PhD: Conservation paleobiology of toothed whales of the North Atlantic

Job description

We are looking for a candidate to fill a prospective PhD position in the project “Conservation paleobiology of toothed whales of the North Atlantic” carried out in collaboration between the Department of Earth Sciences (Faculty of Geosciences) and the Department Biomolecular Health Sciences (Faculty of Veterinary Medicine) at Utrecht University. This project will apply geochemical methods to unravel changes in the habitat and ecology of toothed whales in the North Sea during the last millennia, focusing on the anthropogenic impact.

Whales are critical organisms in the Earth’s ocean ecosystems. Increased shipping, the construction of off-shore wind farms and rising sea temperatures have decimated their populations. Because whales have long lifespans and migrate over large areas, we do not have an ecological baseline to evaluate their population dynamics and shrinking of habitats. Such information is, however, available in the historical (the last few centuries old) and fossil whale remains in the North Sea. Geoscientific expertise can aid conservation by unlocking environmental and ecological records from these remains. In this project we will focus on whale teeth, as teeth are often the only part of the organism which becomes preserved. Owing to its chemical stability, tooth enamel preserves environmental information of the organism’s diet, migrations and temperature.

Objectives of the project:

Identification of the mechanism of alteration of O and Sr isotopic and trace element composition of whale enamel in marine diagenetic conditions;
quantifying changes in the crystallographic texture caused by alteration;
formulating a screening protocol allowing to identify pristine proxy values or correct for altered proxy values in enamel;
reconstructing migrations and trophic and thermal niches of Pleistocene North Atlantic whales using the methodology developed in this project.

Approach:
Your tasks will be to sample whale teeth from fossil collections in museums and from recently stranded and deceased whales at the Faculty of Veterinary Medicine. The animals keep their teeth throughout their lives. We will target sperm whales and harbor porpoises, as both species are of acute interest in terms of population decline, but they represent different ecologies. You will carry out isotopic, elemental and mineralogical analyses, as well as experimental diagenesis, on modern teeth. In parallel to laboratory work, you will compile information on the distribution and ecology of sperm whales and harbor porpoises in the North Sea to evaluate how well the geochemical proxies reflect this knowledge. Based on the results of experimental diagenesis, you will evaluate whether these proxies can be applied to fossil whale teeth and you will carry out a proxy reconstruction in fossil specimens to compare the ecological information with modern whales. If material from tagged animals can be obtained, it will allow cross-testing our reconstructions.

The position is funded by the Geosciences Strategic Themes programme awarded to Emilia Jarochowska (Geosciences) and Lonneke IJsseldijk (Veterinary Medicine). It includes a work contract for four years, as well as a budget for research, travel and publication expenses to support the PhD project. The project will involve collaboration with Helen King (Raman spectroscopy, biomineralisation), Lubos Polerecky (NanoSIMS) and Philip Riekenberg (Royal NIOZ, whale ecology).

You will be based at Utrecht University, but the project foresees travel for training, research collaboration, and meeting with project partners. A personalised training programme will be set up, reflecting your training needs and career objectives. About 20% of your time will be dedicated to this training component, which includes training on the job in assisting in the BSc and MSc teaching programmes of the Earth Sciences department at Utrecht University. We also expect the willingness to dedicate part of the work time to public engagement related to the project, such as public talks or writing for non-specialist audience. Training and support in public engagement is available at Utrecht University.