Clues about historical climate and ecosystems in Icelandic sediment

Can we see what the biosphere was like off the coast of Iceland thousands of years ago? Yes!

Using specialised equipment to excavate sediment from the ocean floor at the Reykjanes ridge, it is possible to analyse the core almost year by year and discover the ecological and meteorological factors that helped to shape it. This was the mission at hand when Árni Friðriksson, the Marine Research Institute's vessel, set sail on a two-week expedition from the south of Iceland to collect samples from the sediment on the sea bed. New technology will be used to analyse ancient DNA in the samples, so-called eDNA, which will help researchers shed light on the relationship between the climate and marine ecosystems thousands of years in the past. 

An interdisciplinary team of scientists at ROCS (HM Queen Margrethe II's and Vigdís Finnbogadóttir's Interdisciplinary Research Centre on Ocean, Climate and Society) was on board Árni Friðriksson. Besides the core samples from the ocean floor, they also collected samples from the sea itself. ROCS is affiliated with the University of Iceland and the University of Copenhagen.  

Scientists at work on board Árni Friðriksson

"Humans have been able to identify ancient organisms for a very long time, but only fossilised remains," says Arndís Bergsdóttir, a postdoctoral researcher at ROCS who is representing the project in Iceland. She was part of the research team that set sail on board Árni Friðriksson. "But using ancient or eDNA technology allows us to identify DNA that has collected on the ocean floor and tells us what the biosphere was like along the coast of Iceland at that time."

Arndís explains that the team are focusing on how the composition and behaviour of phytoplankton could be related to carbon dioxide in the atmosphere. "Ancient DNA provides us with information about the animals that were living in the sea, which helps us understand what the ecosystem was like. Plankton behaviour can also give us clues about climate, which is something we will be addressing in the final conclusions of the study. We will then link that to our findings from samples collected from Icelandic lakes. And alongside this, we are also researching human society and culture to find out how these different factors worked together," says Arndís. 

"We are analysing the core samples we collected on the expedition, looking for remains of ancient DNA, which will enable us to describe how the marine biosphere changed in relation to the climate, thousands of years ago," explains Katherine Richardson, professor of marine oceanography at the University of Copenhagen who led the expedition. She also leads the Sustainability Science Centre at the University of Copenhagen.

See this video to learn more about ROCS

Close links with the UN Sustainable Development Goals

This summer's expedition was part of an extensive Danish-Icelandic research project using this new technology to analyse data, which for the first time enables scientists to map entire ecosystems and look at how they have changed in the context of climate change.  

The project is therefore directly linked to the SDGs. Research into historical climate change can help to shape appropriate responses to current climate change. Katherine Richardson says that the findings from this study will significantly advance our understanding of how ecosystems respond to climate change. 

Katherine has led many projects researching climate issues and sustainability and has held positions of responsibility in the field. For example, she was one of 15 independent scientists appointed by the Secretary-General of the United Nations to draft a report on sustainable development for the UN. 

What impact has climate change had on communities in Iceland?

"The project also looks at how marine and land ecosystems have affected Icelandic society and how societal changes and human intervention have influenced changes to the biosphere. Iceland is an ideal place to do this research because of its remoteness, the importance of the biosphere to the nation's economy and also good access to sources about Icelandic society and culture," explains Arndís. 

The new Strategy of the University of Iceland, UI26, places special emphasis on removing barriers between units and encouraging interdisciplinary collaboration in research. The ROCS project certainly aligns with the strategy, since the research team on board Árni Friðriksson this summer included scholars from the natural sciences, social sciences and humanities. "It's quite a novelty for academics from such different fields to work so closely on a project from the outset, creating comprehensive knowledge through different research methods," says Arndís. "This expedition turned out to be a unique opportunity, not just because of the data we collected but also the way academics from different fields united to create new knowledge about the relationship between the ocean, climate and society. A few semesters ago, I would never have thought that there would be any demand for me, a social scientist, on board a marine research vessel," says Arndís with a smile.

"We are analysing the core samples we collected on the expedition, looking for remains of ancient DNA, which will enable us to describe how the marine biosphere changed in relation to the climate, thousands of years ago," explains Katherine Richardson, professor of marine oceanography at the University of Copenhagen who led the expedition. She also leads the Sustainability Science Centre at the University of Copenhagen.