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| Merillet, Laurene; Kopp, Dorothee; Robert, Marianne; Salaun, Michele; Mehault, Sonia; Bourillet, Jean-francois; Mouchet, Maud. |
| The development of the vessel monitoring system (VMS) in the recent years has offered high-resolution data to map the distribution and intensity of fishing activities and contributed to enhancing the potential identification of fishing impacts. However, impacts could vary at very small scale and the resolution of VMS data might not be fine enough. Other proxy could be used, such as trawl marks visible on the seabed observed by underwater video or side-scan sonar to evaluate small-scale trawling effort. In the Bay of Biscay, an underwater video survey of the Nephrops norvegicus fishing ground was conducted and provided environmental characteristics such as depth and number of trawl marks at 152 transects. The relevance of observed trawl marks as a... |
| Tipo: Text |
Palavras-chave: Bay of Biscay; Fishing intensity; Sediments; Underwater video; Vessel monitoring system. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00410/52112/52854.pdf |
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| Merillet, Laurene; Kopp, Dorothee; Morandeau, Fabien; Mehault, Sonia; Rimaud, Thomas; Piton, C. |
| In the context of the reform of the Common Fishing Policy (CFP) undertaken by the European Union and implemented since 1st January 2014, the discarding of unwanted catches will gradually be forbidden. Article 15 of the CFP lays down a landing obligation for all species subject to European quotas and will come into force between 2015 and 2019 according to the species and the zones. The Regulation allows several exemptions including one for "species for which scientific proof shows high survival rates, due to the characteristics of the fishing gear, the fishing methods and the ecosystem" (EU Regulation No. 1380/2013). In particular, Nephrops were identified by the International Council for the Exploration of the Sea (ICES) as one of the species having the... |
| Tipo: Text |
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| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00378/48953/49357.pdf |
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| Merillet, Laurene. |
| Marine ecosystems face many pressures, the main ones being fishing and climate change. These pressures do not have the same consequences on the different facets of biodiversity, e.g. on taxa, traits and networks, and their study is necessary for the implementation of an ecosystem approach to fisheries. The Celtic Sea is a very important fishing area for European fisheries, with a specific richness greater than adjacent areas. Based on a time series from 2000 to 2016, I have studied the spatio-temporal dynamics of 101 species of the ecosystem. Over this period, taxonomic biodiversity was stable, and the importance of fishing as a structuring variable for communities decreased after 2009, and was lower than the environment (depth, chlorophyll a concentration... |
| Tipo: Text |
Palavras-chave: Approche écosystémique des pêches; Dynamiques spatio-temporelles; Traits d’histoire de vie; Réseaux trophiques; Gestion des ressources; Ecosystem approach to fisheries; Spatio-temporal dynamics; Community ecology; Life-history traits; Food webs; Resource management. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00666/77806/79980.pdf |
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| Merillet, Laurene; Mehault, Sonia; Rimaud, Thomas; Piton, Corentine; Morandeau, Fabien; Morfin, Marie; Kopp, Dorothee. |
| In the context of the landing obligation set by the new Common Fisheries Policy (CFP), Norway lobster Nephrops norvegicus was identified as a species likely to have high survival rate when discarded in the bottom trawl fishery of the Bay of Biscay. Previous studies in this area reported a survival rate between 30% and 51%, but the experiments were done on a limited monitoring period and the seasonal variations were not investigated. This study was designed to obtain a reliable value for survival rate after a 14-day monitoring period in onshore tanks allowing considering delayed mortality. The study also tested the effect on the survival rate of using a discarding chute system, a sorting device that was made mandatory on the 1st of January 2017 for Nephrops... |
| Tipo: Text |
Palavras-chave: Nephrops norvegicus; Sorting process; Captivity; Vitality; Season; Discard survival. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00407/51864/52608.pdf |
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| Merillet, Laurene; Robert, Marianne; Salaun, Michele; Schuck, Lucie; Mouchet, Maud; Kopp, Dorothee. |
| Based on towed underwater videos, diversity patterns and their main environmental and anthropogenic drivers were assessed in the “Grande Vasière” (northeast Bay of Biscay), one of the main French fishing grounds. The density of bentho-demersal megafauna was recorded along 152 transects in this area in 2014. The highest number of taxa and densities were observed on the external margin of the Grande Vasière, in deep areas with low fishing intensity. The highest levels of taxa evenness were located on the central and coastal parts that are shallower and exposed to medium to high trawling intensity. Multivariate analysis identified four different communities driven by fishing intensity, depth, sediment type and bottom current speed. We distinguished three... |
| Tipo: Text |
Palavras-chave: Biodiversity patterns; Indicator species; Fishing and environmental variables. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00441/55261/56796.pdf |
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| Merillet, Laurene; Mouchet, Maud; Robert, Marianne; Salaun, Michele; Schuck, Lucie; Vaz, Sandrine; Kopp, Dorothee. |
| Trawling activities are considered to be one of the main sources of disturbance to the seabed worldwide. We aimed to disentangle the dominance of environmental variations and trawling intensity in order to explain the distribution of diversity patterns over 152 sampling sites in the French trawl fishing-ground, the Grande Vasière. Using a towed underwater video device, we identified 39 taxa to the finest taxonomic level possible, which were clustered according to their vulnerability to trawling disturbance based on functional traits. Using generalized linear models, we investigated whether the density distribution of each vulnerability group was sensitive to trawling intensity and habitat characteristics. Our analyses revealed a structuring effect of depth... |
| Tipo: Text |
Palavras-chave: Bay of Biscay; Biodiversity; Bottom trawl; Fishing; Underwater video; Vulnerability. |
| Ano: 2018 |
URL: http://archimer.ifremer.fr/doc/00406/51741/52436.pdf |
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