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Vers 1830 paraissent en France les premières traductions des romans maritimes de Fenimore Cooper. On aime aussitôt à les lire, à se gorger de ces récite fantastiques e a vie aventureuse des pirates. Mais l'on regrette que l'auteur soit étranger et l’on cherche un romancier de la mer qui soit français. Au "pays des quatre mers", il devrait être facile d'en dénicher. Mais peines perdues: une enquête en règle ne livre as un seul véritable romancier maritime français! [...]

The Ghar El Melh lagoon is a Mediterranean water body, situated in Northeastern Tunisia, on the Northwestern side of the Gulf of Tunis. The Ghar El Melh lagoon is a vestigial part of the Utique Sea, and this lagoon was largely open at the time of the Roman invasion. Due to a combination of the shape of the coastline and alluvium deposits from the Medjerda River, this small gulf has become progressively closed from the Utique Sea, causing the lagoon to become progressively shaped to its present morphology. The coastal barrier separating the lagoon from the Mediterranean Sea was interrupted, allowing a permanent hydraulic communication across a local opening. The lagoon has an elliptical shape of approximately 28.5 km2 and an average depth of 0.8 m. Due to human activities within the lagoon itself and in the surrounding area, the lagoon ecosystem has suffered a progressive deterioration. This deterioration has led to a reduction in biodiversity resulting mainly in a decrease in fish resources and production.In order to improve the water quality of the lagoon for ecological and economical purposes, a diagnostic survey was carried out to characterize the present site conditions and to provide data for calibration of hydrodynamic and ecological models. The main results of the annual survey of biotic and non-biotic parameters demonstrated the existence of zones within the lagoon, with some seasonal variation. Thus, a decreasing biotic and non-biotic gradient was measured from the area of the lagoon under marine influence towards the bottom of the lagoon, under the continental and anthropogenic influence of the west side. The lagoon could be considered hypereutrophic with an annual average concentration of total phosphorus of 350 mg/m3. In order to conceptualize and optimise hydraulic structures for water quality improvement in the lagoon, a numerical model of the velocity fields (depth averaged) and water depth was used. The hydrodynamic model used was bi-dimensional, adapted for use in shallow lagoons. After model calibration using in-situ measurements, simulations were carried out to analyse the present hydrodynamic condition of the lagoon. Several stagnation zones were detected, which contributed to the altered water quality that was observed. Several management practices were proposed and simulated, aiming to control and improve the internal circulation and water exchange between the lagoon and the Mediterranean Sea. The main goal of these simulations was to improve water mobility inside the lagoon, and thus improve the water quality. The proposed hydraulic development measures consisted mainly of the creation of a new hydraulic communication in the south-eastern area of the lagoon, by dredging the south part of the lake or by channel creation in front of the new communication, reaching the stagnation zones of the lagoon. The impact assessment of the proposed development was verified with simulations using the bi-dimensional hydrodynamic model.An ecological model based on nitrogen and phosphorus cycling, was also developed for Ghar El Melh lagoon. It took into account one ecological compartment, the macro algae, that included Cladophora sp., Ulva sp. and Enteromorpha sp. Algae (A), inorganic nitrogen (NA), inorganic phosphorus (PA), organic nitrogen (NEorg) and organic phosphorus (PEorg), were the main variables of this model. After calibration of the model, a 10-yr simulation showed that all variables demonstrated a steady behaviour and that the lagoon eutrophication level remained. Model sensitivity analysis allowed the choice of some restoration scenarios and the prediction of their impacts on the ecological behaviour of the ecosystem. The simulations showed that wastewater load deviation combined with an increase in the sea-lagoon water exchange, instead of a decrease of nutrient diffusion from the sediments, led to a substantial decrease in the eutrophication level of the lagoon. Indeed, the annual average nutrient concentrations decreased from 270 to 60 mg/m3 for total nitrogen and from 350 to 20 mg/m3 for total phosphorus in the Ghar El Melh lagoon.

Keywords: Lagune, Ghar El Melh, Tunisie, écologie, sels nutritifs, hydrodynamique, modèle, simulation, Lagoon, Ghar El Melh, Tunisia, ecology, nutrients, hydrodynamic, model, simulation

Biological treatment of sewage in waste water plants does not allow elimination of the whole of the microbial load. Discharge of the treated sewage results in viral pollution of river, lakes and seas, a potential hazard for the health that has to be monitored. The amont of virus in waste water beeing low, concentration from the samples brought to the laboratory is rendered necessary. The aim of this study was to evaluate the efficacy of a new adsorption-elution method on glass wool to recover indigenous viruses from effluents of the cities of Cagnes and Nice (Alpes-Maritimes, France). In order to evaluate its efficiency we compared it to the regular adsorption-elution method on glass powder. As a preliminary we determined upon artificially contaminated 5 liter waste waters samples what detection of virus could be performed only in the first 25 ml of the 100 ml eluate, as in the glass powder concentration method. Results show chat virus titers found in that first fraction of eluate were close to those in the total sample. Thus from 3 samples containing 1.60 108 MPNCU/5 l, 1.96 107 MPNCU/5 l and 4.32 104 MPNCU/5 l we found in that first fraction respectively 1.50 104 MPNCU/5 l (94 %), 1.80 107 MPNCU/5 l (92 %) and 3.85 104 MPNCU/5 l (89 %); these recovery rates are not significantly different by comparison of confidence limits. The glass powder method, necessitates preliminary treatment of the sample : acidification to pH 3.5 and adjunction of AICI3 at a final concentration of 5.10-4 M. After flowing the acidified sample through 100 g of borosilicated glass powder at a rate of 10 l/10 min inside a decantation ampulla. Then adsorbed virus may be eluted from the sedimentated glass powder with 100 ml of borate buffer containing 3 % beet extract, pH9 : the first 25 ml were collected into a flask containing 2.5 ml of a mixture of antibacterial and antifungal antibiotics. For the glass wool adsorption method, a 19 cm3 cartridge was packed with 5 g sodocalcic glass wool at a 0.4 g/cm3 density and rinced sequentially with : 10 ml 1N HCl, 10 ml deionised water, 10 ml 1N NaOH and lastly 40 ml deionised water. It was balanced with 200 ml deionised water. The sample, was pumped at a flow rate ca 10 l/h. Enumeration of viruses was performed by inoculating 40 microplate wells containing KB cells, and performing 3 passages 5 days each, after which the number of wells presenting with CPE was determined. This characteristic number allowed calculation of the most probable number of cytopathic units (MPNCU) with the 95 % confidence limit. The Box and Cox analysis of transformation was applied to the data. Since the calculated value of λ approximated zero (λ = - 0.29 for the Cagnes effluent and λ = - 0,062 for the Nice effluent), transformation of the gross data into logarithm was justified. To allow this transformation, the zero had to be substituted for by a value equal to half the limit sensitivity of the method (I well out of 40), i.e. 0.5. Distribution of the data being roughly log-normal, it was then possible to compare the results of the two methods by two-way analysis of variance, cross classification, without replica. The test for factor method was calculated according to the interaction since this factor is fixed. Overall it appeared that all 31 10-liter samples analysed contained viruses when results from bath methods were combined. Still no single method allowed virus recovery in a 100 % of cases, however the glass wool adsorption method found viruses in 29/31 vs 13/31 with the glass powder method. The new method detected virus in 11/13 (85 %) samples from Cagnes waste waters as well as in 18/18 (100 %) from Nice. Quantitative analysis of the viral titers indicates that, titers were higher following the glass wool adsorption method than following the glass powder adsorption method in 11/13 samples from Cagnes treatment plant and in 17/18 from Nice. Thus virus concentrations varied between 0 and 250 MPNCU/l (MGT= 4.6 MPNCU/l) for the Cagnes effluent and between 2 and 60 MPNCU/l (MGT= 7.5 MPNCU/I) for the Nice effluent. For the same samples virus concentrations obtained following glass powder adsorption method varied between 0 and 8.5 MPNCU/l (MGT 0.9 MPNCU/l) for the Cagnes effluent and between 0 and 25.5 MPNCU/l (MOT= 1.3 MPNCU/l1) for the Nice effluent. This difference is statistically significant (p = 0.0119 for the Cagnes effluent and p < 0.0001 for the Nice effluent). Furthermore, when taking into account the origin of the waters analysed, comparison between observed F0.95 (7.94 for the Cagnes waters and 45.78 for the Nice waters) and theoretical F0.95 (4.75 for the Cagnes waters and 4.45 for the Nice waters) leads to the rejection of the hypothesis of identity of the two methods. The discordances observed are an illustration of the fact that concluding to the absence of viruses in a given sample is a matter of method and should be interpreted with prudence. A few drawbacks inherent to the glass powder adsorption method may explain its poorer efficiency : the necessary acidification of the sample to pH 3.5 may be fatal to a proportion of virions; also the flow rate necessary to maintain the fluid layer of glass powder in suspension during the adsorption step is 6 fold higher than that required in the glass wool method (60 l/h vs 10 l/h). Finally the nature of the adsorbing material, sodocalcic vs borosilicated, may be determinent. We can conclude from the present comparative study, to the statistically significant superiority of the glass wool method for virus concentration from treated waste waters.

Keywords: Méthodes, concentration, virus, laine de verre, poudre de verre, effluent, Methods, concentration, virus, glass wool, glass powder, effluent

Les fous de Bassan, published by Anne Hébert in 1982, contributed in many ways to the emergence of new narrative forms and prefigured what would become the contemporary extreme in French-language literature. The Médicis Prize awarded to the novel was a tribute to its inventiveness: its highly wrought structure is a succession of six narratives consisting of “books,” letters, and what might be described, for lack of an appropriate generic term, as a posthumous reverie. This reverie, entitled “Olivia de la Haute Mer,” displays an epigraph from Hans Christian Andersen: “Your heart will break and you will become foam on the sea.” Anne Hébert is able to bring together, in a way that is both fluid and effective, the ancient myth of the bird-shaped sirens and the modern tale known as The Little Mermaid, creating a “disturbingly strange” symbolic and poetic universe in which the siren is in turn predator and prey, lure and sacrificial victim. This enables her, among other things, to subject femininity and male/female relationships to remarkably acute questions.

Although a growing number of studies emphasize the benefits of interaction with nature (Montreal Heart Institute, 2021), few studies specifically address the role of marine environments in nature and adventure based practices. However, so-called “blue environments” have their own characteristics and are recognized for their beneficial effects on physiological and psychological health (White et al., 2020). There are various programs around the world that, through a stay at sea on a sailboat, aim to support individuals and groups experiencing various difficulties (Schijf et al., 2017). Intervention practices that rely on sailing thus offer a singular opportunity for immersion in a marine environment. This article presents research findings and reflections on this phenomenon, which has been little studied to date from a social work perspective. The article is based on the preliminary results of a master's thesis in social work being carried out at the Université du Québec à Rimouski which aims, through a phenomenological approach, to better understand the experience lived by the interveners and participants during a sailing expedition on the St. Lawrence River in a social intervention context.

Radiocarbon chronology of paleogeographic events in Québec since 14 000 BP. A distribution curve of dates on post-glacial marine shells in Eastern Canada was compiled taking into account laboratory error. Most of the variations identified on this curve may be qualitative indicators of secondary climatic fluctuations. Positive values would be related to climatic warming and to rises of mean sea level greater than or equal to isostatic rebound; negative values would indicate a relative lowering of shorelines in relation to the uplifting land and also represent different steps in the déglaciation. Fluctuations in the curve are correlated with paleogeographic events already identified in Quebec and elsewhere. The curve therefore provides a chronological frame of reference, with its limits. The curve shows some major disparities in relation to calendar years. Each date is subject to the limits of the 14C method and to variables modifying initial 14C composition of marine organisms. Therefore the proposed time scale of the chronological frame of reference is divided up into ''14C cold water marine shell" years. Statistical validity is assured because of the large number of uniformly analyzed radiocarbon dates. Paleogeographic relevance can be seen from the persistence of the same modes from one postglacial sea to the other and by good chronological correlations with the events of the Great Lakes area.