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Ernoul L.,Tour du Valat Research Center | Ernoul L.,Aix - Marseille University | Wardell-Johnson A.,University of The Sunshine Coast
Ocean and Coastal Management | Year: 2015

The Integrated Coastal Zone Management (ICZM) protocol for the Mediterranean basin provides a common strategy for coastal management that is applicable to all countries bordering the Mediterranean Sea. Despite the regionalization of ICZM policy, previous studies have shown that ICZM is being implemented differently across the Mediterranean basin. The differences in ICZM implementation could be attributed to the different environmental discourses that are embedded in the perceptions and socio-cultural values in each site. This study analyzed the differences in environmental discourses as they apply to ICZM policy in two Mediterranean Deltas (Rhone Delta in southern France and Gediz Delta in Western Turkey). A cross-section of 39 (Rhone Delta) and 54 (Gediz Delta) participants contributed to a survey questionnaire. Qualitative and quantitative techniques provided insights into complex relationships between environmental ideals, ideologies and practice in the adoption of ICZM principles. The results demonstrated incorporation of ICZM in environmental discourse in both sites with distinct differences in ICZM strategies. Differences in environmental discourses have implications for applying the ICZM protocol. The identification of these differences provides a more effective focus for conservation strategies accounting for specific context. © 2014 Elsevier Ltd. Source

Ernoul L.,Tour du Valat Research Center | Ernoul L.,Aix - Marseille University | Wardell-Johnson A.,University of The Sunshine Coast
Environmental Conservation | Year: 2013

The Integrated Coastal Zone Management protocol of the Barcelona Convention sets governance objectives for countries bordering the Mediterranean Sea. This protocol emphasizes collaborative approaches to acknowledge the role of local people in coastal management. Evaluating the quality of governance processes is critical if coastal zone values are to be effectively managed in times of global climate change. This study examined the structure and attributes of collaborative governance networks in two Mediterranean deltas, the Camargue (France) and Gediz Delta (Turkey). A deliberative social catchment sampling was used to target actors with physical, cultural, social or economic ties. Forty-five different organizations/professions were interviewed using a standardized questionnaire to identify the frequency and quality of contacts, information flows, and subject matter relevant to natural resource management. There were higher levels of degree centrality and reciprocal ties in the Camargue, while the Gediz Delta had a greater homogeneity of actors, with one centralized influential actor. Civil society played a greater role in the Camargue network, and government organizations were more central in the Gediz Delta. The differences between the two sites call into question the use of the same integrated management strategies and suggest the need to acknowledge the importance of existing governance models and relationships within local contexts. © Foundation for Environmental Conservation 2013. Source

Following its high selectivity and low toxicity to nontarget organisms, Bacillus thuringiensis var. israelensis (Bti) has become the most commonly used microbial agent to control mosquitoes worldwide. Considered non-toxic to mammals, birds, fish, plants and most aquatic organisms, Bti direct effects on the nontarget fauna are largely limited to non-biting midges (Chironomidae). Studies addressing the indirect effects of Bti through food web perturbations are scanty and showed no significant results. Mosquito-control in southern France was implemented in 1965 using various insecticides over 400 km of coast. In spite of a high mosquito nuisance, the Camargue wetlands were excluded from this control programme to preserve biodiversity. The expanding use of Bti has prompted the implementation of an experimental mosquito control in 2006 involving 2500 of the 25,000 ha of larval biotopes of the Camargue, accompanied by impact studies on the nontarget fauna. Using birds from natural and human-inhabited areas as model species, we assessed trophic perturbations caused by three years of Bti applications. The preliminary results of this 5-yr programme revealed significant effects of Bti spraying on abundance of reed-dwelling invertebrates serving as food to passerines, as well as on the diet and breeding success of house martins nesting in rural estates and small towns. Very few studies (if any) have provided such compelling evidence of an insecticide affecting vertebrate populations, putting into question the environmental-friendly character of Bti, at least in some areas. The significance of these results are discussed within a wider context and completed with an analysis of the current Bti bibliography to highlight and orient priorities for future research on this topic. © 2011 Elsevier Masson SAS. Source

Jakob C.,Libelo | Poulin B.,Tour du Valat Research Center
Insect Conservation and Diversity | Year: 2016

Bacillus thuringiensis var. israelensis (Bti) has become the most commonly used larvicide to control mosquitoes worldwide. Bti is considered non-toxic to most organisms, except some Diptera such as chironomids, which are a major prey in wetland food webs. Although Odonata are important predators of mosquitoes and chironomids at the larval and adult stages, no study has ever considered the potential indirect effects of Bti on Odonata abundance through trophic interactions. We addressed this topic in the Camargue where 2500 of the 25 000 ha of mosquito larval biotopes are Bti-sprayed (aqueous solution of VectoBac 12AS at 2.5 L ha-1) whenever mosquito larvae appear in water bodies (i.e. 30-50 aerial treatments overall annually). Adult Odonata were surveyed along a 100-m line transect in spring, summer and autumn at three control and three treated sites over a 5-year period. Mean number of species (9.9 vs. 5.2) and of individuals (100 vs. 50) detected per year were significantly higher in control areas compared to Bti-sprayed areas. Bti treatment contributed to 87.3% of the explained variance in Odonata richness, compared to 2.9% for site, 6.8% for year and 3.0% for salinity effects. These results are coherent with other studies carried out in the same area and time period highlighting a lower abundance of chironomids, and a lower intake of odonates by breeding birds in treated areas. We conclude that mosquito control using Bti should be acknowledged as a potential threat to Odonata. © 2016 The Royal Entomological Society. Source

Poulin B.,Tour du Valat Research Center | Lefebvre G.,Tour du Valat Research Center | Paz L.,University College London
Journal of Applied Ecology | Year: 2010

The expanding use of selective pest-control agents provides a unique opportunity to study food web interactions in the field while addressing major environmental issues. Bacillus thuringiensis israelensis (Bti) is the most commonly used microbial agent to control mosquitoes worldwide. Using breeding house martins Delichon urbicum as a model species, we assessed the effect of Bti spraying on foraging rates and chick diet prior to and during 3 years of Bti spraying in the Camargue, France. Some 9051 feeding flights and 14 857 prey items were recorded in the early, mid and late nesting season at up to three control and three treated sites. Breeding parameters were assessed during 1 year at two control and two treated sites. Intake of Nematocera (Diptera sub-order including midges and mosquitoes) and their predators (spiders and dragonflies) decreased significantly at treated sites, concurrently with increase of flying ant intake. Small prey (<2·5 mm) were significantly more taken at treated sites, and large prey (>7·5 mm) at control sites, with lower foraging rates at treated sites. Clutch size and fledgling survival were significantly lower at treated sites relative to control with respectively 2·3 vs. 3·2 chicks produced per nest. Breeding success was positively correlated with intake of Nematocera and their predators at the nest level. No previous study has provided compelling evidence of Bti affecting vertebrate populations following the suppression of prey species. Indirect effects caused by repeated application of Bti through food web interactions warrant more attention.6. Synthesis and applications. Bti is considered the most selective and least toxic agent currently available to control mosquitoes. Mosquito-control programmes should integrate non-biased awareness campaigns and mitigation measures balancing the social demands for mosquito reduction with the factors involved in mosquito proliferation and dispersion. Such measures could consist in improved wetland management; reduction in areas and periods of Bti spraying; consideration of alternatives to Bti spraying, such as mosquito traps; specific measures to reinforce animal populations affected by Bti; and suspension of mosquito control in environmentally sensitive areas where nature preservation is a priority. © 2010 The Authors. Journal compilation © 2010 British Ecological Society. Source

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