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Rigolet, Carinne; Thiebaut, Eric; Dubois, Stanislas. |
Stable carbon and nitrogen isotopic composition (delta C-13 and delta N-15) of benthic organisms was investigated to understand the effects of a gregarious tubicolous amphipod species (Haploops nirae) on benthic food web structures and test whether drastic changes in species composition cause changes in food web structure. The habitat engineered by this species was sampled and compared with the adjacent uncolonized Amphiura filiformis muddy habitat in winter and summer. The isotopic signatures of macrofaunal and megafaunal species associated with both habitats were analysed along with potential food sources at each sampling period. Similar food web structures for each habitat (and each season), with high delta N-15 ranges spanning over 3 trophic levels,... |
Tipo: Text |
Palavras-chave: Stable isotopes; Gregarious amphipod; Source contribution; Haploops; Benthic diatoms; Navicula. |
Ano: 2014 |
URL: https://archimer.ifremer.fr/doc/00187/29822/28259.pdf |
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Champilou, Jean-baptiste; Baltzer, Agnes; Murat, Anne; Reynaud, Marine; Maillet, Grégoire M.; Nardelli, Maria Pia; Metzger, Édouard. |
In the shallow waters of the Bay of Concarneau (South Brittany, France), previous studies reported a dense settlement of the species Haploops (tube-dwelling bioengineer amphipod) that perfectly overlaps a field of pockmarks. A possible mechanistic link may therefore exist between the Haploops colonies and the shallow pockmarks. To test this hypothesis, interferometry sonar and sub-bottom profiler chirp data were acquired in two new areas located in the marine estuary of the Loire River, “La Lambarde” and “Le Croisic”. The new sites share the same sedimentary and geological characteristics as those found in the Bay of Concarneau. The three sites are similarly located in shallow and muddy environments above a faulted Middle Eocene formation that is incised... |
Tipo: Text |
Palavras-chave: Shallow waters; South Brittany (France); Geophysics; Pockmarks; Haploops. |
Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00502/61324/64896.pdf |
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Dubois, Stanislas; Derian, Francois; Caisey, Xavier; Rigolet, Carinne; Caprais, Jean-claude; Thiebaut, Eric. |
We used existing bathymetric data to study the macrofauna of a geophysical pockmark field restricted to a benthic habitat engineered by the tubiculous amphipod Haploops nirae in South Brittany (France). Stations inside and outside pockmarks of different morphometric characteristics (location, size, depression depth) were sampled for macrofauna and environmental parameters (sediment characteristics, organic matter, chl a, hydrogen sulfide and methane concentrations). Diversity indices showed higher species richness inside pockmarks, especially for species with medium to high abundances. Most sediment cores showed low methane but high hydrogen sulfide concentrations. We hypothesised that after eruption, the remaining residual methane from pockmark sediments... |
Tipo: Text |
Palavras-chave: Benthic habitat; Biodiversity; Succession; Amphipod; Haploops; South Brittany; Sulfide; Methane; Environmental factors. |
Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00272/38333/36576.pdf |
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