Controls on and paleoceanographic utility of the valve size frequency distribution of the Southern Ocean diatom, Fragilariopsis kerguelensis

• Antragstellerin: Dr. Christina de la Rocha
• Fachliche Zuordnung: Physik, Chemie und Biologie des Meeres
• Förderung: Förderung von 2008 bis 2015
• Projektkennung: Deutsche Forschungsgemeinschaft (DFG) - Projektnummer 75446113

Unraveling the role of the Southern Ocean's biological pump in regulating climate would be enhanced by the development of paleoceanographic proxies specific to carbon or silica cycling. Observations that the average size of valves of the diatom, Fragilariopsis kerguelensis, varies seasonally, with latitude, and over glacial-interglacial cycles in the Southern Ocean suggest that the valve size frequency distribution in sediments could be used to reconstruct aspects of paleoproductivity and silica cycling. We aim to develop this proxy by using culture, field and sediment samples to determine the exact controls on valve size frequency distributions, the most important of which is likely to be the frequency of auxospore formation within the population. The controls on auxospore formation are as yet unknown and both mating experiments in culture as well as in situ iron fertilization experiments are likely to unravel the mechanisms determining auxospore formation under both controlled and field conditions. The valve size frequency distribution can then be used to indicate the intensity of the environmental and/or biological conditions triggering auxospore formation.

• DFG-Verfahren: Infrastruktur-Schwerpunktprogramme
• Teilprojekt zu: SPP 1158: Bereich Infrastruktur - Antarktisforschung mit vergleichenden Untersuchungen in arktischen Eisgebieten
• Beteiligte Personen: Dr. Philipp Assmy; Dr. Giuseppe Cortese; Professor Dr. Victor Smetacek