Københavns Universitet
Uafhængig af ledelsen


PhD defence: Karla B. Parga Martínez

Ph.d.-forsvar — Karla B. Parga Martínez 9 APRIL


Date & Time:

Aud C, Department of Geosciences and Natural Resource Management, Øster Voldgade 10, 1350 Kbh K

Hosted by:
Geology Section -


Karla B. Parga Martínez defends her thesis,

An anthropogenic archive of plastic pollution in Greenland.

Associate Professor Nicole Posth, IGN
Professor Thorbjørn J. Andersen, IGN

Assessment Committee:
Senior Scientist Victoria Peck, British Antarctic Survey, UK
Associate Professor Alvise Vianello, Aalborg University
Associate Professor Christian J. Bjerrum (chair), IGN

Abstract (shortened):
The duality of plastics as a marvelous material and a pollutant of growing concern has led to conflicting use and management. Plastics’ durability and stability properties were rapidly utilized across industries resulting in versatile applications and widespread use. However, poor waste management practices and unforeseen harmful effects have driven to the current plastic crisis of toxic chemicals, massive plastic waste and imperceptible sub-micron particles. Regardless of the source, plastic transportation pathways lead to the ocean and the seafloor is viewed as a sink for microplastics (MP). Microplastics have spread throughout the marine environment and even to the northernmost latitudes: the Arctic. This generally pristine environment faces plastic pollution differently; extreme low temperatures, prolonged diurnal cycles, lack of waste management infrastructure, and remoteness challenge conventional approaches such as waste sorting and recycling. Unsurprisingly, reports on MP pollution show high quantities throughout the Arctic and sub-Arctic region with a clear data gap around Greenland. In fact, global plastic budget models do not have data for Greenland as only a few studies have been conducted and have been restricted mostly to East Greenland. Greenlandic economy relies heavily on fishing and tourism (maritime transport), which are also the main sea-based sources of plastic pollution. A signal of anthropogenic activities like these may imprint in the sedimentary record as a footprint of the Anthropocene. Once on the seafloor, MP particles are buried in the sediment and are eventually incorporated into the geological record. This PhD thesis aims to address the plastic pollution data gap in Greenland, particularly in West Greenland by developing an extraction method for fine-grained Arctic sediment that allowed the reconstruction of an 85-year MP record in Disko Bay, which served as a baseline to explore nanoplastics (NP) fate at the sediment sink. This thesis provides the first numbers of plastic pollution in the Avannaata Commune and only the third MP report in West Greenland.

A digital version of the PhD thesis can be obtained from the PhD secretary at phd@ign.ku.dk