Jan Grimsrud Davidsen

Jan Grimsrud Davidsen is a research professor at the Norwegian University of Science and Technology (NTNU) University Museum in Trondheim, Norway. In this interview, we discuss the use of acoustic telemetry and ecological sampling to study the impacts of climate change on Arctic charr in the fjords of Southwestern Greenland.  

Tell us about your research questions:

Our research looks at how climate change is affecting the migration and feeding habits of Arctic charr in Southwestern Greenland. Arctic charr exhibit partial migration, where some individuals migrate to the sea for feeding while others remain in freshwater. Our key research questions include:

• How do environmental changes, such as shifts in temperature and freshwater inflow, influence the migratory behaviour of Arctic charr?
  We’re trying to determine whether climate change is altering the timing, duration, and extent of marine migrations, and how these changes impact the balance between migratory and resident groups within the population. 

• What are the differences in migratory tactics and marine habitat use between Arctic charr populations in two contrasting fjord systems?
  By comparing a fjord system that receives glacial runoff with one that does not, we can better understand how environmental variability influences migration patterns and habitat use. 

• How do differences in diet and feeding habits vary between migratory groups, and how might these change with shifting environmental conditions?
  We’re studying how the diets of different groups of Arctic charr (i.e. those that migrate to the sea and those that don’t) vary, and how these diets might change as the environment shifts. We hope to learn how changes in food availability and environmental conditions could have an impact on the fish and the role they play in the food web. 

By addressing these questions, our research will provide critical insights into the resilience of Arctic charr populations and their ability to adapt to ongoing climate change.

Why is this research important?   

This research is essential because the current lack of knowledge about the migratory tendencies of Arctic charr makes it difficult for resource managers to protect the full range of migratory behaviours within populations. Maintaining a diverse portfolio of migration strategies, as highlighted by Schindler et al. (2010), is crucial for ensuring population resilience in the face of climate change. Without a clear understanding of how environmental changes affect migratory behaviour, there’s a risk of losing key behavioural types, which could reduce the species’ adaptability and threaten population stability.   

What makes Greenland an important study area?

Greenland is an ideal location to study these changes because it’s one of the Arctic regions most vulnerable to climate change (IPCC, 2014), with rapidly shifting environmental conditions that are likely to affect Arctic charr populations. Additionally, Arctic charr are a vital cultural and food resource for local communities, making it crucial to understand how climate change may impact this species. Studying Arctic charr in relatively undisturbed sites, such as those in Southwestern Greenland, provides a unique opportunity to assess natural variability and responses to environmental changes with limited influence from other anthropogenic impacts. This knowledge is vital for informing effective conservation and management strategies in a rapidly changing climate.   

Can you share any initial findings? 

For this project, we tagged 80 Arctic charr with acoustic tags to track their movement patterns. We’re still in the process of analyzing the data, but initial results show clear differences in the migratory behaviours and habitat use between the two fjord systems.   

Copyright Per Gatzschmann

How does OTN support your project?

OTN has been instrumental in supporting our research by loaning us 44 acoustic receivers, which are critical to our data collection. This equipment allows us to gather tracking data from the Arctic charr across the two fjord systems. The support from OTN has been invaluable in helping us carry out our research effectively and ensuring the success of the project.