Re-thinking Secularism in Post-Independence Tunisia

The victory of a Tunisian Islamist party in the elections of October 2011 seems a paradox for a country long considered the most secular in the Arab world and raises questions about the nature and limited reach of secularist policies imposed by the state since independence. Drawing on a definition of secularism as a process of defining, managing, and intervening in religious life by the state, this paper identifies how under Habib Bourguiba and Zine al-Abidine Ben Ali the state sought to subordinate religion and to claim the sole right to interpret Islam for the public in an effort to win the monopoly over religious symbolism and, with it, political control. Both Bourguiba and Ben Ali relied on Islamic references for legitimacy, though this recourse to religion evolved to face changing contexts, and both sought to define Islam on their own terms. Bourguiba sought to place himself personally at the summit of power, while under Ben Ali the regime forged an authoritarian consensus of security, unity, and ‘tolerance’. In both cases the state politicised Islam but failed to maintain a monopoly over religious symbolism, facing repeated religious challenges to its political authority

What factors drive copepod community distribution in the Gulf of Gabes, Eastern Mediterranean Sea?

International audienceThe spatial and temporal variations in copepod communities were investigated during four oceanographic cruises conducted between July 2005 and March 2007 aboard the R/V Hannibal. A close relationship was observed between the temperature, salinity, hydrographic properties and water masses characterising the Gulf of Gabes. Indeed, water thermal stratification began in May–June, and a thermocline was established at a 20-m depth, but ranged from 25 m in July to more than 30 m in September. The zooplankton community is dominated by copepods representing 69 % to 83 % of total zooplankton. Spatial and temporal variation of copepods in relation to environmental factors shows their close relationship with the hydrodynamic features of the water column. Thermal stratification in the column, established in summer, supports copepod development. In fact, copepod abundance increases gradually with rising water temperature and salinity, starting from the beginning of thermal stratification (May–June 2006) and lasting until its completion (July 2005 and September 2006). When the water column is well mixed (March 2007), copepod abundance decreased. Our finding shows that temperature and salinity seem to be the most important physical factors and thus strongly influence the taxonomic diversity and distribution of the copepod population. They are characterised by the dominance of Oithona nana, representing 75–86 % of total cyclopoid abundance. The most abundant species during the stratification period were O. nana, Acartia clausi and Stephos marsalensis in July 2005 and September 2006. However, during the mixing period, Euterpina acutifrons was more abundant, representing 21 % of the total. Unlike the copepod community, which is more abundant during the period of high stratification, phytoplankton proliferates during semi-mixed conditions

Impact of cigarette butts on microbial diversity and dissolved trace metals in coastal marine sediment

International audience20 21 Cigarette butts are the most common plastic form of litter found in the marine coast, threatening 22 the quality of the seawater and marine life. However, the impact of cigarette butts known to 23 contain toxic chemicals has been investigated to date in very few marine species. This study 24 aimed to evaluate the effects of cigarette filters (smoked or unsmoked) on the microbial 25 diversity inhabiting coastal sediments by high-throughput sequencing of the 16S rRNA genes. 26 Both bacterial structure and metals distribution were impacted by cigarette filter addition in 27 laboratory sediment experiments, compared to control sediment incubations without filter. Both 28 smoked and unsmoked cigarette filters decreased pH and dissolved Cd, Mo and V 29 concentrations in marine sediment incubations, while they increased dissolved Fe, Mn, Zn 30 levels in the surrounding environment. Smoked filters dramatically decreased the relative 31 abundance of the phyla Bacteroidetes and Cyanobacteria, while the members of the phyla 32 Gammaproteobacteria, Firmicutes and Thermotogae were enriched by smoked filters in marine 33 sediments. Bacterial taxa associated with deep marine environments or hydrothermal seep fields 34 were selected by smoked cigarette filters. This study demonstrated for the first time the 35 microbial community changes and impacts from toxic cigarette filters in coastal marine 36 sediments

Abundance and Biomass of the Ciliate Community during a Spring Cruise in the Gulf of Gabes (Eastern Mediterranean Sea, Tunisia)

12 pagesInternational audienceWe studied the spring spatial distribution of the ciliate community coupled with environmental factors along the coast and in the open sea at 30 stations sampled (between 27 May and 9 June 2006) in the Gulf of Gabes (Tunisia, Eastern Mediterranean Sea). A total of 61 taxa belonging to 36 genera and 5 taxonomic classes were identified. The ciliate assemblage was numerically dominated by spirotrichs (86% of total ciliates). This group is largely dominated by the choreotrichs (92%) among which tintinnids represented 99%. The total ciliates abundance showed a gradual decrease from the coastal area to the open sea and an increase from the surface to the bottom. The maximum abundance (400 cells l-1) and biomass (6.29 μgC l-1) were found in station 27, close to Djerba Island. The tinitinnid Rhabdonella spiralis was cosmopolitan, being found almost at every station and at each depth, while other taxa may be exclusive to the neritic area, others to the open sea area. The distribution of species in the Gulf of Gabes seemed most likely influenced by the combined effects of hydrographic conditions, zooplankton predation and urban interferences

Dynamics of dinoflagellates and environmental factors during the summer in the Gulf of Gabes (Tunisia, Eastern Mediterranean Sea)

13 pagesInternational audienceThe summer spatial distribution of the dinoflagellate community along an open coastal sea gradient in the Gulf of Gabes (Tunisia, Eastern Mediterranean Sea), together with environmental factors, were studied. The most dominant families were represented by Gymnodiniaceae (32%), Peridiniaceae (20%), Prorocentraceae (15%), Ceratiaceae (13%) and Ebriaceae (10%). The dinoflagellate community was spatially more concentrated along the coast of the gulf than in the open sea. Eight toxic dinoflagellates were recorded, including Karenia cf. selliformis (37% of total toxic dinoflagellates) which was evenly distributed in both the neritic and open sea areas. Dinocysts contributed 33% of the total motile cells and were more abundant along the coast than in the open sea. This high concentration may be ascribed to nitrogen inputs in the coastal waters of Gabes. The Modified Atlantic Water governed dinoflagellate development in the open sea. The degradation of the water quality due to eutrophication in the Gulf of Gabes may have significant socioeconomic consequences. We suggest that a management framework, similar to that used in freshwater ecosystems, should be developed for the Gulf coast in order to drastically reduce urban interferences

Plankton as biological pump for contaminants in marineecosystems: a trans-Mediterranean approach (MERITE HIPPOCAMPE cruise, April-Mai 2019)

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Prokaryotic Diversity and Dynamics during Dinoflagellate Bloom Decays in Coastal Tunisian Waters

International audience(1) Background: Harmful algal blooms (HABs) can negatively impact marine ecosystems, but few studies have evaluated the microbial diversity associated with HABs and its potential role in the fates of these proliferations. (2) Methods: Marine prokaryotic diversity was investigated using high-throughput sequencing of the 16S rRNA gene during the bloom declines of two dinoflagellates detected in the summer of 2019 along the northern and southern Tunisian coasts (South Mediterranean Sea). The species Gymnodinium impudicum (Carthage, Tunis Gulf) and Alexandrium minutum (Sfax, Gabes Gulf) were identified using microscopy and molecular methods and were related to physicochemical factors and prokaryotic compositions. (3) Results: The abundance of G. impudicum decreased over time with decreasing phosphate concentrations. During the G. impudicum bloom decay, prokaryotes were predominated by the archaeal MGII group (Thalassarchaeaceae), Pelagibacterales (SAR11), Rhodobacterales, and Flavobacteriales. At Sfax, the abundance of A. minutum declined with decreasing phosphate concentrations and increasing pH. At the A. minutum peak, prokaryotic communities were largely dominated by anoxygenic phototrophic sulfur-oxidizing Chromatiaceae (Gammaproteobacteria) before decreasing at the end of the survey. Both the ubiquitous archaeal MGII group and Pelagibacterales were found in low proportions during the A. minutum decay. Contrary to the photosynthetic Cyanobacteria, the photo-autotrophic and -heterotrophic Rhodobacterales and Flavobacteriales contents remained stable during the dinoflagellate bloom decays. (4) Conclusions: These results indicated changes in prokaryotic community diversity during dinoflagellate bloom decays, suggesting different bacterial adaptations to environmental conditions, with stable core populations that were potentially able to degrade HABs

What are the potential drivers of blooms of the toxic dinoflagellate Karenia selliformis ? A 10-year study in the Gulf of Gabes, Tunisia, southwestern Mediterranean Sea

International audienceWe report on a 10-year study of the dynamics of toxic dinoflagellate Karenia selliformis at 20 stations along the nearshore of the Gulf of Gabes (Tunisia) in relation to environmental variables. Dinoflagellates and K. selliformis have dominated the phytoplankton community and K. selliformis blooms have taken place since 2001. Phytoplankton groups showed significant variability among sampling sites, but did not vary significantly from year to year. Redundancy analysis revealed that salinity, nitrate and phosphorus significantly explained the variability of the main phytoplanktonic groups namely, diatoms, dinoflagellates, cyanobacteria and euglenoids, while K. selliformis exhibited a specific pattern. Because of the wide variability in K. selliformis abundance, we tested the influence of environmental variables on its presence/absence using a generalized linear mixed-effect model (GLMM). K. selliformis occurrence had a positive relationship with nitrate and a negative one with total phosphorus. The different spatial gradients of these two chemical variables led to spatial differences in K. selliformis development prevalent near touristic areas. Temperature was also retained in the GLMM and since it rose over the 10 years of the study, it likely supports the expansion of K. selliformis. The discrepancies between model predictions and observed occurrences suggest that consideration of other sources of environmental forcing may improve our understanding of the determinism of K. selliformis dynamics. Our study may be useful in the management of this ecosystem so as to plan for the best disposal options in the treatment of urban and industrial wastes in the gulf's coastal waters

Hydrocarbures Aromatiques Polycycliques (HAPs) et éléments traces métalliques (ETMs) dans les dépôts atmosphériques le long d'un transect Nord-Sud en Méditerranée (campagne Hippocampe)

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