement with recently proposed Mediterranean regional patterns. However, the strongest changes in the zooplankton community were linked to the abovementioned dust deposition events. A synoptic analysis of the two dust events observed in the Tyrrhenian and Algerian basins, based on the rank frequency diagrams and a derived index proposed by Mouillot and Lepretre (2000), delivered a conceptual model of a virtual time series of the zooplankton community responses after a dust deposition event. The initial phase before the deposition event (state 0) was dominated by small-sized cells consumed by their typical zooplankton filter feeders (small copepods and appendicularians). The disturbed phase during the first 5 d following the deposition event (state 1) then induced a strong increase in filter feeders and grazers of larger cells as well as the progressive attraction of carnivorous species, leading to a sharp increase in the zooplankton distribution index. Afterward, this index progressively decreased from day 5 to day 12 following the event, highlighting a diversification of the community (state 2). A 3-week delay was estimated for the index to return to its initial value, potentially indicating the recovery time of a Mediterranean zooplankton community after a dust event. To our knowledge, PEACETIME is the first in situ study that has allowed for the observation of mesozooplankton responses before and soon after natural Saharan dust depositions. The change in the rank frequency diagrams of the zooplankton taxonomic structure is an interesting tool to highlight short-term responses of zooplankton to episodic dust deposition events. Obviously dust-stimulated pelagic productivity impacts up to mesozooplankton in terms of strong but short changes in taxa assemblages and trophic structure, with potential implications for oligotrophic systems such as the Mediterranean Sea.

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Renima, Mohamed, Mohamed Remaoun, Abdelkader Boucefiane, and Abdelkader Sadeuk Ben Abbes. "Regional modelling with flood-duration-frequency approach in the middle Cheliff watershed." Journal of Water and Land Development 36, no. 1 (March 1, 2018): 129–41. http://dx.doi.org/10.2478/jwld-2018-0013.

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AbstractThis study describes a statistical approach of watercourses hydrological regimes in flood, taking into account the latter duration d and return period T. The choice of Middle Cheliff watershed as study area is linked to disasters strong return period in the western region of Algeria. The Midlle Cheliff catchment basin, located in northwest Algeria, has particularly experienced severe floods over the last years. In view of the recurrence of these unusual events, the estimation and the predetermination of floods extreme quantiles are a strategic axis for prevention against floods in this region. The a curves are first of all locally determined, directly from a statistical analysis of flow continuously exceeded during a duration d (QCXd) on different durations from available data of the study region. Then, these curves are compared to those obtained by application of different regional models VFS (Vandenesse, Florac and Soyans) in which two indices of the watershed characteristic flood are taken into account, a descriptive duration of the flood dynamics (D) and the instantaneous maximal annual flow of 10 year return period (QIXA10). The final choice of the model is based on verification of certain criteria, such as: Nash and the root mean squared error (RMSE). The closest regional models to the local ones are Florac’s for low duration and return periods, and Vandenesse’s for large return periods, for different durations. These results could be used to build regional Q-d-F curves on ungauged or partially gauged Algerian basins.

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Hafid, Feyrouz, Aziez Zeddouri, Hichem Zerrouki, Badreddine Saadali, Lassaad Ghrieb, and Asma Sid. "Use of Hydro-chemical Tools to Improve Definitions of the North-Western Sahara Aquifer System, Case of Ouargla Groundwater, Algeria." Environmental Research, Engineering and Management 79, no. 1 (April 11, 2023): 133–47. http://dx.doi.org/10.5755/j01.erem.79.1.33057.

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The North-Western Sahara Aquifer System (NWSAS) is a complex multi-layered aquifer system with extraordinary continental groundwater reserves. This largest aquifer in the world straddles three countries: Algeria, Libya, and Tunisia. It contains more than 50,000 billion cubic meters of water; of which, 70% is in Algerian territory in the southeast of the country. This water is the result of accumulation over 1 million years. In the Wadi Mya basin (Algeria), this system is characterized by two overlaid aquifer systems: the complex terminal (CT), a shallow aquifer housed in the Senonian-Eocene and Mio-Pliocene formations, and the continental intercalary (CI), a deep aquifer hosted in the Albian, Aptian and Barremian formations. The main purpose of this study is to carry out a correlation between the geochemical composition of the water and the facies of the aquifer formation. The adopted approach will allow deciphering the hydro-chemical relationships between the different levels of the two aquifer systems in the Wadi Mya basin. To acquire the chemical composition of water, the study method goes through a targeted sampling and physicochemical analysis of water followed by a statistical analysis as well as correlation and geochemical modelling: the interpretation of specific diagrams (Piper), correlations between chemical elements in binary graphs, and principal component analysis (PCA). The performed geochemical modelling by examining the saturation index and chemical balance of water helps to better understand the origin of mineralization, elucidate the mixing of waters originating from different aquifers, as well as highlight the relationship between deep and shallow aquifers in the Wadi Mya Basin hydrodynamic conversion. The obtained results indicate that the overall mineralization occurring within the study area is dominated by sodium chloride and calcium chloride-sulfate facies. This can be explained by the dissolution of halite, gypsum, and anhydrite evaporitic rocks, intercalated in the aquifer matrix besides the effects of the extended stay of fossil waters with low recharging and cation exchange reactions resulting from water-rock interactions. The interference recorded between the geochemical signatures of the two aquifers favors the hypothesis of interconnection between aquifers through fractures. Through the implementation of such academic research, this invaluable source of life will stay sustainable for future generations.

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Hami, Khelifa, Ibrahim Zeroual, Talhi Abdelkrim, and Djelloul Zenati. "Geomatic Approach and Geophysical Interpretation of the Hydrogeological Basin of the Hassi Naga Region (Algerian Southwest)." International Journal of Environment, Agriculture and Biotechnology 3, no. 2 (2018): 641–46. http://dx.doi.org/10.22161/ijeab/3.2.44.

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Journal articles on the topic 'Algerian basin'

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