The effect of population dynamics, growth and calcification of planktonic foraminifera on the pelagic carbonate flux

• Main Author: Kiss, Peter
• Other Authors: Hudáčková, Natália, Kučera, Michal
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: Universität Bremen 2021
• Subjects: planktonic foraminifera; carbon cycle; sediment trap time series; Pleistocene; Miocene; 550; 550 Earth sciences and geology; ddc:550; Planktonic foraminifera
• Online Access: https://media.suub.uni-bremen.de/handle/elib/5701; https://doi.org/10.26092/elib/1380; https://nbn-resolving.org/urn:nbn:de:gbv:46-elib57013

The planktonic foraminifera calcite production represents a fundamental component of the pelagic carbon cycle by contributing up to half of the biogenic carbonate export flux to the deep ocean, whilst simultaneously the calcite biomineralisation releases CO2 from the surface waters. Due to its relevance for the pelagic carbonate budget and the biological pump, in terms of oceanic capacity of CO2 sequestration from the atmosphere, it is crucial to understand the mechanisms constraining the short-term (intra-and interannual) and long-term (centennial to millennial) variability in the planktonic foraminifera calcite flux. The planktonic foraminifera calcite flux is the product of the species individual calcite fluxes where variability in calcite flux can be caused by changes in the species i) individual flux, ii) shell size, and iii) calcification intensity. In the exported assemblages, where size and calcification intensity vary among the species, changes can be caused by the species composition as well. Previous research has not investigated these three mechanisms comprehensively in the context of the planktonic foraminifera calcite flux. Thus, it is uncertain how many of the potential controlling mechanisms are sufficient to be considered to constrain the variability in the planktonic foraminifera calcite flux and to derive an accurate planktonic foraminifera calcite budget. To assess the importance of these mechanisms in regulating the short-term variability in planktonic foraminifera calcite flux, record of species-resolved shell flux, shell size, and calcification intensity variations during two years of sedimentation (from 1990-1991 and 2007-2008) from the Cape Blanc upwelling area in the Atlantic Ocean was generated. In order to compare how the short-term variability in the regulating mechanisms compares to long-term trends and to assess how these mechanisms responded to large amplitude environmental changes, we investigated exceptionally preserved planktonic foraminifera communities from a well-dated ...