Copepod community along the Mediterranean coast of Morocco (Southwestern Alboran Sea) during spring

Copepod community along the Mediterranean Moroccan coast was investigated, for the first time, during April 2013. Total abundance varied from 53 to 4557 ind. m-3 and high values were found in coastal waters. Oithona nana and Paracalanus parvus dominated in the entire area and species diversity was decreasing from the West to the East. Hierarchical clustering revealed three groups of stations, depending on their geographic position (western, central and eastern areas). Indicator species analysis pointed out that Clausocalanus furcatus and Gaetanus sp. were significantly associated with Group I, Clausocalanus sp., Centropages sp. and Centropages chierchiae with Group II, whereas Temora longicornis was significantly associated with Group III. Detrended Correspondence Analysis based on the species abundance and environmental variables (temperature, salinity, chlorophyll-a), highlighted a more or less similar setting of stations which was related to salinity and temperature. The presence of three anticyclonic gyres at the northern part of the study area is suggested as the major factor acting on the variability of copepod community along the Mediterranean Moroccan coast

Electrolytic production of thallium metal and its oxide from TI(I) and TI(III) nitrates

266-270<span style="font-size:11.0pt;line-height: 115%;font-family:Calibri;mso-fareast-font-family:" times="" new="" roman";mso-bidi-font-family:="" "times="" roman";mso-ansi-language:en-us;mso-fareast-language:en-us;="" mso-bidi-language:ar-sa"="" lang="EN-US">The cathodic and anodic deposition of thallium as a pure metal or its oxide from different baths containing TI(I) or TI(III)nitrates with some suitable additives has been investigated. The quantity and quality of the metal and its oxide have been found to be dependent on the type of the bath used. The effect of different parameters such as <span style="font-size:11.0pt;line-height:115%;font-family:Calibri;mso-fareast-font-family: " times="" new="" roman";mso-bidi-font-family:arial;mso-ansi-language:en-us;="" mso-fareast-language:en-us;mso-bidi-language:ar-sa"="" lang="EN-US">p<span style="font-size:11.0pt;line-height:115%;font-family:Calibri; mso-fareast-font-family:" times="" new="" roman";mso-bidi-font-family:arial;="" mso-ansi-language:en-us;mso-fareast-language:en-us;mso-bidi-language:ar-sa"="" lang="EN-US">H <span style="font-size:11.0pt;line-height:115%; font-family:Calibri;mso-fareast-font-family:" times="" new="" roman";mso-bidi-font-family:="" "times="" roman";mso-ansi-language:en-us;mso-fareast-language:en-us;="" mso-bidi-language:ar-sa"="" lang="EN-US">(1-12), current density (0.01-4.0 A dm-2), temperature (20-60°C), electrode type (platinum and graphite), metal and additives concentration on the cathodic and anodic efficiencies and on the quality of deposit has been studied. The interfering effect of some cations and anions has also been studied. Spectrophotometric, polarographic, AAS and X-ray diffraction techniques revealed the purity of separated deposit to be 99.9%. A suitable mechanism for the formation of the element and its oxide is suggested. An analytical application for preconcentration and separation of thallium from its natural ores and alloys using the proposed electrolytic method has been found to be satisfactory and successful.</span

Long term variation of sardine Sardina pilchardus spawning along the Atlantic coast of Northwest Africa (21–26°N): characterization and spatiotemporal variability in spawning habitat

Small pelagic fish such as sardine show strong recruitment variability often associated with environmental changes influencing the spawning process and ultimately, affecting population dynamics. Sardine (Sardina pilchardus, Walbaum 1792) is one of the most exploited pelagic species along the northwest African coast. The main spawning occurs during the cold season (autumn—winter). A time-series autumn—winter surveys extending from 1994 to 2015 sampled sardine eggs, along the southern area of the Moroccan Atlantic coast (26°N—21°N) were analyzed. The present work focuses on examining the inter-annual variability of the spawning habitat by analyzing the spatial-temporal variability of sardine egg distribution and density extracted from the data collected over the period 1994—2015. Generalized additive models (GAM) were used to detect the relationships between the sardine distribution, expressed as egg density and the presence or absence data and relevant hydrobiological environmental variables, such as salinity, temperature and zooplankton biomass. The generalized additive models showed significant relationships between the environment variables (SST, SSS and Zooplankton biomass) and sardine density, but not with sardine presence. Given that the study area is characterized by high mesoscale features and significant upwelling activities, the variability of upwelling processes could explain the changes of spawning ground position and thermal windo