Environmental Physiology

The working group 'Environmental Physiology' (Research Division Marine Ecology, Research Unit Benthic Ecology) is interested in marine invertebrate physiology, particularly with respect to phenotypic plasticity and adaptation capacity to a changing climate (ocean acidification, ocean warming, hypoxia). We are particularly curious about how marine calcifiers (molluscs, echinoderms, corals) and plankton are able to maintain acid-base equilibria and how they are able to form biominerals that can withstand great chemical stresses. We are conducting both, field and laboratory experiments and are particularly interested in the natural variability in carbonate system speciation along coastal ecosystems. We collaborate with scientists from the disciplines of geology, ecology, biogeochemistry, marine chemistry, medicine and zoology.



Our labs and offices are located in Hohenbergstrasse 2, 24105 Kiel.

Contact details: Frank Melzner (+49 431 600 4274, fmelzner(at)geomar.de), Ulrike Panknin (lab management, +49 431 600 4272, upanknin@geomar.de).

Team members

  • PD Dr. Frank Melzner (PI benthic systems & meroplankton); marine invertebrate zoology & environmental physiology, acid base regulation, biomineralization. Publications (google scholar).
  • Dr. Marlene Wall (PI coral ecophysiology, benthocosm research). Publications (google scholar).
  • Ulrike Panknin (MTA); algae cultures, molecular biology, lab manager.
  • M.Sc. Imke Podbielski (PhD student, Studienstiftung); osmoregulatory limits to life in the brackish Baltic Sea.
  • B.Sc. Andrea Lee Schmidt (M.Sc. student); heat tolerance in tropical reef corals (Pocillopora) in Thailand & reproductive ability (supervision Wall / Melzner).
  • B.Sc. Anna Fiesinger (M.Sc. student); population structure of corals (Pocillopora) in Thailand (supervision Wall / Melzner).
  • B.Sc. Sarah Joy Hahn (M.Sc. student); impacts of winter warming on energy budgets in sea stars (supervision Melzner).
  • Merlin Weichler (B.Sc. student); heat tolerance mechanisms of coastal gastropods (supervision Melzner).
  • Jannis Hümmling (B.Sc. student); microbiome changes in sea stars during summer heat waves (supervision Melzner / Hentschel-Humeida).

Guest  researcher:

  • Dr. Rainer Kiko influence of zooplankton on biogeochemistry of oxygen minimum zones, zooplankton stress physiology & ecology.

Former members:

  • B.Sc. Alessia Carini (M.Sc. student); now: PhD student University of Hong-Kong (Thiyagarajan lab).
  • M.Sc. Lara Schmittmann (M.Sc. student); now: PhD student GEOMAR (Hentschel-Humeida lab).
  • M.Sc. Jenny Nascimento Schulze (M.Sc. student); now: PhD student University of Exeter (Ellis lab).
  • Dr. Claas Hiebenthal (Postdoc); now: head, Kiel Marine Organism Culture Centre (KIMOCC), GEOMAR.
  • Dr. Anna Schukat (Postdoc); now: Postdoc, University of Bremen (Hagen lab).
  • Dr. Trystan Sanders (PhD student); now: taxonomist, New Zealand.
  • Dr. Kirti Ramesh (PhD student, Postdoc); now: Postdoc, University of Gothenburg (Dupont lab).
  • M.Sc. Etienne Lein (M.Sc.); now: PhD student MPI Ornithology / collective behaviour, Konstanz.
  • Dr. Marian Hu (PhD, Postdoc); now: Emmy Noether group leader, CAU Kiel.
  • Dr. Rainer Kiko (Postdoc); now: Make Our Planet Great Again group leader, Villefranche / Paris University.
  • Dr. Jörn Thomsen (PhD, Postdoc); now: scientist / industry.
  • Dr. Meike Stumpp (PhD, Postdoc); now: lecturer / Emmy Noether group leader, CAU Kiel (Leippe lab).
  • Dr. Anne Hüning (Postdoc); now: scientist / industry.
  • Dr. Agnes Heinemann (PhD); now: scientist / science education MINT.
  • Dr. Katja Trübenbach (Diplom); now: teacher.
  • Dr. Sandra Fehsenfeld (Diplom); now: Postdoc, University of British Columbia, Vancouver, Canada (Wood - lab).
  • Dr. Julia Saphörster (Diplom); now: scientist / industry.
  • Dr. Corinna Breusing (M.Sc.); now: Postdoc, University of Rhode Island, USA.

Selected publications

  1. Melzner, F., Panknin, U., Buchholz, B., Wall, M. (2020). Ocean winter warming induced starvation of predator and prey.  Proceedings of the Royal Society B  287:20200970.

  2. Melzner, F., Mark, F.C., Seibel, B.A., Tomanek, L. (2020). Ocean acidification and coastal marine Invertebrates: tracking CO2 effects from seawater to the cell. Annual Review of Marine Science 12:499-523.

  3. Wall, M., Fietzke, J., Crook, E.D., Paytan, A. (2019). Using B isotopes and B/Ca in corals from low saturation springs to constrain calcification mechanisms. Nature Communications 10:3580.

  4. Ramesh, K., Hu, M.Y.A., Thomsen, J., Bleich, M., Melzner, F. (2017). Mussel larvae modify calcifying fluid carbonate chemistry to promote calcification. Nature Communications 8:1709.

  5. Thomsen, J., Stapp, L.S., Haynert, K., Schade, H.Danelli, M., Lannig, G., Wegner, K.M., Melzner, F. (2017). Naturally acidified habitat selects for ocean acidification–tolerant mussels. Science Advances 3: e1602411

  6. Thomsen, J., Casties, I., Pansch, C., Körtzinger, A., Melzner, F. (2013). Food availability outweighs ocean acidification effects in juvenile Mytilus edulis: laboratory and field experiments. Global Change Biology 19:1017-1027.

  7. Melzner, F., Thomsen, J., Koeve, W., Oschlies, A., Gutowska, M.A., Bange, H.W., Hansen, H.P., Körtzinger, A. (2013). Future ocean acidification will be amplified by hypoxia in coastal habitats. Marine Biology 160:1875-1888.

  8. Stumpp, M., Hu, M.Y., Melzner, F., Gutowska, M.A., Dorey, N., Himmerkus, N., Holtmann, W., Dupont, S.T., Thorndyke, M.C., Bleich, M. (2012). Acidified seawater impacts sea urchin larvae pH regulatory systems relevant for calcification. Proceedings of the National Academy of Sciences of the USA 109:18192-18197.