The Heide-Jørgensen group is based at the Greenland Institute of Natural Resources and consists of senior scientist Eva Garde, professor Susanne Ditlevsen, PhD Student Lars Reiter Nielsen and professor Mads Peter Heide-Jørgensen.

 The Heide-Jørgensen group is looking at information on changes in narwhals’ life history and environment that is hidden in the dentinal layers in the tusk. Specifically, the group is looking at changes in elemental composition and isotopes in dentinal layers over time and in different areas, and changes in hormone profiles at life history events like onset of sexual maturity, pregnancy and nursing. For the understanding of life history events, it is also important that the age of the whales can be properly assessed and the Heide-Jørgensen group is investigating methods for validation of age estimation techniques, including carbon isotope signatures from before and after the last hydrogen bomb, and the cyclical nature of elemental deposition in the tusks. The studies involve complex statistical analysis of time series and development of statistical methods for analyzing elemental patterns in the tooth material. The Heide-Jørgensen group also contribute to the project with samples of tusks and embedded teeth from narwhals captured in the legal Inuit hunt in East and West Greenland.

 Outside this project the Heide-Jørgensen group also work with assessment of narwhal stocks in relation to hunting and climate changes, estimation of biological parameters, and the physiological effects of disturbances on narwhals.