bascule de visibilité Search & Display Options

Tout Sélectionner    Désélectionner
 |   | 
Détails
   print
  Enregistrements Liens
Auteur 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 (down) 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
 

 
Auteur Soares, A.; Lira, A.S.; Gonzalez, J.G.; Eduardo Nole, L.; Lucena-Fredou, F.; Le Loc'h, F.; Ferreira, B.P.; Fredou, T. doi  openurl
  Titre Feeding habits and population aspects of the spotted goatfish, Pseudupeneus maculatus (Perciformes: Mullidae), on the continental shelf of northeast Brazil Type Article scientifique
  Année (down) 2020 Publication Revue Abrégée Sci. Mar.  
  Volume 84 Numéro 2 Pages 119-131  
  Mots-Clés biodiversity; biology; Brazil; coast; cross-shelf; diet composition; distribution patterns; dynamics; ecology; island; reef fishes; stable isotopes; stomach content analysis; strategy; teleostei  
  Résumé This study provides information about the feeding habits, population aspects and spatial distribution of the spotted goatfish, Pseudupeneus maculatus, along the coast of the tropical Brazilian continental shelf. Distribution patterns are described using length frequencies and catch rates. Stable isotope ratios of carbon (delta C-13) and nitrogen (delta N-15), along with stomach contents, were analysed to determine the diet of the spotted goatfish. Multivariate analysis and numerical indicators of the diet, such as numerical frequency. frequency of occurrence and weight percentage, were computed to evaluate the diet composition. The mean trophic position was defined using both stable isotope ratios and stomach content analysis. The length at first maturity for the species was determined as 13.7 cm. A slight pattern in size distribution was observed, with mean size increasing with depth along the shelf. The diet was mainly composed of crustaceans, teleosts and Polychaeta. No clear dietary difference was found between habitat types, water depth or latitude. Both trophic positions estimated by stable isotopes and stomach contents analysis ranged between levels 3 and 4. P. maculatus was found to be feeding on many rare and infrequent prey items, classifying it as a generalist zoobenthivorous predator, probably due to its efficient search strategy.  
  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 0214-8358 ISBN Médium  
  Région Expédition Conférence  
  Notes WOS:000539067100006 Approuvé pas de  
  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2825  
Lien permanent pour cet enregistrement
 

 
Auteur Hill, S.L.; Hinke, J.; Bertrand, S.; Fritz, L.; Furness, R.W.; Ianelli, J.N.; Murphy, M.; Oliveros‐Ramos, R.; Pichegru, L.; Sharp, R.; Stillman, R.A.; Wright, P.J.; Ratcliffe, N. url  doi
openurl 
  Titre Reference points for predators will progress ecosystem-based management of fisheries Type Article scientifique
  Année (down) 2020 Publication Revue Abrégée Fish and Fisheries  
  Volume 21 Numéro 2 Pages 368-378  
  Mots-Clés adaptive management; Aichi Biodiversity Targets; ecosystem interactions; indirect impacts; management strategy; precautionary approach  
  Résumé Ecosystem-based management of fisheries aims to allow sustainable use of fished stocks while keeping impacts upon ecosystems within safe ecological limits. Both the FAO Code of Conduct for Responsible Fisheries and the Aichi Biodiversity Targets promote these aims. We evaluate implementation of ecosystem-based management in six case-study fisheries in which potential indirect impacts upon bird or mammal predators of fished stocks are well publicized and well studied. In particular, we consider the components needed to enable management strategies to respond to information from predator monitoring. Although such information is available in all case-studies, only one has a reference point defining safe ecological limits for predators and none has a method to adjust fishing activities in response to estimates of the state of the predator population. Reference points for predators have been developed outside the fisheries management context, but adoption by fisheries managers is hindered a lack of clarity about management objectives and uncertainty about how fishing affects predator dynamics. This also hinders the development of adjustment methods because these generally require information on the state of ecosystem variables relative to reference points. Nonetheless, most of the case-studies include precautionary measures to limit impacts on predators. These measures are not used tactically and therefore risk excessive restrictions on sustainable use. Adoption of predator reference points to inform tactical adjustment of precautionary measures would be an appropriate next step towards ecosystem-based management.  
  Adresse  
  Auteur institutionnel Thèse  
  Editeur Lieu de Publication Éditeur  
  Langue en Langue du Résumé Titre Original  
  Éditeur de collection Titre de collection Titre de collection Abrégé  
  Volume de collection Numéro de collection Edition  
  ISSN 1467-2979 ISBN Médium  
  Région Expédition Conférence  
  Notes WOS:000505754400001 Approuvé pas de  
  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2684  
Lien permanent pour cet enregistrement
 

 
Auteur Lacoste, E.; McKindsey, C.W.; Archambault, P. url  doi
openurl 
  Titre Biodiversity–Ecosystem Functioning (BEF) approach to further understanding aquaculture–environment interactions with application to bivalve culture and benthic ecosystems Type Article scientifique
  Année (down) 2020 Publication Revue Abrégée Reviews in Aquaculture  
  Volume Numéro Pages  
  Mots-Clés aquaculture–environment interactions; benthic system; biodiversity; ecosystem functioning; shellfish  
  Résumé Coastal benthic ecosystems may be impacted by numerous human activities, including aquaculture, which continues to expand rapidly. Indeed, today aquaculture worldwide provides more biomass for human consumption than do wild fisheries. This rapid development raises questions about the interactions the practice has with the surrounding environment. In order to design strategies of sustainable ecosystem exploitation and marine spatial planning, a better understanding of coastal ecosystem functioning is needed so that tools to quantify impacts of human activities, including aquaculture, may be developed. To achieve this goal, some possible directions proposed are integrated studies leading to new concepts, model development based on these concepts and comparisons of various ecosystems on a global scale. This review draws on existing literature to (i) briefly summarize the major ecological interactions between off-bottom shellfish aquaculture and the environment, (ii) introduce research on the influence of benthic diversity on ecosystem functioning (BEF relationships) and (iii) propose a holistic approach to conduct aquaculture–environment studies using a BEF approach, highlighting the need for integrated studies that could offer insights and perspectives to guide future research efforts and improve the environmental management of aquaculture.  
  Adresse  
  Auteur institutionnel Thèse  
  Editeur Lieu de Publication Éditeur  
  Langue en Langue du Résumé Titre Original  
  Éditeur de collection Titre de collection Titre de collection Abrégé  
  Volume de collection Numéro de collection Edition  
  ISSN 1753-5131 ISBN Médium  
  Région Expédition Conférence  
  Notes WOS:000514024900001 Approuvé pas de  
  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2720  
Lien permanent pour cet enregistrement
 

 
Auteur Galès, A.; Triplet, S.; Geoffroy, T.; Roques, C.; Carré, C.; Le Floc’h, E.; Lanfranchi, M.; Simier, M.; Roque d’Orbcastel, E.; Przybyla, C.; Fouilland, E. url  doi
openurl 
  Titre Control of the pH for marine microalgae polycultures: A key point for CO2 fixation improvement in intensive cultures Type Article scientifique
  Année (down) 2020 Publication Revue Abrégée Journal of CO2 Utilization  
  Volume 38 Numéro Pages 187-193  
  Mots-Clés Carbon yield; Microalgal diversity; pH; Predators  
  Résumé Recently, CO2 recycling for the production of valuable microalgae has acquired substantial interest. Most studies investigating CO2 conversion efficiency in algal cultures were based on single species, although a stabilising effect of algal diversity on biomass production was recently highlighted. However, addition of CO2 into polyalgal cultures requires a careful control of pH; performance of CO2 conversion, growth and carbon biomass production are affected by pH differently, depending on the species of microalgae. This study investigates the efficiency of CO2 conversion by natural marine algal assemblage cultivated in open, land-based raceways (4.5 m3, 10 m2), working as high rate algal ponds (HRAP). Ponds were enriched with nitrogen and phosphate, pure CO2 was added and algal cultures were grown under three different fixed pH levels: pH 6, 7 and 8. The highest conversion of photosynthetically fixed CO2 into carbon biomass (40 %) was reached at pH 7, an intermediate level, due to the partial CO2 asphyxiation of algal predators (copepods, ciliates), while being under the suboptimal conditions for the development of marine amoebae. Under this pH, the theoretical maximal biological conversion of available CO2 into carbon biomass was estimated to be 60 % in naturally inoculated open ponds.  
  Adresse  
  Auteur institutionnel Thèse  
  Editeur Lieu de Publication Éditeur  
  Langue en Langue du Résumé Titre Original  
  Éditeur de collection Titre de collection Titre de collection Abrégé  
  Volume de collection Numéro de collection Edition  
  ISSN 2212-9820 ISBN Médium  
  Région Expédition Conférence  
  Notes WOS:000531069900021 Approuvé pas de  
  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2727  
Lien permanent pour cet enregistrement
Tout Sélectionner    Désélectionner
 |   | 
Détails
   print

Save Citations:
Export Records: