bascule de visibilité Search & Display Options

Tout Sélectionner    Désélectionner
 |   | 
Détails
   print
  Enregistrements Liens
Auteur (up) Boukef, I.; Bejaoui, B.; Hassan, M.B.; Mraouna, R.; Got, P.; Harzallah, A.; Elbour, M. url  openurl
  Titre Spatial distribution and decay rates of coliforms in the sediments and water column of the bizerte lagoon Type Article scientifique
  Année 2012 Publication Revue Abrégée Vie Milieu  
  Volume 62 Numéro 1 Pages 29-36  
  Mots-Clés bizerte lagoon; coastal waters; contamination; environmental-conditions; escherichia coli decay; estuarine; fecal indicator bacteria; pathogenic bacteria; pollution; recreational waters; seasonal survey; seawater; sunlight; sunlight inactivation; total coliform  
  Résumé In order to assess the impact of bacterial input loads in Bizerte lagoon (Northern Tunisia), a seasonal survey was done for total coliform bacteria covering the whole lagoon area, to reproduce and prevent dispersion of input loads of terrestrial discharges in the lagoon. Effect of solar radiation on Escherichia coli strains was investigated using seawater microcosms comparatively exposed to sunlight and dark conditions. The results revealed (i) high charges of coliforms in the sediment rather than in the water column, (ii) total coliforms increased periodically with season in both compartments, (iii) anthropogenic discharges influence coastal areas of the lagoon, and (iv) solar radiation has an effect on decay rate of E. coli maintained in microcosm experiments.  
  Adresse  
  Auteur institutionnel Thèse  
  Editeur Lieu de Publication Éditeur  
  Langue English Langue du Résumé Titre Original  
  Éditeur de collection Titre de collection Titre de collection Abrégé  
  Volume de collection Numéro de collection Edition  
  ISSN 0240-8759 ISBN Médium  
  Région Expédition Conférence  
  Notes Approuvé pas de  
  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 846  
Lien permanent pour cet enregistrement
 

 
Auteur (up) Boukef, I.; El Bour, M.; Al Gallas, N.; El Bahri, O.; Mejri, S.; Mraouna, R.; Ben Aissa, R.; Boudabous, A.; Got, P.; Troussellier, M. url  doi
openurl 
  Titre Survival of Escherichia coli Strains in Mediterranean Brackish Water in the Bizerte Lagoon in Northern Tunisia Type Article scientifique
  Année 2010 Publication Revue Abrégée Water Environ Res  
  Volume 82 Numéro 11 Pages 2249-2257  
  Mots-Clés bizerte lagoon; brackish water; coastal waters; cytotoxicity; enteric bacteria; escherichia coli; fecal-coliforms; marine waters; salmonella-typhimurium; seawater microcosms; sewage; shigella-dysenteriae type-1; sunlight; survival; viability; virulence  
  Résumé This study investigated survival and virulence of Escherichia coli strains exposed to natural conditions in brackish water. Two E. coli strains (O126:B16 and O55:B5) were incubated in water microcosms in the Bizerte lagoon in Northern Tunisia and exposed for 12 days to natural sunlight in June (231 to 386 W/m(2), 26 +/- 1 degrees C, 30 g/L) and in April (227 to 330 W/m(2), 17 +/- 1 degrees C, 27 g/L) or maintained in darkness for 21 days (17 +/- 1 degrees C, 27 g/L). The results revealed that sunlight was the most significant inactivating factor (decrease of 3 Ulog within 48 hours for the two strains) compared to salinity and temperature (in darkness). Survival time of the strains was prolonged as they were maintained in darkness. Local strain (E. coli O55:B5) showed better survival capacity (T(90) = 52 hours) than E. coli O126:B16 (T(90) = 11 h). For both, modifications were noted only for some metabolic activities of carbohydrates hydrolysis. Cytotoxicity of the two strains, tested on Vero cell, was maintained during the period of survival. Water Environ. Res., 82, 2249 (2010).  
  Adresse  
  Auteur institutionnel Thèse  
  Editeur Lieu de Publication Éditeur  
  Langue English Langue du Résumé Titre Original  
  Éditeur de collection Titre de collection Titre de collection Abrégé  
  Volume de collection Numéro de collection Edition  
  ISSN 1061-4303 ISBN Médium  
  Région Expédition Conférence  
  Notes Approuvé pas de  
  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 864  
Lien permanent pour cet enregistrement
 

 
Auteur (up) Draredja, M.A.; Frihi, H.; Boualleg, C.; Abadie, E.; Laabir, M. doi  openurl
  Titre Distribution of dinoflagellate cyst assemblages in recent sediments from a southern Mediterranean lagoon (Mellah, Algeria) with emphasis on toxic species Type Article scientifique
  Année 2020 Publication Revue Abrégée Environ. Sci. Pollut. Res.  
  Volume Numéro Pages  
  Mots-Clés alexandrium-catenella; bizerte lagoon; coastal waters; cochlodinium-polykrikoides; Dinoflagellate cysts; Diversity; Environmental factors; genus alexandrium; harmful algal blooms; Mellah lagoon; northwestern indian-ocean; resting cysts; Spatial distribution; spatial-distribution; surface sediments; Toxic species  
  Résumé This is the first study on the dinoflagellate cysts in Algerian waters and in Mellah Lagoon (South Western Mediterranean), located within a protected reserve. In total, 42 species of dinocysts belonging to 7 orders, 12 families and 23 genera, were identified in the 26 superficial sediment samples from Mellah Lagoon. The distribution of dinocysts in the sediment of this lagoon is heterogeneous. Indeed, their abundance oscillates between 1 and 315 cysts g(-1) dry sediment (DS). Cyst morphotype assemblages were dominated by a few numbers of species: Alexandrium minutum (15.87%), Gonyaulax verior (9.81%), Protoperidinium spp. (7.74%), Alexandrium affine (7.05%), Scrippsiella trochoidea (6.67%), and Alexandrium pseudogonyaulax (6.19%). There is a positive correlation between the density of cysts and the depth (r = 0.61; p < 0.05), organic matter (r = 0.70; p < 0.05), water content (r = 0.71; p < 0.05), and the fine fraction of sediment (r = 0.74; p < 0.05). Surprisingly, although the Mellah Lagoon is almost semi-closed, it holds an important specific richness in dinocysts (42 species) higher than others observed in Mediterranean lagoons. However, cyst abundances are low compared to other lagoons in the Mediterranean Sea. Finally, the presence of dinocysts of Alexandrium catenella/tamarense, A. minutum, and Gymnodinium catenatum associated to paralytic shellfish toxins, A. pseudogonyaulax which produces goniodomin A, also Protoceratium reticulatum and Gonyaulax spinifera complex which produce yessotoxins, needs to implement a monitoring program to prevent a potential human intoxication due to the consumption of contaminated sea products by these potent neurotoxins.  
  Adresse  
  Auteur institutionnel Thèse  
  Editeur Lieu de Publication Éditeur  
  Langue English Langue du Résumé Titre Original  
  Éditeur de collection Titre de collection Titre de collection Abrégé  
  Volume de collection Numéro de collection Edition  
  ISSN 0944-1344 ISBN Médium  
  Région Expédition Conférence  
  Notes WOS:000529493300024 Approuvé pas de  
  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2796  
Lien permanent pour cet enregistrement
 

 
Auteur (up) Goni-Urriza, M.; Moussard, H.; Lafabrie, H.; Carré, C.; Bouvy, M.; Sakka Hlaili, A.; Pringault, O. doi  openurl
  Titre Consequences of contamination on the interactions between phytoplankton and bacterioplankton Type Article scientifique
  Année 2018 Publication Revue Abrégée Chemosphere  
  Volume 195 Numéro Pages 212-222  
  Mots-Clés bizerte lagoon; bacterial communities; polycyclic aromatic-hydrocarbons; surface sediments; functional diversity; ecosystem; sediment resuspension; coastal lagoon; nutrient enrichment; tropical lagoon  
  Résumé Sediment resuspension can provoke strong water enrichment in nutrients, contaminants, and microorganisms. Microcosm incubations were performed in triplicate for 96 h, with lagoon and offshore waters incubated either with sediment elutriate or with an artificial mixture of contaminants issued from sediment resuspension. Sediment elutriate provoked a strong increase in microbial biomass, with little effects on the phytoplankton and bacterioplankton community structures. Among the pool of contaminants released, few were clearly identified as structuring factors of phytoplanktdn and bacterioplankton communities, namely simazine, Cu, Sn, Ni, and Cr. Effects were more pronounced in the offshore waters, suggesting a relative tolerance of the lagoon microbial communities to contamination. The impacts of contamination on the microbial community structure were direct or indirect, depending on the nature and the strength of the interactions between phytoplankton and bacterioplankton. (C) 2017 Elsevier Ltd. All rights reserved.  
  Adresse  
  Auteur institutionnel Thèse  
  Editeur Lieu de Publication Éditeur  
  Langue English Langue du Résumé Titre Original  
  Éditeur de collection Titre de collection Titre de collection Abrégé  
  Volume de collection Numéro de collection Edition  
  ISSN 0045-6535 ISBN Médium  
  Région Expédition Conférence  
  Notes Approuvé pas de  
  Numéro d'Appel MARBEC @ alain.herve @ collection 2265  
Lien permanent pour cet enregistrement
 

 
Auteur (up) Leblad, B.R.; Amnhir, R.; Reqia, S.; Sitel, F.; Daoudi, M.; Marhraoui, M.; Abdellah, M.K.O.; Veron, B.; Er-Raioui, H.; Laabir, M. doi  openurl
  Titre Seasonal variations of phytoplankton assemblages in relation to environmental factors in Mediterranean coastal waters of Morocco, a focus on HABs species Type Article scientifique
  Année 2020 Publication Revue Abrégée Harmful Algae  
  Volume 96 Numéro Pages 101819  
  Mots-Clés bay; bizerte lagoon; climate-change; domoic acid; Environmental factors; gymnodinium-catenatum; HABs; harmful algal blooms; Phytoplankton diversity; pseudo-nitzschia; psp toxins; shellfish; SW Mediterranean; temperature; Toxins  
  Résumé Studies on phytoplankton and in particular Harmful Algal Blooms (HABs) species in southern Mediterranean waters are scarce. We performed from April 2008 to June 2009 weekly investigations on microphytoplankton community structure and abundance in two contrasted marine ecosystems located in the western Moroccan Mediterranean coast, M'diq Bay and Oued Laou Estuary. Simultaneously, we measured the main physico-chemical parameters. Globally, the two studied areas showed comparable values of the assessed abiotic environmental factors. Temperature and salinity followed seasonal variation with values ranging from 13.5 degrees C to 21.4 degrees C and 31 to 36.8, respectively. Average nutrient values in surface water ranged from 0.7 to 45.76 mu M for dissolved inorganic nitrogen, 0.02-2.10 mu M for PO4 and 0.23-17.46 mu M for SiO4 in the study areas. A total of 92 taxa belonging to 8 taxonomic classes were found. The highest number of microphytoplankton abundance reached 1.2 x 10(6) cells L-1 with diatoms being the most abundant taxa. Factorial Discriminant Analysis (FDA) and Spearman correlation test showed a significant seasonal discrimination of dominant microphytoplankton species. These micro-organisms were associated with different environmental variables, in particular temperature and salinity. Numerous HABs species were encountered regularly along the year. Although Dinophysis species and Prorocentrum lima were present in both sites, no Lipophilic Shellfish Poisoning was detected for the analyzed bivalve mollusks. Domoic acid (DA), produced by toxic species of Pseudo-nitzschia was found with concentrations up to 18 mu g DA g(-1) in the smooth clam Callista chione. Data showed that the observed persistent and dramatic Paralytic Shellfish Poisoning (PSP) intoxication of mollusks resulted probably of Gymnodinium catenatum proliferations in both studied areas. Contrary to C. chione, the cockle Achanthocardia tuberculatum showed a permanent and extremely high toxicity level during the 15 months survey with up to 7545 mu g Equivalent Saxitoxin kg(-1) flesh (ten times higher than the sanitary threshold of 800 tg eqSTX Kg(-1) flesh). The present work highlights for the first time the dynamic of microphytoplankton including HABs species and their associated toxin accumulation in the commercially exploited shellfish in the southern western Mediterranean waters of Morocco. Furthermore, the acquired data will help us to improve the monitoring of HABs species and related toxins in these coastal marine systems.  
  Adresse  
  Auteur institutionnel Thèse  
  Editeur Lieu de Publication Éditeur  
  Langue English Langue du Résumé Titre Original  
  Éditeur de collection Titre de collection Titre de collection Abrégé  
  Volume de collection Numéro de collection Edition  
  ISSN 1568-9883 ISBN Médium  
  Région Expédition Conférence  
  Notes WOS:000541912700003 Approuvé pas de  
  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2820  
Lien permanent pour cet enregistrement
Tout Sélectionner    Désélectionner
 |   | 
Détails
   print

Save Citations:
Export Records: