Internship Controlled growth experiments yield insight into bivalve shell mineralization and chemistry
The shells of bivalve molluscs are of great interest for paleoclimate, paleoenvironmental and paleobiology research, because their chemistry potentially harbours information about the conditions under which the animal grew (e.g. Surge et al., 2001; Gillikin et al., 2005; Butler et al., 2010). Since bivalves grow over a period of several years and have a great fossilization potential, this property allows their shells to be used to reconstruct seasonal changes in climate and environment, millions of years in the past (Steuber et al., 2005; Ivany, 2012). However, the exact link between shell chemistry and environmental change is still not fully understood (Weiner and Dove, 2003).
Description
The goal of this project is to study the link between environmental change and bivalve shell composition by growing bivalves under known environmental conditions. The species Cerastoderma edule (the common cockle), Ostrea edulis (the European flat oyster) and Arctica islandica (the long-lived ocean quahog) will be used to cover a wide variety of bivalve species from different parts of the bivalve family tree with different shell structures.
The growth experiments take place in climate-controlled tanks at the NIOZ Estuarine and Delta Systems lab, where water composition, food and temperature can be precisely controlled. During the growth period, samples are taken of the water for trace element analyses. After these growth experiments, the shells of the bivalves are subject to a detailed investigation of their shell microstructure and chemistry. This way, changes in growth rate, microstructure and shell chemistry can be linked to changes in the environment, leading to better proxies for studying past climate and environment from fossil bivalve shells.
The project focuses in particular on the role of changing environmental conditions and growth rate on the uptake of trace elements into the bivalve shell from the environment.
Requirements and application
This MSc student project is jointly supervised by Dr. Niels de Winter (UU) and Dr. Rob Witbaard (NIOZ). We are looking for highly motivated MSc students who have a keen interest in research on the cutting edge between mineralogy, biology and (paleo)climatology. They should be familiar with microscopic techniques and have a basic background in analytical chemistry. Students will be responsible for managing growth experiments under supervision of dr. Rob Witbaard at the NIOZ in the spring season (February-April/May). Analytical measurements will be carried out and interpreted under the supervision of dr. Niels de Winter partly at the NIOZ and in part at Vrije Universiteit Amsterdam. If you feel ready to take part in this exciting research project, feel free to contact us!
For more information, please contact Niels J. de Winter, Vrije Universiteit Amsterdam (n.j.de.winter@vu.nl ) and/or Rob Witbaard, Estuarine and Delta Systems (EDS), Royal Netherlands Institute for Sea Research (NIOZ) (rob.witbaard@nioz.nl).
References
Butler PG, Richardson CA, Scourse JD, Wanamaker AD, Shammon TM, Bennell JD. Marine climate in the Irish Sea: analysis of a 489-year marine master chronology derived from growth increments in the shell of the clam Arctica islandica. Quaternary Science Reviews. 2010;29(13):1614–1632.
Gillikin DP, De Ridder F, Ulens H, Elskens M, Keppens E, Baeyens W, et al. Assessing the reproducibility and reliability of estuarine bivalve shells (Saxidomus giganteus) for sea surface temperature reconstruction: implications for paleoclimate studies. Palaeogeography, Palaeoclimatology, Palaeoecology. 2005a;228(1):70–85.
Ivany LC. Reconstructing paleoseasonality from accretionary skeletal carbonates—challenges and opportunities. The Paleontological Society Papers. 2012;18:133–166.
Steuber T, Rauch M, Masse J-P, Graaf J, Malkoč M. Low-latitude seasonality of Cretaceous temperatures in warm and cold episodes. Nature. 2005;437(7063):1341–1344.
Surge D, Lohmann KC, Dettman DL. Controls on isotopic chemistry of the American oyster, Crassostrea virginica: implications for growth patterns. Palaeogeography, Palaeoclimatology, Palaeoecology. 2001 Aug 15;172(3):283–96.
Weiner S, Dove PM. An overview of biomineralization processes and the problem of the vital effect. Reviews in mineralogy and geochemistry. 2003;54(1):1–29