|
|
|
|
|
Stachowski-haberkorn, Sabine; Quiniou, Louis; Beker, Beatriz; Haberkorn, Hansy; Marie, Dominique; De La Broise, Denis. |
The impacts of the fungicide Opus(A (R)) (epoxiconazole) on marine phytoplankton communities were assessed in a 12-day field experiment using in situ microcosms maintained underwater at 6 m depth. Three community analysis methods were compared for their sensitivity threshold in fungicide impact detection. When phytoplankton communities were exposed to 1 mu g l(-1) of epoxiconazole, no effects could be demonstrated using TTGE (Temporal Temperature Gradient gel Electrophoresis), flow cytometry or HPLC. When exposed to 10 mu g l(-1), TTGE fingerprints from PCR amplified 18S rDNA of communities exhibited significant differences compared with controls (ANOSIM, P = 0.028). Neither flow cytometry counts, nor HPLC pigment profiles allowed to show significant... |
Tipo: Text |
Palavras-chave: Microcosm; Phytoplankton community; Epoxiconazole; TTGE; Flow cytometry; HPLC. |
Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/00088/19888/17547.pdf |
| |
|
|
Stachowski-haberkorn, Sabine; Becker, Beatriz; Marie, Dominique; Haberkorn, Hansy; Coroller, Louis; De La Broise, Denis. |
The effects of the herbicide Roundup (R) (glyphosate) on natural marine microbial communities were assessed in a 7-day field experiment using microcosms. Bottles were maintained underwater at 6 m depth, and 10% of their water content was changed every other day. The comparison of control microcosms and surrounding surface water showed that the microcosm system tested here can be considered as representative of the natural surrounding environment. A temporal temperature gradient gel electrophoresis (TTGE) was run on 165 and 18S rDNA-amplified extracts from the whole microbial community. Cluster analysis of the 16S gel showed differences between control and treatment fingerprints for Roundup at 1 mu g L-1 (ANOSIM,p=0.055; R=0.53), and 10 mu g L-1 (ANOSIM,... |
Tipo: Text |
Palavras-chave: Microcosm; Marine microbial communities; Glyphosate; TTGE; Flow cytometry. |
Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/00088/19887/17546.pdf |
| |
|
|
Giraud, Mélanie; Garçon, Véronique; De La Broise, Denis; L'Helguen, Stéphane; Sudre, Joël; Boye, Marie. |
Installation of an Ocean Thermal Energy Conversion pilot plant (OTEC) off the Caribbean coast of Martinique is expected to use approximately 100,000 m3 h−1 of deep seawater for its functioning. This study examined the potential effects of the cold nutrient-rich deep seawater discharge on the phytoplankton community living in the surface warm oligotrophic waters before the installation of the pilot plant. Numerical simulations of deep seawater upwelled by the OTEC, showed that a 3.0 °C temperature change, considered as a critical threshold for temperature impact, was never reached during an annual cycle on the top 150 m of the water column on two considered sections centered on the OTEC. The thermal effect should be limited, <1 km2 on the area exhibited... |
Tipo: Text |
Palavras-chave: Marine microbial ecosystem; Biogeochemistry; Modeling; Artificial seawater discharge in situ experiments; Environmental standards. |
Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00507/61867/65935.pdf |
| |
|
|
De La Broise, Denis; Stachowski-haberkorn, Sabine. |
Microcosms, each consisting of 2 L natural surface seawater maintained in 2.3-L glass bottles, were immersed at a depth of 6 metres. The renewal of ten percent of microcosm volumes was carried out every other day. Phytoplankton-containing seawater was used for renewal (previously filtered through 25-, 50- or 200-μm cut-off). Phytoplankton community pigment analysis (by HPLC) and flow cytometry analysis were performed. After 13 days, data exhibited phytoplankton characteristics in microcosms in the same range as that of the natural surrounding sea water over the same period. Furthermore, in these microcosms, a negative correlation was observed between the filtration cut-off used for renewal water, and the eukaryote cell count. Herbicides were tested as... |
Tipo: Text |
Palavras-chave: Phytoplankton; Microcosm; Herbicides; Dimethenamid; Bentazon. |
Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00088/19889/17548.pdf |
| |
|
|
|