International audienceno abstrac
“Introduced” species of the Algerian coast remains the most undocumented issue in the Mediterranean Sea. Only few studies were dedicated to Introduced species due to the lack of taxonomists. In-depth research on Introduced species along the Algerian coast should provide new data that could explain the spreading mechanisms in the southwestern part of the Mediterranean basin particularly near the Alboran Sea. Introduced species among other related research; of which the outcome is expected in the next few years, is in progress in the southwest Mediterranean basin. The aim of this work is to provide an inventory of available data pertaining to marine species “introduced” in Algerian waters, whether these species were introduced intentionally or accidentally. This large number of Introduced species records covers the period from 1834 to December 2017. Seventy “Introduced” species have been recorded along the Algerian coast, composed by 55.7% true aliens25.7 % range expanding species, 15.7% cryptogenic species and 2,9% vagrant species, with a clear domination of fish (38.57%) and macroalgae (30%). Approximately 348 introduction events have been reported; 64,9 % of them belong to macroalgae and one sighting out of two is done in the central region. The distribution and the status of introduced species in Algeria were evaluated. In total, 20% of the Introduced species can be considered as established along the Algerian coast, in particular the macrophyta, Codium fragile and Ulva lactuca as well as the cryptogenic species, Oculina patagonica, while Asparagopsis armata, A. taxiformis and Caulerpa cylindracea are considered as invasive.
The present study was carried out in order to determine the phytochemical composition of the marine brown alga Cystoseira foeniculacea collected off the coasts of Algeria. After a preliminary fractionation of its organic crude extracts by column chromatography, the resulting fractions were further analysed by 1 H NMR. Even though algal species of the genus Cystoseira are commonly known to produce a wide variety of meroditerpenoids, in the case of C. foeniculacea none of the fractions were found to contain such compounds: most of the fractions showed typical 1 H NMR signals of fatty acids and derivatives (mainly glycerolipids and glycolipids). Nevertheless, the thorough analysis of a sterol-enriched fraction by RP-C 8 HPLC led to the isolation, for the first time from this species, of fucosterol (1) and a mixture of saringosterols (2 and 3). The NMR data of compounds 1-3 were fully determined with the help of 1D and 2D experiments which allowed the reassignment of some attributions in comparison with those reported in the literature. This work also confirms evidence of the oxidative degradation of fucosterol into a C-24 epimeric mixture of saringosterols. ª 2014 Production and hosting by Elsevier B.V. on behalf of King Saud University. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/3.0/).
This study was undertaken to investigate and assess trace metal (Cd, Pb, Cr, and Hg) concentrations in the Cystoseira compressa algae from the coastal city of Bou Ismaïl (Algeria). Spatial and temporal variations in the concentrations of these heavy metals were studied in the following three sampling sites: site 1 and site 2 were major wastewater discharge zones and site 3 was located close to areas with high industrial activity. Seawater, sediments and algae in the wastewater from the three sites were submitted to physico-chemical analyses to determine the concentrations of heavy metals and the level of pollution in the region. The results revealed that site 1 (designed as desalination) and site 2 (designed as industrial waste) were non-compliant, which was attributed to heavy loads of heavy metals and wastewater discharged by industrial activity and absence of regular treatment. Site 3 (designed as cove koali), on the other hand, was noted to represent a reference site. Overall, the results provided evidence for the heavy metal bioaccumulation of algae from the genus Cystoseira and their efficiency for use as biomarkers of pollution in coastal areas.
Macroalgal assemblages have been used as a quality element for the assessment of the ecological status classes (ESCs) in coastal water bodies for the implementation of the European Water Framework Directive (WFD, 2000/60/EC). To assess the suitability of this quality element in the coastal waters off Algiers, seven sampling sites with five (5) replications covering a wide range of anthropogenic pressures were studied during spring and summer 2015. Coverage data for the macroalgae at each sampling site were analyzed at the biological levels of species, i.e., structural (species number, nMDS, clustering, K-dominance and Simper analysis based on Bray-Curtis similarity), and ecological status groups, i.e., functional (nMDS, clustering, K-dominance, ecological evaluation index/EEI-c). Key water variables (temperature, salinity and pH) along with the anthropogenic stress index MALUSI were also estimated. The obtained results revealed a significant effect of anthropogenic stress on the macroalgal assemblages. The structural analysis showed the following: (1) species richness of 86 taxa in total; (2) dominance of Cystoseira amentacea var. stricta (late-successional) associated with Lithophyllum incrustans and Jania rubens at nonimpacted sites and with Ulva rigida, Ulva intestinalis and Caulerpa cylindracea (opportunistic) species at impacted sites; and (3) a higher proportion of low-abundance species in polluted communities than in less polluted communities. The functional analysis showed the following: (1) classification of sites based on multivariate and K-dominance analyses into four groups, three in agreement with the water degradation information and one in agreement with a low salinity influence; (2) classification of sites into "bad", "high", "moderate" and "good" ESCs based on the EEI-c index; and (3) a strong nonlinear relationship (R²=0.85) of the EEI-c index with the MALUSI index. Therefore, the EEI-c index will be a suitable tool to implement a national monitoring program within the scope the WFD along Algerian coasts.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.