Évaluation de la continuité écologique pour la truite de mer sur la Mauldre, un affluent de la Seine
Master Lotic terrestrial aquatic ecosystems, which give shelter to a huge biodiversity, aresensitive to anthropogenic threat (intensive agricultural and industrial activities, urbanization,development of watercourses). These activities can lead to an alteration in the physico-chemicalquality, the hy...
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| Other Authors: | , , , |
| Format: | Master Thesis |
| Language: | French |
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HAL CCSD
2021
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| Subjects: | |
| Online Access: | https://hal.inrae.fr/hal-04192909 https://hal.inrae.fr/hal-04192909/document https://hal.inrae.fr/hal-04192909/file/Rapport_de_stage_Romain_Guittet-Chaleux_M2_BEE_Saclay_Menu_CONS.pdf |
| Summary: | Master Lotic terrestrial aquatic ecosystems, which give shelter to a huge biodiversity, aresensitive to anthropogenic threat (intensive agricultural and industrial activities, urbanization,development of watercourses). These activities can lead to an alteration in the physico-chemicalquality, the hydrological regimes and the morphology of watercourses and induce a loss ofecological continuity within the hydrographic network. Diadromous fish are particularlyvulnerable species, due to their life cycle requiring migrations from marine waters tofreshwaters. Historically, the Seine basin had ten species of diadromous fish. Navigationdevelopment and pollution of the waters of the basin led to the loss of some historically presentspecies in the 70s, like the Atlantic salmon. Today, thanks to the efforts made, certain speciesare gradually recolonizing the basin. This study focuses on the specific case of sea trout on ariver tributary to the Seine that is heavily anthropized: the Mauldre. The objectives of the studyare to locate the presence of potential spawning grounds on the watercourse and to assess theiraccessibility through ecological continuity modeling using the least cost path analysis. Theimpact of the main barriers to migration has been assessed. The hydraulic barriers, that aredisturbing fish life movements, and physico-chemical pollution have been identified. Thescenarios for the gradual erasure of hydraulic obstacles from downstream water to upstreamwater, as well as the scenarios of improving water quality, have highlighted the actions to targetto restore ecological continuity and allow the recolonization of sea trout, a species indicator ofthe good conditions of freshwater streams. Les écosystèmes aquatiques terrestres lotiques sont des milieux particulièrementsensibles aux activités anthropiques (activités agricoles intensives et industrielles, urbanisation,aménagement des cours d'eau, etc.). Ces activités peuvent conduire à une altération de la qualitéphysico-chimique, des régimes hydrologiques et ... |
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