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| Taormina, Bastien; Bald, Juan; Want, Andrew; Thouzeau, Gerard; Lejart, Morgane; Desroy, Nicolas; Carlier, Antoine. |
| Submarine power cables (SPC) have been in use since the mid-19th century, but environmental concerns about them are much more recent. With the development of marine renewable energy technologies, it is vital to understand their potential impacts. The commissioning of SPC may temporarily or permanently impact the marine environment through habitat damage or loss, noise, chemical pollution, heat and electromagnetic field emissions, risk of entanglement, introduction of artificial substrates, and the creation of reserve effects. While growing numbers of scientific publications focus on impacts of the marine energy harnessing devices, data on impacts of associated power connections such as SPC are scarce and knowledge gaps persist. The present study (1)... |
| Tipo: Text |
Palavras-chave: Submarine power cables; Marine renewable energy; Environmental impacts; Ecosystem functioning; Benthic habitats. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00454/56542/58330.pdf |
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| Aschenbroich, Adelaide; Michaud, Emma; Stieglitz, Thomas; Fromard, Francois; Gardel, Antoine; Tavares, Marcos; Thouzeau, Gerard. |
| This study in French Guiana evaluates the changes of crab assemblages and their bioturbation activities between mangrove early stages (pioneer and young mangrove) and within stages by taking their spatial heterogeneity (tidal channels, flat areas, pools) into account. The results show differences in crab assemblage structure between and within the early stages of mangrove in relation to microhabitat and sediment characteristics. The sediment reworking rates are a function of the biomass or density of particular species (Ucides cordatus, Uca cumulanta) and burrower functional groups. Crab species or functional interaction mediate changes in sediment reworking rates suggesting the need to consider entire benthic communities rather than single species. This... |
| Tipo: Text |
Palavras-chave: Mangroves; Crabs; Community composition; Bioturbation; French Guiana; Amazon. |
| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00350/46154/45852.pdf |
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| Aguirre-velarde, Arturo; Thouzeau, Gerard; Jean, Frederic; Mendo, Jaime; Cueto-vega, Rosa; Kawazo-delgado, Midori; Vásquez-spencer, Jazmín; Herrera-sanchez, Diego; Vega-espinoza, Alex; Flye-sainte-marie, Jonathan. |
| The response of Argopecten purpuratus (Peruvian scallop) to environmental conditions was studied in the upwelling-influenced Bay of Paracas (Peru). Scallops growth and reproduction were monitored weekly over a 7-month period under two conditions (culture depths): on the bottom and 2 m above (suspended culture). At the same time, a high-frequency environmental monitoring was realized at the aforementioned depths. The results indicate that environmental conditions in the Bay are highly variable, especially during the summer: temperature fluctuations up to 8∘C were recorded in less than one day while oxic conditions ranged from oversaturation to anoxia. Milky-turquoise waters discoloration events (sulphide presence suspected) were simultaneously observed... |
| Tipo: Text |
Palavras-chave: Argopecten purpuratus; High frequency monitoring; Coastal upwelling; Hypoxic/anoxic conditions; Growth; Reproduction; Aquaculture; Milky-turquoise water/aguas Blancas. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00504/61547/65430.pdf |
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| Thouzeau, Gerard. |
| L'étude de l' écologie des post-larves et des juvéniles de Pecten maximus (L . ) en baie de Saint-Brieuc (France), s' inscrit dans le cadre du Proqramme National sur le Déterminisme du Recrutement ( P.N.D.R .) de l'espèce, engagè par l'I.F.R.E.M.E.R. depuis 1985. La variabilité spatio- temporelle intra- et interannuelle de la distribution, de la survie , et de la croissance des pré-recrues de coquille Saint-Jacques, ainsi que la caractérisation de la niche trophique,occupée par l'espèce, font l'objet du présent manuscrit. L'existence du P.N.D.R . Coquille Saint-Jacques est motivée par l' état du gisement briochin : si ce dernier constituait dans les années soixante-dix le premier gisement producteur des côtes françaises (tant en valeur absolue qu'en... |
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| Ano: 1989 |
URL: http://archimer.ifremer.fr/doc/00450/56182/57737.pdf |
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| Deborde, Jonathan; Abrill, Gwenael; Mouret, Aurelia; Jezequel, Didier; Thouzeau, Gerard; Clavier, Jacques; Bachelet, Guy; Anschutz, Pierre. |
| A study was conducted in Arcachon Bay, France, to determine the effect of seasonal dynamics in a Zostera noltii meadow on P and Fe cycles in the superficial sediments of a tidal mudflat. The redox-sensitive Fe particulate pool and associated P in the root zone showed a seasonal variation following the growth and decay of Z. noltii biomass, with a maximum content during the growth period. In comparison, the bare sediments did not show significant seasonal changes. A dissolved inorganic phosphorus (DIP) uptake was measured from the water column to the sediment in vegetated sediments, whereas a net DIP efflux was observed in the unvegetated sediments. During the growth period, the formation of an iron oxihydroxide-rich zone occurred and acted as a trap for... |
| Tipo: Text |
Palavras-chave: Nutrient; Eelgrass growth; Intertidal zone; Lagoon; Early diagenesis. |
| Ano: 2008 |
URL: https://archimer.ifremer.fr/doc/00603/71539/69966.pdf |
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| Ray, Raghab; Thouzeau, Gerard; Walcker, Romain; Vantrepotte, Vincent; Gleixner, Gerd; Morvan, Sylvain; Devesa, Jeremy; Michaud, Emma. |
| There is growing evidence that a substantial fraction of the dissolved organic and inorganic carbon (DOC and DIC) and particulate organic carbon (POC) can be exported from mangroves to the ocean. Yet our understanding of C fluxes in mangrove forests is limited to only few regional studies that exclude the world's longest sediment dispersal system connected to the Amazon River. The present study aims at (1) examining tidal fluctuations of DOC, POC, and DIC; their isotopes; and optical properties such as chromophoric dissolved organic matter (CDOM) and (2) estimating their exchange fluxes between the mangroves and adjacent coastal water in the Sinnamary estuary, French Guiana. Time series observation highlighted that physical processes coupled to tides... |
| Tipo: Text |
Palavras-chave: Organic matter; Tidal cycle; Carbon flux; Mangroves; French Guiana. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00643/75488/76339.pdf |
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| Cueto‐vega, Rosa; Flye‐sainte‐marie, Jonathan; Aguirre‐velarde, Arturo; Jean, Frederic; Gil‐kodaka, Patricia; Thouzeau, Gerard. |
| During recent years, mass mortalities of cultured scallops became more frequent in Peruvian bays. One of the main drivers related to these mortalities was hypoxic events. This study was designed to understand the hypoxia phenomenon in these bays and to assess how the Peruvian scallop, Argopecten purpuratus, can cope with reduced oxygen levels in seawater based on individual size. First, we analyzed the relationships between dissolved oxygen saturation and other environmental parameters (the Coastal El Niño Index, temperature, salinity and pH) in bottom seawater, the frequency and intensity of hypoxic events in two main culture areas (Sechura and Paracas Bays), and their relationship with scallop mass mortalities. Then, we performed experiments with two... |
| Tipo: Text |
Palavras-chave: Argopecten purpuratus; Lt50; Mass mortality; Severe hypoxia; Size effect. |
| Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00692/80410/83521.pdf |
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| Ragueneau, Olivier; Raimonet, Melanie; Maze, Camille; Coston-guarini, Jennifer; Chauvaud, Laurent; Danto, Anatole; Grall, Jacques; Jean, Frederic; Paulet, Yves-marie; Thouzeau, Gerard. |
| In this contribution, the study of the Bay of Brest ecosystem changes over the past 50 years is used to explore the construction of interdisciplinary knowledge and raise key questions that now need to be tackled at the science-policy-communities interface. The Bay of Brest is subject to a combination of several aspects of global change, including excessive nutrient inputs from watersheds and the proliferation of invasive species. These perturbations strongly interact, affecting positively or negatively the ecosystem functioning, with important impacts on human activities. We first relate a cascade of events over these five decades, linking farming activities, nitrogen, and silicon biogeochemical cycles, hydrodynamics of the Bay, the proliferation of an... |
| Tipo: Text |
Palavras-chave: Sustainability; Land-ocean continuum; Bay of Brest; Interdisciplinarity; Science-policy-community interface. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00616/72792/72272.pdf |
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