Logo Universitat Bremen
 
Seitenpfad:

Elinor Tessin

Doktorand_innen

Gruppe: 

Mikropaläontologie - Paläozeanographie

E-Mail:

Raum: 

MARUM II, 1050

Elinor Tessin

PhD Project

Resolving the molecular structure of dinoflagellate cyst walls

A large portion of global primary production takes place in the surface layers of the ocean. Here, CO2 is fixed into organic matter, which is then transformed or transported laterally or downward through the water column. Only a small portion of this material reaches and is then stored at the ocean floor.

Within the Cluster of Excellence “The Ocean Floor – Earth’s Uncharted Interface”, the RECEIVER Research unit studies this transfer of matter to the ocean floor. Theme 3 of this unit, “The transfer of matter and signals into the ocean floor” is focused on improving our understanding of how such organic matter is altered on its way into and within oceanic sediments.

One such group of organic matter are the organic-walled cysts of dinoflagellates (dinocysts). As polysaccharide-based particles that can easily be traced back to their biological source, dinocysts from ocean sediments can be used as proxies to study past climatic conditions. This requires that the production and subsequent alteration of both the proxy signal and proxy signal carrier are well understood. Historically, dinocysts were believed to be extremely resistant to aerobic degradation, but it has been repeatedly shown that some cyst species are far more resistant than others.

Selective preservation of dinocysts is a potential bias in paleoclimate studies and models of CO2 storage, but also opens up new perspectives of using species of varying recalcitrance as finely tuned markers of deep ocean ventilation and aerobic degradation of organic matter in marine sediments. It will first be necessary to achieve a more complete understanding of the molecular characteristics that make species labile or recalcitrant.

The aim of this project is to analyze the cell wall structure of known labile and recalcitrant cysts. I aim to resolve the following questions:

  1. How does molecular structure differ between different species? If such differences exist, Micro-FTIR spectra could be a viable alternative to dinocyst species identification relying on genetic sequencing or morphological characteristics.
  2. To what extent is the molecular structure of resistant dinocysts altered by diagenetic processes?
  3. How does the molecular structure of cysts of each species differ between regions?
Cysts of Impagidinium aculeatum

Previous Re­se­arch Pro­jects

Master Thesis Drivers of spatial variability in spring bloom onset and magnitude along a latitudinal gradient in the Nordic Seas University of Bergen, University Centre in Svalbard
Bachelor Thesis   

Identifying patterns in bat movement capabilities through literature review and R analysis

University of Konstanz, Max Planck Institute for Ornithology