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Le Bourg, Baptiste. |
Like in the rest of the world, climate change impacts the Southern Ocean, but not in the same way in all regions of this ocean. Changes in sea ice cover around the Antarctic continent are one of the most visible manifestations. For example, sea ice cover has decreased significantly in the Western Antarctic Peninsula while it tends to increase slightly on the rest of the coastline of the continent. These changes in environmental conditions influence the functioning of the ecosystems of this ocean. In particular, the disappearance or persistence of sea ice in a region where it was seasonally present may prevent the appearance of summer phytoplankton blooms, thus impacting the dynamics of krill populations and their predators in the pelagic environment. The... |
Tipo: Text |
Palavras-chave: Sea stars; Southern Ocean; Trophic ecology; Stable isotopes. |
Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00633/74468/74296.pdf |
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Le Bourg, Baptiste; Lepoint, Gilles; Michel, Loic. |
Rationale Stable isotope analysis is used to investigate the trophic ecology of organisms and, in order to use samples from archived collections, and it is important to know whether preservation methods alter the results. This study investigates the long‐term effects of four preservation methods on sea stars isotopic composition and isotopic niche parameters. Methods We assessed effects of preservation method (freezing, drying, formaldehyde, ethanol) and duration (0, 1, 3, 6, 9, 12 and 24 months) on the stable isotope ratios of carbon, nitrogen and sulfur of sea star tissues. Isotopic ratios were measured using CF‐EA‐IRMS. We also monitored the evolution of commonly used ecological metrics (isotopic niche parameters) throughout the experiment. Results... |
Tipo: Text |
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Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00514/62533/66862.pdf |
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Brosset, Pablo; Le Bourg, Baptiste; Costalago, David; Banaru, Daniela; Van Beveren, Elisabeth; Bourdeix, Jean-herve; Fromentin, Jean-marc; Menard, Frederic; Saraux, Claire. |
Since 2008, a severe decrease in size and body condition together with a demographic truncation has been observed in the sardine (secondarily in anchovy) population of the Gulf of Lions (NW Mediterranean Sea). In parallel, sprat biomass, which was negligible before, has increased tenfold. All of these changes have strongly affected the regional fisheries. Using trophic and isotopic data from contrasting periods of low versus high growth and condition, we investigated potential changes in diet and interspecific feeding interactions through time. Evidence of resource partitioning was found between sprat and both anchovy and sardine in 2004 and 2005. Since 2010, the isotopic niches of the 3 species have tended to overlap, suggesting higher risk of competition... |
Tipo: Text |
Palavras-chave: Trophic ecology; Anchovy; Sardine; Sprat; Dietary overlap; NW Mediterranean. |
Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00347/45822/45540.pdf |
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