Cetacean chronicles: Exploring Ecology and Proxy Potential from whale teeth

Marine mammals such as whales are an integral part of the oceanic ecosystems, however, they are also heavily affected by anthropogenic impact. In order to assess the long-term human impacts on modern whales, it is necessary to establish reliable baselines of their past and present populations.

In this study we analyzed both modern and subfossil teeth from sperm whales (Physeter macrocephalus) and harbor porpoises (Phocoena phocoena). Growth layers of the teeth were investigated by the use of SEM-BSE, to gain insight into the growth dynamics and age of our specimens. Since the tooth enamel is an important indicator of diet, migration and habitat, we used Sr/Ca ratios to reconstruct the ecological niches of our taxa.

Raman spectroscopy was implemented to investigate teeth surface structure and
crystallographic structure, and EDX allowed us to study the chemical composition of the teeth. In conclusion, this study provides valuable insight into the ecology of modern and subfossil whales and an assessment of chemical and structural proxies that can be utilized.