A new species, Diopatra marocensis , is described from the fine sand Abra alba community, Sidi Boulbra, south Moroccan Atlantic coast. The new species is a member of the D. cuprea complex and is characterized by having crescentic nuchal grooves, short ceratophores, a short branchiate region, four pairs of modified parapodia with bidentate pseudocompound hooks, pectinate setae with 11–20 teeth, limbate setae with conspicuously serrated shelf, and subacicular hooks from setiger 13–15. Eggs of Diopatra marocensis sp. nov. are deposited in the parental tube, where they undergo direct development and remain until the young consist of 32–34 setigers.
The aim of this study was to determine the physicochemical and microbiological quality of Oued Merzeg. The analyzed waters present an organic pollution represented by the concentration of the organic (DBO5, DCO, Pt, PO4 and NH4). However, analysis of physical parameters and indicators of mineralization, conductivity, salinity, chlorides, sulfates, and water sampled showed a significant mineralization. Parameters monitoring fecal contamination, total coliforms (TC), fecal coliforms (FC) and fecal streptococci (FS), reveal a significant fecal contamination. Water quality of Oued Merzeg pleads for non-conformity of water to be used directly in all areas because they exceed the normative limits generally accepted. The principal component analysis (PCA) evaluated and interpreted complex water quality data sets and apportioned of pollution sources to get better information about water quality of Oued Merzeg.
Data on water quality of Oued Zegzel and the characteristics of the sources of degradation are few and far between. In this context, this study concerns the analysis of 18 physico-chemical parameters (SF, T°, pH, O 2 , SM, EC, TDS, Sal, Cl - , SO 4 2- , Ca 2+ , Mg 2+ , TH, NH 4 + , NO 3 - , NO 2 - , PO 4 3- , Oxid) of the waters of this Oued in order to establish a diagnosis of the state of pollution of the surface waters of this river. Thus, water samples were taken from six stations during One year from October 2017 to September 2018 to allow a comparison between the low-water period and the flood period. The analysis results show that the waters of the stations are bicarbonated with calcium and magnesium, reflecting the geological and pedological nature of the terrain crossed by this watercourse. The values of most of the parameters analyzed generally indicate that the waters of Oued Zegzel are good to excellent quality according to the Moroccan surface water standards. Thus, the results of the Principal Component Analysis (PCA) revealed two gradients. The first reflects the degree of organic pollution, while the second describes the mineralization of water. In addition, this PCA made it possible to discriminate between stations according to their physico-chemical data.
La structure et le fonctionnement des peuplements benthiques de substrat meuble de la region de sidi boulbra (cote atlantique marocaine) sont etroitement lies aux parametres physiques du milieu. Ces derniers sont de nature hydroclimatique (stenothermie), hydrodynamique (courants des canaries, upwelling) et hydrosedimentaire (arrivee des eaux de l'oued tensift). En milieu intertidal, le long des plages de type oceanique de la region de sidi boulbra, l'action de la houle regit la distribution des organismes en detruisant la zonation classiquement observee dans les environnements moins exposes. Une communaute a abra alba (wood)-diopatra brevicirris (grube, 1856) des sediments fins plus ou moins envases a ete definie en zone subtidale. La structure de ce peuplement et la repartition des especes sont dependantes des parametres edaphiques (taux de pelites et de matiere organique). En raison de la relative stenothermie des eaux de sidi boulbra liee aux remontees des eaux froides, la majorite des especes subtidales appartiennent a la faune temperee moyenne et la reproduction des especes et leur periode de recrutement auraient tendance a s'etaler pendant toute l'annee. La description des caracteres morphologiques de l'adulte et du developpement larvaire de l'annelide polychete onuphide diopatra brevicirris (grube, 1856) a ete realisee. En conclusion du present travail qui fait partie d'une etude d'impact prealable a l'installation d'une centrale electronucleaire, nous proposons, comme temoin des variations environnementales ulterieures (elevation thermique des eaux a proximite de l'ouvrage), un suivi, suffisamment serre dans le temps, de la reproduction de l'espece subtidale la plus dominante, d. Brevicirris
Development in the genus Diopatra has been reviewed and divided into four patterns, ranging from brooding in the parental tube to presumed broadcast spawning (Paxton, 1993). While some information is available for numerous species, the identity of some is uncertain, or the information is only anecdotal. Only three species have been studied in detail. Eggs of D. cuprea are released in a jelly mass that readily dissolves in sea-water (Allen, 1959). Although natural spawning has not been observed for D. neapolitana, Cazaux (1972) was able to fertilize the eggs artificially and culture the larvae. The larvae of both species are lecithotrophic and free-swimming, indicating that they are broad-cast spawners.
The epilithic diatoms of a periurban watercourse of Casablanca city (Bouskoura stream) were studied from samples taken in 8 stations (distributed in the upstream-downstream direction) for two years (August 2015-July 2017).The recorded diatomic flora consists of 54 species corresponding to 27 genera and belonging to 5 main families: Monoraphids, Naviculaceae, Nitzschiaceae, Araphids and Surirellaceae.This flora is predominantly alkaliphile and characterizes β-mesosaprobe to polysaprobes and eutrophic to hypereutrophic media.Responses assemblage to natural and anthropogenic disturbances were analyzed.Diatom assemblages structure analysis shows that downstream of this watercourse, where pollution is intense, the abundances of pollosensitive taxa such as Achnanthes minutissima, Cymbella affinis are low or even nulls and we are witnessing the appearance of polysaprobe forms such as Nitzschia palea, Nitzschia capitellata and Nitzschia frustulum that tolerate rich environments in organic matter or highly polluted.Spatial variation in species diversity could not highlight changes in water quality at the prospected sites; on the other hand, the change in the percentage of pollutant-tolerant taxa (PTV) revealed the full extent of the alteration due to gradual nutrient and organic matter inputs into the Bouskoura watercourse.In addition, the correlation obtained between this index and the organic pollution index (IPO) is highly significant.Principal component analysis (PCA) highlighted taxonomic differences between stations.The results obtained in this work have emphasized the importance of diatoms as a bioindicator of the health status of this periurban watercourse.
Morocco’s water resources are facing quantity and quality problems. Limited resources due largely to a semi-arid and arid climate and also to the significant deterioration in the quality grounded by different pollutants. Casablancacity (Morocco's economic capital) is one ofMorocco’s parts that best illustrates these phenomena. It shows a considerable increase of the population and continuous development of industrial activities especially in the suburban area. Rivers of this area who suffer the most are the effects of these pressures, what makes compromised of their uses. Merzeg river and their tributary oued Sierni were chosen to illustrate the above impacts. These hydrosystems receive water from the waste water plant (WWTP) of the city ofBerrechidas well as the release of the industrial area of Had Soualem. A companion of 14 months was conducted in order to determine the physicochemical water quality in 7 sampling stations chosen along these hydrosystems. The findings highlighted the extreme high organic load at the level of the Merzeg river and their tributary Oued Sierni as evidenced by the values of the main parameters: BOD5, COD, Ammonium, orthophosphate and total phosphorus.The waters of study stations can be described as bad to very bad. Significant mineralization was highlighted at the level of this stream. This would result from the combined effect of the degradation of the coastal chaouia groundwater and the mineral load of wastewater. The follow-up of the spatio-temporal evolution of organic pollution index “OPI” shows the polluting waters in the stations receiving releases of the STEP of Berrechid and also Had Soualem. The results of the principal component analysis (PCA) have highlighted two gradients. The first reflects the degree of pollution and eutrophication, while the second describes the mineralization of waters and seasonality. Moreover, this PCA allowed discriminating against stations according to their physicochemical data.
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