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Auteur (up) Avadí, Á.; Vázquez-Rowe, I.; Freon, P.
Titre Eco-efficiency assessment of the Peruvian anchoveta steel and wooden fleets using the LCA+DEA framework Type Article scientifique
Année 2014 Publication Revue Abrégée Journal of Cleaner Production
Volume 70 Numéro Pages 118-131
Mots-Clés Data envelopment analysis; Eco-efficiency; Engraulis ringens; Life cycle assessment; Peru
Résumé The Peruvian anchoveta fishery is currently targeted by a large fleet featuring a wide range of vessel sizes (segments), with highly variable capacities. In addition, the landings of the industrial fleet are used exclusively by the reduction industry, while those performed by small- and medium-scale vessels are destined mainly for direct human consumption. Despite these differences, the entire fleet is made up of purse seiners that perform similar operations when at sea. Therefore, the main aim of this study is to identify the differences in eco-efficiency between the different fleet segments in order to delve into the potential environmental improvements that could be attained through operational benchmarking. To this end, the combined use of Life Cycle Assessment (LCA) and Data Envelopment Analysis (DEA) was applied to the Peruvian anchoveta fleet. More specifically, a modified 5-step LCA + DEA method, whose particularities are broadly discussed throughout the study, was computed to obtain the desired operational benchmarks and, thereafter, estimate the target environmental gains. Results led to an average efficiency score of 86% throughout the segments, with a total of eight fleet segments out of 13 (62%) operating inefficiently. Nevertheless, no clear pattern was identified through the segments, although certain correlations with stock abundance, fuel use intensity, overcapacity and climatic conditions are discussed. Reduction in material inputs based on operational benchmarks translated into environmental gains that ranged from 26% to 53% for inefficient segments. Finally, it is expected that the findings in this study may aid stakeholders and policy makers when revising fuel use optimisation and overcapacity management strategies.
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ISSN 0959-6526 ISBN Médium
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Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 1146
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Auteur (up) Avarre, J.-C.; Guinand, B.; Dugué, R.; Cosson, J.; Legendre, M.; Panfili, J.; Durand, J.-D.
Titre Plasticity of gene expression according to salinity in the testis of broodstock and F1 black-chinned tilapia, Sarotherodon melanotheron heudelotii Type Article scientifique
Année 2014 Publication Revue Abrégée PeerJ
Volume 2 Numéro Pages
Mots-Clés Acclimation; fish; Gene expression; Male reproduction; salinity
Résumé The black-chinned tilapia Sarotherodon melanotheron heudelotii Rüppell 1852 (Teleostei, Cichlidae) displays remarkable acclimation capacities. When exposed to drastic changes of salinity, which can be the case in its natural habitat, it develops quick physiological responses and keeps reproducing. The present study focused on the physiological impact of salinity on male reproductive capacities, using gene expression as a proxy of acclimation process. Two series of experimental fish were investigated: the first one was composed of fish maintained in freshwater for several generations and newly acclimated to salinities of 35 and 70, whereas the second one consisted of the descendants of the latter born and were raised under their native salinity. Expression patterns of 43 candidate genes previously identified from the testes of wild males was investigated in the three salinities and two generations. Twenty of them showed significant expression differences between salinities, and their predicted function revealed that most of them are involved in the osmotic tolerance of sperm cells and/or in the maintenance of sperm motility. A high level of expression variation was evidenced, especially for fish maintained in freshwater. In spite of this, gene expression patterns allowed the differentiation between fish raised in freshwater and those maintained in hypersaline water in both generations. Altogether, the results presented here suggest that this high variability of expression is likely to ensure the reproductive success of this species under varying salinities.
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ISSN 2167-8359 ISBN Médium
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Numéro d'Appel MARBEC @ alain.herve @ collection 1159
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Auteur (up) Ban, N.C.; Maxwell, S.M.; Dunn, D.C.; Hobday, A.J.; Bax, N.J.; Ardron, J.; Gjerde, K.M.; Game, E.T.; Devillers, R.; Kaplan, D.M.; Dunstan, P.K.; Halpin, P.N.; Pressey, R.L.
Titre Better integration of sectoral planning and management approaches for the interlinked ecology of the open oceans Type Article scientifique
Année 2014 Publication Revue Abrégée Marine Policy
Volume Numéro Pages
Mots-Clés Areas beyond national jurisdiction; Benthic-pelagic interlinkages; High seas; marine conservation; Marine Protected Areas; sustainable fisheries
Résumé Open oceans are one of the least protected, least studied and most inadequately managed ecosystems on Earth. Three themes were investigated that differentiate the open ocean (areas beyond national jurisdiction and deep area within exclusive economic zones) from other realms and must be considered when developing planning and management options: ecosystem interactions, especially between benthic and pelagic systems; potential effects of human activities in open oceans on ecological linkages; and policy context and options. A number of key ecological factors differentiate open oceans from coastal systems for planners and managers: (1) many species are widely distributed and, especially for those at higher trophic levels, wide ranging; (2) the sizes and boundaries of biogeographical domains (patterns of co-occurrence of species, habitats and ecosystem processes) vary significantly by depth; (3) habitat types exhibit a wide range of stabilities, from ephemeral (e.g., surface frontal systems) to hyper-stable (e.g., deep sea); and (4) vertical and horizontal linkages are prevalent. Together, these ecological attributes point to interconnectedness between open ocean habitats across large spatial scales. Indeed, human activities – especially fishing, shipping, and potentially deep-sea mining and oil and gas extraction – have effects far beyond the parts of the ocean in which they operate. While managing open oceans in an integrated fashion will be challenging, the ecological characteristics of the system demand it. A promising avenue forward is to integrate aspects of marine spatial planning (MSP), systematic conservation planning (SCP), and adaptive management. These three approaches to planning and management need to be integrated to meet the unique needs of open ocean systems, with MSP providing the means to meet a diversity of stakeholder needs, SCP providing the structured process to determine and prioritise those needs and appropriate responses, and adaptive management providing rigorous monitoring and evaluation to determine whether actions or their modifications meet both ecological and defined stakeholder needs. The flexibility of MSP will be enhanced by the systematic approach of SCP, while the rigorous monitoring of adaptive management will enable continued improvement as new information becomes available and further experience is gained.
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ISSN 0308-597x ISBN Médium
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Numéro d'Appel LL @ pixluser @ collection 317
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Auteur (up) BAUER, R.; Graewe, U.; Stepputtis, D.; Zimmermann, C.; Hammer, C.
Titre Identifying the location and importance of spawning sites of Western Baltic herring using a particle backtracking model Type Article scientifique
Année 2014 Publication Revue Abrégée Ices Journal Of Marine Science
Volume 71 Numéro 3 Pages 499-509
Mots-Clés backtracking; Baltic Sea; Clupea harengus; hatching sites; lagoon; larval transport; spring spawning
Résumé The recruitment success of some herring stocks fluctuates strongly, and apparently, success is often already determined during the early life stages, i.e. before metamorphosis. In studying the survival of early life stages and its affecting factors, particularly those during the egg stage, it is crucial to examine the processes at the spawning sites, which often cannot be explored directly. A recent decline in the recruitment of Western Baltic spring-spawning herring (WBSSH) increases the urgency of filling the knowledge gap for this stock, especially because one bottleneck in the recruitment seems to occur before hatching. We examined the successful 20032009 spawning sites of WBSSH in the main spawning ground, the Greifswalder Bodden lagoon. Instead of using common techniques such as diving or underwater videography, which are usually unsuitable for mapping large areas, we applied a model approach. We tracked herring larvae at length 610 mm, recorded by larval surveys during MarchJune of the respective years, back to their hatching sites using a Lagrangian particle backtracking model. We compared the spawning areas identified by the model with the results of earlier field studies; however, we also analysed variations between years, larval length groups, and different applied growth models, which are needed to define hatch-dates. Although spawning sites could not be identified with high precision because of the strong diffusion in the area studied, results indicate that larvae up to 10 mm length are caught near their hatching sites. However, the location of successful spawning sites varied largely between years, with the main hatching sites situated in the Strelasund and the eastern entrance of the lagoon. This may reflect variations in spawning-site selection or quality. A better knowledge of the locations and relative importance of, and the processes occurring on, the different spawning sites will provide an important contribution to the sustainable management of this commercially valuable herring stock.
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Volume de collection Numéro de collection Edition
ISSN 1054-3139 ISBN Médium
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Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 1136
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Auteur (up) BECHELER, R.; BENKARA, E.; MOALIC, Y.; HILY, C.; ARNAUD-HAOND, S.
Titre Scaling of processes shaping the clonal dynamics and genetic mosaic of seagrasses through temporal genetic monitoring Type Article scientifique
Année 2014 Publication Revue Abrégée Heredity
Volume 112 Numéro 2 Pages 114-121
Mots-Clés clonality; Seagrass; spatio-temporal genetic structure; Zostera marina
Résumé Theoretically, the dynamics of clonal and genetic diversities of clonal plant populations are strongly influenced by the competition among clones and rate of seedling recruitment, but little empirical assessment has been made of such dynamics through temporal genetic surveys. We aimed to quantify 3 years of evolution in the clonal and genetic composition of Zostera marina meadows, comparing parameters describing clonal architecture and genetic diversity at nine microsatellite markers. Variations in clonal structure revealed a decrease in the evenness of ramet distribution among genets. This illustrates the increasing dominance of some clonal lineages (multilocus lineages, MLLs) in populations. Despite the persistence of these MLLs over time, genetic differentiation was much stronger in time than in space, at the local scale. Contrastingly with the short-term evolution of clonal architecture, the patterns of genetic structure and genetic diversity sensu stricto (that is, heterozygosity and allelic richness) were stable in time. These results suggest the coexistence of (i) a fine grained (at the scale of a 20 x 30 m quadrat) stable core of persistent genets originating from an initial seedling recruitment and developing spatial dominance through clonal elongation; and (ii) a local (at the scale of the meadow) pool of transient genets subjected to annual turnover. This simultaneous occurrence of initial and repeated recruitment strategies highlights the different spatial scales at which distinct evolutionary drivers and mating systems (clonal competition, clonal growth, propagule dispersal and so on) operate to shape the dynamics of populations and the evolution of polymorphism in space and time.
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Volume de collection Numéro de collection Edition
ISSN 0018-067x ISBN Médium
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Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 1139
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