Ecological influences on {delta} 13 C of particulate matter in seasonally ice-covered Ryder Bay, Antarctica
Carbon isotopes may be a useful paleoceanographic tool for reconstructing past p CO2 of surface water, but isotopic composition of particulate organic carbon has been shown in both field and laboratory studies to be affected by p CO2, growth rate, cell size, cell geometry, light availability, carbon...
| Main Authors: | , , , |
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| Format: | Conference Object |
| Language: | unknown |
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US Geological Society and the National Academies
2008
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| Subjects: | |
| Online Access: | https://eprints.gla.ac.uk/5320/ http://pubs.usgs.gov/of/2007/1047/10th_ISAES_Program_book.pdf |
| Summary: | Carbon isotopes may be a useful paleoceanographic tool for reconstructing past p CO2 of surface water, but isotopic composition of particulate organic carbon has been shown in both field and laboratory studies to be affected by p CO2, growth rate, cell size, cell geometry, light availability, carbon metabolism and species composition. To date, field studies have not constrained the dominant factors controlling surface water {delta} 13 C pOC . We present high-resolution time series data from a study in Ryder Bay, Antarctica, which compares seasonal fluctuations in mixed-layer {delta} 13 C pOC with detailed ecological and morphological analysis of phytoplankton communities, community productivity, {delta} 13 C DIC , nutrient dynamics, and hydrographic parameters. Preliminary results indicate that physical processes such as ocean-atmosphere gas exchange and upwelling do not significantly affect {delta} 13 C pOC signatures. In contrast, speciation shifts of diatom assemblages show strong correlation with changes in {delta} 13 C pOC signals, supporting recent suggestions that taxonomic data are necessary for confident interpretation of sedimentary {delta} 13 C records. |
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