Ecological status assessment and non-indigenous species in industrial and fishing harbours of the Gulf of Gabès (central Mediterranean Sea)

Environmental Science and Pollution Research - Port Biological Baseline Surveys (PBBS) are standardized surveys of the indigenous and non-indigenous marine biodiversity within harbour activities....     

Monitoring pollution in Tunisian coasts using a scale of classification based on biochemical markers in worms Nereis (Hediste) diversicolor

This paper aims to assess the marine environment quality along the Tunisian coasts using a statistical approach based on biomarkers response in the polychaete worms Nereis (Hediste) diversicolor. Worms were collected from six sites: Bizerta Lagoon, Gargour, Nakta, Mahres, Skhira and from Teboulba considered as a reference site. The biomarkers selected in this work were (1) the activities of cytochrome P450-dependent NADPH cytochrome c reductase (NADPH red) as phase I enzyme, (2) glutathione S-transferase as phase II enzyme and (3) the acetylcholinesterase activity as neurotoxicity marker. Oxidative stress was evaluated using catalase activity and malondialdehyde accumulation. For each biomarker, a discriminatory factor was calculated and a response index was allocated. For each site, a multi-marker pollution index was calculated as the sum of the response index of each of the five more discriminating biomarkers. The results show differences between sites compared with the reference samples. The multi-marker approach confirms that worms from Bizerta and Mahress have been submitted to highly polluted environment. Mahress shows the highest multi-marker pollution index, indicating a highly contamination status.     

Combined biological processing and microfiltration in the treatment of unhairing wastewater

Introduction  

The unhairing step, a part of the beamhouse process, is particularly polluting, generating an alkaline wastewater with high concentrations of organic and inorganic matter. The aim of this study was to evaluate the treatment of this industrial wastewater using a combination of biological and microfiltration processes.     

Photosynthesis and growth responses of pea Pisum sativum L. under heavy metals stress

The present work aimed to study the physiological e ects of cadmium (Cd) and copper (Cu) in pea (Pisum sativum). Pea plants were exposed to increasing doses of cadmium chloride (CdCl2) and copper chloride (CuCl2) for 20 d. The examined parameters, namely root and shoot lengths, the concentration of photosynthetic pigments and the rate of photosynthesis were a ected by the treatments especially with high metals concentrations. The analysis of heavy metals accumulation shows that leaves significantly accumulate cadmium for all the tested concentrations. However, copper was significantly accumulated only with the highest tested dose. This may explain the higher inhibitory e ects of cadmium on photosynthesis and growth in pea plants. These results are valuable for understanding the biological consequences of heavy metals contamination particularly in soils devoted to organic agriculture.     

Phylogeographic study of the dwarf oyster, Ostreola stentina, from Morocco, Portugal and Tunisia: evidence of a geographic disjunction with the closely related taxa, Ostrea aupouria and Ostreola equestris

Despite the economic importance of oysters due to the high aquaculture production of several species, the current knowledge of oyster phylogeny and systematics is still fragmentary. In Europe, Ostrea edulis, the European flat oyster, and Ostreola stentina, the Provence oyster or dwarf oyster, are both present along the European and African, Atlantic and Mediterranean, coasts. In order to document the relationship not only between O. stentina and O. edulis, but also with the other Ostrea and Ostreola species, we performed a sequence analysis of the 16S mitochondrial fragment (16S rDNA: the large subunit rRNA-coding gene) and the COI fragment (COI: cytochrome oxidase subunit I). Oysters were sampled from populations in Portugal (two populations), Tunisia (two populations) and Morocco (one population), identified as O. stentina on the basis of shell morphological characters. Our data supported a high degree of differentiation between O. stentina and O. edulis and a close relationship between O. stentina and both Ostrea aupouria (from New Zealand) and Ostreola equestris (from Mexico Gulf/Atlantic). The status of this geographic disjunction between these closely related species is discussed. Furthermore, although identified in a separate genus Ostreola by Harry (Veliger 28:121–158, 1985), our molecular data on O. stentina, together with those available for the other two putative congeneric species, O. equestris and Ostreola conchaphila, would favour incorporation of Ostreola in Ostrea. Finally, a PCR-RFLP approach allowed the rapid identification of O. edulis and O. stentina.