Earth Sciences
Welcome to Stellenbosch University

​​​​​​​​​Dr. Susanne Fietzdsc_5725.jpg

Senior Lecturer

Department of Earth Sciences,
Stellenbosch University, South Africa
tel +27-21-808-3117
email: sfietz at

Research theme: Biogeochemistry in aquatic systems, Environmental Geochemistry, Paleoenvironment, Global Change

Research profile:

My research aims to study modern aquatic systems and sedimentary archives as well as sedimentation processes to help interpretation. This approach provides essential information on past and present environmental conditions for those predicting future local and global changes.

We currently have a major ongoing project on the Southern Ocean: Studying biogeochemical cycles to help evaluate potential tools for climate mitigation. Almost all life on Earth depends somehow on photosynthesis fueled by energy from the sun. Growth, which translates into carbon fixation and thus atmospheric CO2 reduction, however, further depends on the availability of macro- and trace nutrients. One of the most famous quotes of early awareness of climate changes and potential mitigation strategies is from John Martin (Moss Landing Marine Laboratories, US, 1988) "Give me half a ship load of iron...I could give you an ice age". In 2013, there is still no scientific consensus, what the consequences of this type of geo-engineering are. We aim to investigate how phytoplankton, acclimatized to current conditions of light and trace metal availability, will most likely respond to predicted future global warming and thus ocean structure changes. 

Other projects with potential for prospective Honours and MSc students:

  • related to paleoenvironmental reconstructions

    • Past climatic changes across continental southern Africa.

    • Past climate and productivity changes in Eurasia.

    • Temperatures and productivity changes in the Southern Ocean coupled to continental air temperatures and hydrological conditions.

    • Upper ocean structure and productivity in the North-East Atlantic.

  • related to proxy calibration for paleoclimate reconstructions

    • Use of bGDGTs (bacterial membrane lipids) for past air temperature reconstructions in southern Africa.

  • related to organic matter production, transport and export

    • Dust transport of molecular sized compounds.

  • related to modern aquatic ecosystem functioning/ Aquatic biogeochemical cycles

    • Environmental monitoring in Lake Baikal.

    • Trace metal impact on phytoplankton photosynthesis and CO2 uptake in the Southern Ocean.

Ongoing or accomplished PhD, MSc and Honours theses at Stellenbosch University:

2021, Liam Quinlan: "Assessing benefits for on-campus phytoplankton pigment analysis"

2021-2022Jayde Bromwhich: "Summer and winter phytoplankton composition in the Atlantic adn Indian sectors of the Southern Ocean"

2021-2022, Emtia Wium: "Impact of potentially toxic trace metals on phytoplankton in waters south of South Africa"​​

2020, Ireland Allisaib: "Natural vs. Anthropogenic dust characteristics and potential impacts"

2019/2020 Sunnette Vos (Uni Pretoria): "Effects of hydrocarbon contamination on virus-host interactions​"

2019, Warrick Daws: "Pollution in Saldanha Bay, Western Cape"​

2019, Herman Boock: "Impact of metal contaminants on marine microorganisms"

2018 + 2019/2020, Raya Stavreva: "Paleo-proxies in sediments of Lake Baikal, Siberia" & "Constraining Barium as paleoproxy"

2016 + 2017/2018 + 2019-2021, Johan Viljoen: “Phytoplankton community composition in the Southern Ocean”

2015 + 2016/2017 + 2018-2020, Ismael Kangueehi: “Composition and impact of Southern African dust”

2018, Sean Househam: "Metal load in water and sediments of False Bay, Western Cape" 

2018, Dylan McLeod: "Nutrient retention in streams of the Western Cape"

2018/2019, Zandria Jordaan: "Driving factors of del13POC in the Atlantic Southern Ocean" 

2018-2020, Asmita Singh: "​​Southern Ocean phytoplankton ecophysiological response to iron availability​" 

2017/2018, Ian Weir: "Testing the Silicate Leakage Hypothesis in the Southern Ocean"

2016 + 2017/2018, Reuben Lazarus: "Urban river pollution in the Western Cape, South Africa"

2017, Jodie Pieterse: "Bacterial and archael community composition in the Atlantic sector of the​ Southern Ocean".

2017, Zahné Pienaar: "changes in deltaC13 across the Southern Ocean and in iron fertilisation experiments"

2017, Patrick Prestele: "Reconstruction of paleo-temperature in Mfabeni peats, SA"

2017, Marcel Labuschagne: "Characterisation of aerosols in the Western Cape, SA"

2017, Gustav Rezelman: "Self-purification potential of Kuilsriver and Stenbras River, Western Cape, SA"

2015, Mari Scott: “Photosynthetic response of Southern Ocean phytoplankton to dust bulk fertilization”

2015, Gillian Trollope: “Establishing a new paleotemperature proxy in the Southern Ocean”

2013-2015, Natasha van Horsten: "Photosynthetic response of Southern Ocean phytoplankton under iron and light limitations"

2013, Ryno Roux: "The applicability of Hydroxy Isoprenoidal -GDGTs as a possible molecular paleoclimate proxy in the Southern Ocean"

List of publications:

  • Fietz S., Baker A., Miller C.S. , Naafs B.D.A., Peterse F., Finch J., Humphries M., Schefuß E, Roychoudhury A.N., Routh J. Terrestrial temperature evolution of southern Africa during the Late Pleistocene and Holocene: evidence from the Mfabeni Peatland (in review, 2021).​
  • Viljoen J.J., Fietz S. Phytoplankton in unique environments in the Atlantic Southern Ocean: fronts, ice and Subantarctic islands (to be submitted, 2021).
  • Kangueehi K., Eckardt F. D., Toesie R., Ravenscroft G. , Fietz S*. Origin, solubility and ocean impact of trace metal aerosols collected over a major iron ore port (in review, 2021).
  • Loock J.C., Cloete R., Mtshali T., Fietz S., Roychoudhury A.N. The biogeochemistry of Cd in the Southern Ocean, Atlantic Sector: lessons learned from a seasonal reoccupation of the ACC (2021, in review).
  • Cloete R, Loock JC, van Horsten N, Fietz S, Mtshali TN,  Planquette H, Roychoudhury AN. Winter biogeochemical cycling of dissolved and particulate cadmium in the Indian sector of the Southern Ocean (GEOTRACES GIpr07 transect). Frontiers in Marine Sciences (2021, in review).
  • Cloete R., J.C. Loock, N.R. van Horsten, J-L. Menzel Barraqueta, S. Fietz, T.N. Mtshali, H. Planquette, M.I. García-Ibáñez, A.N. Roychoudhury. Winter dissolved and particulate zinc in the Indian Sector of the Southern Ocean: Distribution and relation to major nutrients (GEOTRACES GIpr07 transect). (in review, 2021).
  • Singamshetty KM, Routh J , Fietz S, Lone MA, Mangini A. Sources, Distribution and Paleoenvironmental Application of Fatty Acids in Speleothem Deposits from Krem Mawmluh, Northeast India. Frontiers in Earth Sciences (2021). doi: 10.3389/feart.2021.687376
  • Farmer J, Hertzberg J, Cardinal D, Fietz S, Hendry K, Jaccard S, Paytan A, Rafter P, Ren H, Somes C, Sutton J., GEOTRACES-PAGES Biological Productivity Working Group Members. Assessment of C, N and Si isotopes as tracers of past ocean nutrient and carbon cycling. Global Biogeochemical Cycles, e2020GB006775 (2021),
    also see the companion paper: Horner et al. Bioactive trace metals and their isotopes  as paleoproductivity proxies: An assessment using GEOTRACES-era data. Global Biogeochemical Cycles, e2020GB006814 (2021).
  • Weir I, Fawcett S, Smith S, Walker D, Bornmann T, Fietz S*. Winter biogenic silica and diatom distributions in the Indian Sector of the Southern Ocean. Deep Sea Research Part I, 103421 (2020).
  • Fietz S*, Ho SL, Huguet C, Archaeal membrane lipid-based paleothermometry for applications in polar oceans, Oceanography 33, 104-114,​.
  • Viljoen J, Weir I, Fietz S*, Cloete R, Loock J,​ Philibert R, Roychoudhury AN. Links between phytoplankton community composition and trace metal distribution in the surface waters of the Atlantic Southern Ocean. Frontiers in Marine Science, 6:295,
  • Grand MM, Laes-Huon A, Fietz S, Resing JA, Obata H, Luther GW, Tagliabue A, Achterberg EP, Middag R, Tovar-Sanchez A, Bowie A (2019) Developing autonomous observing systems for micronutrient trace metals. Frontiers in Marine Science 6:35,
  • Cloete R, Loock JC, Mtshali TN, Fietz S, Roychoudhury​ AN. (2019)​ Winter and summer distributions of Copper, Zinc and Nickel along the International GEOTRACES section GIPY05: Insights into deep winter mixing.​ Chemical Geology 511, 342-357
  • Viljoen JJ, Philibert R, van Horsten N, Mtshali TN, Roychoudhury A, Thomalla S, Fietz S(2018)​ Response of phytoplankton in growth, community structure and photophysiology to iron and light addition in the Polar Frontal and Antarctic Waters of the Southern Ocean. Deep Sea research I, 141, 118-129​
  • Huguet C, Routh J, Fietz S, Mahjoor AL, et al. (2018) Temperature and Monsoon Tango in a Tropical Stalagmite: Last Glacial-Interglacial Climate Dynamics​. Scientific Reports, 8, 5386,  doi:10.1038/s41598-018-23606-w​​
  • Ansorge et al. (2017) Exploring South Africa’s southern frontier:  A 20-year vision for Polar Research through the South African National Antarctic Programme. South African Journal of Science, 113, Art. #a0205.​
  • Huguet C, Fietz S, Rosell-Melé A, Daura X, Costenaro L (2017). Molecular dynamics simulation study of the effect of glycerol dialkyl glycerol tetraether hydroxylation on membrane thermostability, Biochimica et Biophysica Acta (BBA) - Biomembranes 1859, 966-974 .
  • Fietz S, Ho S-L, Huguet C, Rosell-Melé A, Martínez-García A (2016​). Appraising GDGT-based seawater temperature indices in the Southern Ocean. Organic Geochemistry, 102C, 93-105.
  • Baker AR, Landing WM , Bucciarelli E, Cheize M, Fietz S, Hayes CT, Kadko D, Morton PL , Rogan N, Sarthou G, Shelley RU , Shi Z, Shiller A, van Hulten MMP (2016). Trace Element and Isotope Deposition across the Air – Sea Interface: Progress and Research Needs. Philosophical Transactions of the Royal Society A.374, 20160190.​
  • Knies J, Cabedo-Sanz P, Belt ST, Baranwa S, Fietz S, Rosell-Melé A. (2014) The emergence of modern sea ice cover in the Arctic Ocean. Nature Communications, 5, Article number: 5608.
  • Ho SL, Mollenhauer G, Fietz S, Martínez-Garcia A, Lamy F, Rueda G, Schipper K, Méheust M, Rosell-Melé A, Stein R, and Tiedemann R. (2014​) Appraisal of TEX86 and TEX86L thermometries in subpolar and polar regions. Geochimica et Cosmochimica Acta, 131, 213–226.
  • Menges, J., Huguet, C., Alcañiz, J.M., Fietz, S., Sachse, D., Rosell-Melé, A., 2013. Water availability determines branched glycerol dialkyl glycerol tetraether distributions in soils of the Iberian Peninsula. Biogeosciences Discussion 10, 9043-9068.
  • Fietz, S., Prahl, F.G., Moraleda, N. and Rosell-Melé, A., 2013. Eolian transport of glycerol dialkyl glycerol tetraethers (GDGTs) off northwest Africa. Organic Geochemistry 68, 112-118.
  • Fietz, S., Hambach, B., Huguet, C. and Rosell-Melé, A., 2013. Hydroxylated isoprenoidal GDGTs in the Nordic Seas. Marine Chemistry 152, 1-10.
  • Huguet, C., Fietz, S. and Rosell-Melé, A., 2013. Global distribution patterns of hydroxy glycerol dialkyl glycerol tetraethers. Organic Geochemistry 57, 107-118.
  • Rueda, G., Fietz, S. and Rosell-Melé A., 2013. Coupling of air and sea temperatures in the Fram Strait during the last 2000 Years. The Holocene 23, 692-698.
  • Mackay, A.W., Swann, G.E.A., Fagel, N., Fietz, S., Leng, M.J., Morley, D., Rioual, P. and Tarasov, P., 2013. Hydrological instability during the Last Interglacial in central Asia: a new diatom oxygen isotope record from Lake Baikal. Quaternary Science Review 66, 45-54.
  • Fietz, S., Huguet, C., Bendle, J., Escala, M., Gallacher, C., Herfort, L., Jamieson, R., Martínez-Garcia, A., McClymont, E., Peck, V., Prahl, F., Rossi, S., Rueda, G., Sanson-Barrera, A. and Rosell-Melé, A., 2012. Co-variation of crenarchaeol and branched GDGTs in globally-distributed marine and freshwater sedimentary archives. Global and Planetary Change 92, 275-285.
  • Huguet, C., Fietz, S., Moraleda, N., Stockhecke, M., Anselmetti, F.S., Sturm, M., Heumann, G. and Litt, T., 2012. A seasonal cycle of terrestrial inputs in Lake Van, Turkey. Environmental Science and Pollution Research 19, 3628-3635.
  • Rossi, S., Isla, E., Fietz, S., Martínez-Garcia, A., Sañé, E. and Teixidó, N., 2012. Temporal variation of seston biomarkers within the Humboldt Current System off northern Chile (21ºS): first simultaneous records on fatty acids, n-alkanes and glycerol-dialkyl-glycerol-tetraethers. Advances in Oceanography and Limnology 3, 17-40.
  • Fietz, S., Martínez-Garcia, A., Huguet, C., Rueda, G. and Rosell-Melé, A., 2011. Constraints in the application of the BIT index as a terrestrial input proxy. Journal of Geophysical Research – Oceans 116, C10032.
  • Fietz, S., Martínez-Garcia, A., Rueda, G., Peck, V., Huguet, C., Escala, M. and Rosell-Melé, A., 2011. Crenarchaea and phytoplankton coupling in sedimentary archives: Common trigger or metabolic dependence?  Limnology and Oceanography 56, 1907-1916.
  • Huguet, C., Fietz, S., Stockhecke, M., Sturm, M., Anselmetti, F.S. and Rosell-Melé, A., 2011. Biomarker seasonality study in Lake Van, Turkey. Organic Geochemistry 42, 1289-1298.
  • Underwood, G.J.C., Fietz, S., Papadimitriou, S., Thomas, D.N. and Dieckmann, G.S., 2010. Distribution and composition of dissolved extracellular polymeric substances (EPS) in Antarctic sea ice. Marine Ecology Progress Series 404, 1–19.
  • Escala, M., Fietz, S., Rueda, G. and Rosell-Melé, A., 2009. Analytical Considerations for the Use of the Paleothermometer Tetraether Index86 and the Branched vs Isoprenoid Tetraether Index Regarding the Choice of Cleanup and Instrumental Conditions. Analytical Chemistry 81, 2701-2707.
  • Escala, M., Rosell-Melé, A., Fietz, S. and Koeberl, C., 2008. Archaeabacterial Lipids in Drill Core Samples from the Bosumtwi Impact Structure, Ghana. Meteoritics and Planetary Science 43, 1777-1782.
  • Fietz, S., Nicklisch, A. and Oberhänsli, H., 2007. Phytoplankton response to climate changes in Lake Baikal during the Holocene and Kazantsevo Interglacials assessed from sedimentary pigments. Journal of Paleolimnology 37, 177-203.
  • Fietz, S., Kobanova, G., Izmest eva, L.R. and Nicklisch, A., 2005.Regional, vertical and seasonal phytoplankton and photosynthetic pigment distribution in Lake Baikal. Journal of Plankton Research 27, 793-810.
  • Fietz, S., Bleiß, W., Hepperle, D., Koppitz, H., Krienitz, L. and Nicklisch, A., 2005. First record of Nannochloropsis limnetica (Eustigmatophyceae) in the autotrophic picoplankton of Lake Baikal. Journal of Phycology 41, 780-790.
  • Fietz, S., Sturm, M. and Nicklisch, A., 2005. Flux of photosynthetic pigments to the surface sediments of Lake Baikal. Global and Planetary Change 46, 29-44.
  • Straskrábová, V., Izmest'yeva, L.R., Maksimova, E.A., Fietz, S., Nedoma, J., Borovec, J., Kobanova, G.I., Shchetinina, E.V. and Pislegina, E.V., 2005. Primary production and microbial activity in the euphotic zone of Lake Baikal (Southern Basin) during late winter. Global and Planetary Change 46, 57-73.
  • Heim, B., Oberhänsli, H., Fietz, S. and Kaufmann, H.,  2005. Variation in Lake Baikal´s phytoplankton distribution and fluvial input assessed by SeaWiFs satellite data. Global and Planetary Change 46, 09-27.
  • Fietz, S. and Nicklisch, A., 2004. An HPLC analysis of the summer​ phytoplankton assemblage in Lake Baikal. Freshwater Biology 49, 332-345.
  • Fietz, S. and Nicklisch, A., 2002. Acclimation of the diatom Stephanodiscus neoastraea and the cyanobacterium Planktothrix agardhii to simulated natural light fluctuations. Photosynthesis Research 72, 95-106.
  • Nicklisch, A. and Fietz, S., 2001. The influence of light fluctuations on growth and photosynthesis of Stephanodiscus neoastraea (diatom) and Planktothrix agardhii (cyanobacterium). Archive of Hydrobiology 151, 141-156. 10.1127/archiv-hydrobiol/​151/2001/141