Consulta: subjectFacets:"Delta N-15"
Registros recuperados: 3
Data/hora: 27/07/2024 02:23:05

Deglacial-Holocene environmental changes at the Pacific entrance of the Strait of Magellan
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Harada, Naomi; Ninnemann, Ulysses; Lange, Carina B.; Marchant, Margarita E.; Sato, Miyako; Ahagon, Naokazu; Pantoja, Silvio.
We show environmental and nitrogen cycle changes between 13 and 2.5 kyr BP (from the latest deglaciation to the Holocene) based on biogeochemical records in a sediment core from the Pacific entrance of the Strait of Magellan. Organic carbon, total nitrogen, and C-37 alkenone contents were low during 13-9 kyr BP but increased rapidly at 8 kyr BP. The relative contribution of tetra-unsaturated C-37 alkenone, used as a salinity proxy, suggests low salinity during 13-9 kyr BP changing to high salinity at 8 kyr BP. Planktic foraminifer data showed that Globigerina bulloides was more abundant during the deglacial-early Holocene than in the mid-late Holocene, whereas abundances of Neogloboquadrina pachyderma showed the opposite pattern. This evidence plus...
Tipo: Text
Palavras-chave: Biogenic components; Delta C-13; Delta N-15; Planktic foraminifera; Alkenone; Sea surface temperature; Southern Patagonia.
Ano: 2013
URL: https://archimer.ifremer.fr/doc/00264/37548/36825.pdf

Effects of alga Fucus serratus decline on benthic assemblages and trophic linkages at its retreating southern range edge
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Duarte, Linney; Rossi, Francesca; Docal, Cristina; Viejo, Rosa M.
Canopy-forming seaweeds are important coastal ecosystem engineers that sustain diverse multi-trophic assemblages. Their losses, with the subsequent reduction in habitat complexity, have been documented across many parts of the world and are often attributed to climate change and other anthropogenic factors. The general aim of the present study was to understand the repercussions of the decline of the canopy-forming alga Fucus serratus L. at its retreating southern range edge in the diversity and food-web linkages of intertidal assemblages. Few studies have attempted to document changes in benthic food webs following canopy loss. We examined the differences among southern locations situated at different distances from the range margin: those at the very...
Tipo: Text
Palavras-chave: Canopy-forming algae; Fucus serratus; Rear range edge margin; Delta N-15; Delta C-13; Stable isotope analysis; Food web.
Ano: 2015
URL: https://archimer.ifremer.fr/doc/00626/73845/73611.pdf

Seasonal variation of stable isotope ratios of size-fractionated zooplankton in the Bay of Marseille (NW Mediterranean Sea)
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Banaru, Daniela; Carlotti, Francois; Barani, Aude; Gregori, Gerald; Neffati, Nada; Harmelin-vivien, Mireille.
Stable isotope ratios of six size fractions of zooplankton (80 to &gt;2000 mm) were analyzed seasonally in 2009-2010 at the SOMLIT site in the Bay of Marseille. Isotopic ratios generally increased with zooplankton size. The highest delta N-15 values were observed in the 1000-2000 mm fraction. The largest size class (&gt;2000 mu m), dominated by gelatinous plankton, had lower delta N-15 values due to the low isotopic signatures of most of these organisms. In the larger size fractions (&gt;1000 mu m), isotopic ratios were measured at the taxon level. Brachyuran, stomatopod, teleost and cephalopod larvae showed the highest delta N-15 values, and salps and pteropods the lowest ones. Lower values of both delta C-13 and delta N-15 were recorded in winter and...
Tipo: Text
Palavras-chave: Plankton; Delta C-13; Delta N-15; Size classes; Flow cytometry.
Ano: 2014
URL: https://archimer.ifremer.fr/doc/00372/48275/48536.pdf