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Nouira T.,Higher Institute of Agriculture | Risso C.,CNRS Ecology of Marine Ecosystems and Responses to Stress Laboratory | Chouba L.,National Institute of science and Technologies of the Sea | Budzinski H.,University of Bordeaux 1 | Boussetta H.,Higher Institute of Agriculture
Chemosphere | Year: 2013

An assessment of PCB and PBDE contamination of surface sediments in Monastir Bay was carried out in two contrasted seasons of the year. Samples were collected from 5 sites and analyzed for the ∑7 marker PCBs (i.e. PCBs 28, 52, 101, 118, 138, 153 and 180) and ∑4 PBDE congeners (PBDEs 47, 99, 119 and 153) by GC/ECD. Concentrations of both PCBs and PBDEs showed seasonal variations. PCB concentrations were in the range of 3.1-9.3ngg-1 and 1.1-8.1ngg-1 in wet and dry season respectively, and sediments were considered moderately contaminated with PCBs. All PCBs analyzed were detected in surface sediments. PCB 153 and 52 congeners showed the highest relative abundance in both winter and summer. PBDE concentrations ranged from not detect to 0.1ngg-1, with only BDE-47 congener detected in sediments and only in winter. Analysis of spatial and seasonal variations indicated that PCB distribution is governed by hydrodynamics and temporal variability of inputs. While the PCB contamination appeared to be mainly land-based, PBDEs are suspected to originate from atmospheric deposition. © 2013 Elsevier Ltd. Source

Valls A.,Agrocampus Ouest | Valls A.,University of British Columbia | Gascuel D.,Agrocampus Ouest | Guenette S.,Agrocampus Ouest | Francour P.,CNRS Ecology of Marine Ecosystems and Responses to Stress Laboratory
Marine Ecology Progress Series | Year: 2012

The present study describes the food web and evaluates the effects of a marine protected area (MPA), the Port-Cros National Park (NW Mediterranean Sea), on the marine eco-system inside the reserve and its potential to sustain resources outside the reserve. We built an Ecopath model of the Port-Cros MPA which comprised 41 functional groups and represented an average situation for the period 1998 to 2008. At a high trophic level, fish were dominated by the amberjacks and large dusky grouper groups, 2 abundant top predators playing a central role inb the ecosystem in terms of keystone species and trophic cascades. The biomass accumulation rate estimated with Ecopath could reach 10% yr-1 for large dusky groupers, which is consistent with field observations, suggesting that the MPA succeeded in protecting the species. The total export from the MPA was estimated at a maximum of about 100 tons yr -1, which limits the benefits at a local scale. EcoTroph fishing scenarios showed that the current state of the ecosystem inside the reserve was close to the unexploited state, and that current fishing practices had an insignificant impact. The major effects of the MPA were to protect the high trophic level groups and thus to maintain the functional biodiversity within the reserve. In summary, trophic modeling seems to be a relevant approach to study the effects of MPAs and to improve their management. © Inter-Research 2012. Source

Salapare III H.S.,University of the Philippines at Diliman | Tiquio Ma.G.J.P.,CNRS Ecology of Marine Ecosystems and Responses to Stress Laboratory | Ramos H.J.,University of the Philippines at Diliman
Applied Surface Science | Year: 2013

Posidonia oceanica samples were exposed to argon and oxygen plasma at varying plasma energies. The untreated and treated samples were characterized to study the weight loss, wettability, surface roughness, and surface chemical functionalities. It was observed that oxygen plasma treatment showed greater weight loss than the argon plasma treatment. Superhydrophilic surfaces (θ < 5°) were achieved at 180 kJ argon-plasma treatment and 6 kJ and18 kJ oxygen-plasma treatments. The surface roughness increases as the plasma energies were increased for the argon-plasma treatment; however, opposite trend was seen for the oxygen-plasma treatment. The -CH2 groups and the aliphatic C-H groups were absent from the FT-IR spectra of the superhydrophilic samples. © 2013 Elsevier B.V. All rights reserved. Source

Prato G.,CNRS Ecology of Marine Ecosystems and Responses to Stress Laboratory | Gascuel D.,Agrocampus Ouest | Valls A.,University of British Columbia | Francour P.,CNRS Ecology of Marine Ecosystems and Responses to Stress Laboratory
Marine Ecology Progress Series | Year: 2014

Mass-balance trophic models (Ecopath and EcoTroph) are valuable tools that can be used to describe ecosystem structure and functioning, identify target species to be monitored, and allow comparisons of ecosystem states under different management options. Nevertheless, the Ecopath modelling approach is constrained by 2 major sources of uncertainty: model complexity and input data quality. We developed an approach for identifying the optimum model structure that considers trade-offs between feasibility, complexity, and uncertainty, using a Mediterranean coastal ecosystem as a case study. We began with an existing well-documented and good-quality foodweb model comprising 41 functional groups at Port-Cros National Park, France. Based on this model, we assessed the effects of different aggregation choices, driven by a simplification of sampling effort, on the Ecopath and EcoTroph model outputs. We identified the functional groups in which imprecise biomass input significantly influenced the foodweb model, and measured the relative effects on the ecosystem trophic structure and ecosystem maturity and complexity indices. A simplified model comprising 32 functional groups was identified as the best compromise between model complexity and reliability. High trophic level predators, abundant primary producers, and groups with a high biomass and/or diversified diet significantly influenced the model structure. We concluded that the collection of local and accurate biomass data, especially for the most influential functional groups we identified, should be a priority when developing foodweb models for similar ecosystems. Our method enables simplified and standardized models, while considering both the feasibility and reliability of the Ecopath and EcoTroph applications for Mediterranean coastal ecosystems. © Inter-Research 2014 Source

Arceo H.O.,CNRS Ecology of Marine Ecosystems and Responses to Stress Laboratory | Cazalet B.,University of Perpignan | Alino P.M.,University of the Philippines at Diliman | Mangialajo L.,CNRS Ecology of Marine Ecosystems and Responses to Stress Laboratory | Francour P.,CNRS Ecology of Marine Ecosystems and Responses to Stress Laboratory
Marine Policy | Year: 2013

The management of fisheries resources in the northwestern Mediterranean is traditionally centralized and developed within the framework of coastal states and European Union common policies. In general, it has not been sufficiently effective in reversing the declining situation of fisheries resources and fishers in this region. This paper discusses the feasibility of moving away from a top-down approach in fisheries management towards a more participative and convergent mode of governance in the region. More specifically, the study focuses on MPAs as a fisheries management tool and evaluates their current establishment and management system in the French Mediterranean as a case study for the region. A brief review of the experiences on fisheries and MPA management in the Philippines is also presented to obtain insights on bottom-up and collaborative management approaches. Finally, possible opportunities for adopting a more decentralized and coordinated approach in fisheries management within the French socio-political system, and possibly in the northwestern Mediterranean region, are discussed. These include the existence of fishing community organizations in the region, such as the prud'homies in France and cofradias in Spain, starting with management strategies that are simpler to enforce and more acceptable to direct users, e.g., fishery reserves, and exploring co-management arrangements to manage fisheries at ecologically meaningful but operationally manageable scales as has been proposed by some development organizations. However, effective changes in the system would require major national policy and institutional reforms, social preparation and organizational strengthening which would take time and resources. © 2012 Elsevier Ltd. Source

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