Phd Position in Arctic Mercury Cycling and Climate Change-related Pathways: Using Stable Isotopes to Explore Sources, Ecosystem Dynamics and Risks to Biodiversity

Applicants are invited for a PhD Fellowship/Scholarship at Graduate School of Technical Sciences, Aarhus University, Denmark, within the Ecoscience programme. The position is available from 01 January 2025 or later. You can submit your application via the link under 'how to apply'.

Title:

Arctic Mercury Cycling and Climate Change-related Pathways: Using Stable Isotopes to Explore Sources, Ecosystem Dynamics and Risks to Biodiversity (Phd Position)

Research area and project description:

Background:

Mercury (Hg) is among the most toxic heavy metals and its occurrence in the Arctic environment has increased markedly since pre-industrial times. The Hg originates from both natural and anthropogenic sources and is transported to the Arctic via the atmosphere, rivers, and ocean currents. Since the dawn of industrialization, an ever-increasing fraction of Hg has been released from human activities, mainly burning of fossil fuels, production of concrete, and small-scale gold mining. This has resulted in significant increases of Hg in Arctic biota with concentrations being up to 20-30 times higher compared to ancient pre-historic concentrations. Once Hg enters the Arctic food web, it bioaccumulates in biological tissue and biomagnifies along the food chain into top predators such as toothed whales, polar bears, and humans. This causes threats due to adverse neuro-endocrine disruption of both wildlife and the northern communities consuming country food including whales, polar bears and other wildlife.

Historically, studies have focused on total Hg contents when studying spatial-temporal trends and there is currently important knowledge gaps associated with the Hg sources and pathways affecting deposition, mobilization, uptake, and trophic transfer in the Arctic. In recent years, technical advances in mass spectrometry have enabled precise analysis of Hg stable isotopes (Hg-SI) and an opportunity to further study Hg sources and biogeochemical pathways creating significant scientific momentum. Aarhus University has played a leading role in Arctic Hg studies during the past 40 years and has recently build a laboratory facility to study Hg-SI (link).

The project:

The PhD position is connected to the research project ‘GreenPath: Greenland stable mercury isotopes: from Holocene sources to modern time-series and pathways’ recently funded by the Independent Research Fund Denmark and will run for 3 years (link). The project is cross-disciplinary and will fucus on investigation of Hg-SI in environmental sample matrices in Greenland and other Arctic areas to provide new knowledge on the mercury cycle. Key research questions that will be addressed include:

How has climate change and atmospheric Hg deposition in the Arctic changed through Holocene? Can recent anthropogic Hg be separated from legacy Hg using Hg-SI?

Is the increase in Hg in top predators since the industrialization a risk to biodiversity and is it linked to changes in Hg-SI? Can these be used to identify sources and pathways?

How are internal metabolic processes affecting Hg-SI fractionation in Arctic key species? How can different tissues be applied to study sources and pathways for Hg uptake?

Please read the full job description and apply by clicking the 'Apply' button

Application deadline

30 September 2024 at 23:59 CEST

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