The Growth Response of Two Diatom Species to Atmospheric Dust from the Last Glacial Maximum ...

• Main Authors: Conway, TM, Hoffmann, LJ, Breitbarth, E, Strzepek, RF, Wolff, EW
• Format: Article in Journal/Newspaper
• Language: English
• Published: Public Library of Science 2016
• Subjects: Antarctic Regions; Atmosphere; Carbon; Carbon Dioxide; Chlorophyll; Chlorophyll A; Diatoms; Dust; Ecosystem; Ice; Iron; Nitrates; Nitrogen; Oceans and Seas; Photosynthesis; Phytoplankton; Seawater; Silicon; Antarctic; Southern Ocean; The Antarctic; Antarc*; Antarctica; E. Antarctica; EPICA; ice core
• Online Access: https://dx.doi.org/10.17863/cam.4892; https://www.repository.cam.ac.uk/handle/1810/260659

Relief of iron (Fe) limitation in the surface Southern Ocean has been suggested as one driver of the regular glacial-interglacial cycles in atmospheric carbon dioxide (CO$_2$). The proposed cause is enhanced deposition of Fe-bearing atmospheric dust to the oceans during glacial intervals, with consequent effects on export production and the carbon cycle. However, understanding the role of enhanced atmospheric Fe supply in biogeochemical cycles is limited by knowledge of the fluxes and 'bioavailability' of atmospheric Fe during glacial intervals. Here, we assess the effect of Fe fertilization by dust, dry-extracted from the Last Glacial Maximum portion of the EPICA Dome C Antarctic ice core, on the Antarctic diatom species $\textit{Eucampia antarctica}$ and $\textit{Proboscia inermis}$. Both species showed strong but differing reactions to dust addition. $\textit{E. antarctica}$ increased cell number (3880 vs.786 cells mL$^{-1}$), chlorophyll a (51 vs. 3.9 μg mL$^{-1}$) and particulate organic carbon (POC; ...