Research expedition studies Oxygen Minimum Zones off the coast of Chile
Laura Bristow, researcher in marine chemistry, and her research team is currently off the coast of Chile on the Schmidt Ocean Institute international research expedition Microbes in Oxygen Minimum Zones. Using a newly developed underwater laboratory, they are studying microbes in oxygen depleted areas to find out how they affect the future climate.
Hej Laura! What are you doing right now?
"We are currently on an expedition aboard the research vessel RV Falkor (too) off Iquique on the northern Chilean coast. This oceanic region is characterized by extremely low oxygen concentrations. Our main interest is to understand key processes of microbial turnover of nitrogen compounds under different oxygen regimes, and how microbial processes contribute to the production of the climate-relevant greenhouse gas nitrous oxide in this environment. The core of these Oxygen Minimum Zones is anoxic, and therefore inhospitable for most animals. However, these areas harbour thriving microbial communities that are adapted to anoxic conditions and play an important role in various biogeochemical processes, in particular the cycling and turnover of nitrogen compounds."
Why is this important?
"Oxygen Minimum Zones (OMZs) play a crucial role in Nitrogen cycling, where microbial processes either remove or recycle nitrogen compounds depending on oxygen availability. Moreover, N cycling in OMZs is considered a significant source of nitrous oxide, a potent greenhouse gas contributing to global warming. Due to climate change, the oxygen-depleted regions are expected to expand globally. Hence, comprehending the environmental controls on microbial nitrogen cycling in OMZ, particularly in relation to oxygen availability, is crucial for assessing marine productivity and global climate regulation."
What are the challenges with this type of research?
"It has always been very difficult to study processes that occur deep in the ocean. If you try to recreate the processes in a laboratory environment, alterations in pressure, temperature, and light within laboratory settings as opposed to the natural environment may influence microbial activities, potentially leading to an incomplete or biased understanding.
However, our recent development of an underwater laboratory in collaboration with Woods Hole Oceanographic Institute and the University of Southern Denmark addresses these challenges by enabling us to study microbial processes in situ, and thus under conditions that are representative of the chemical and physical conditions of the OMZ."
What are you hoping to find?
"With this novel approach, we hope that our data will better inform ocean climate models and improve predictions of the impact of the expected expansion of oceanic OMZ on nitrogen cycling and the emissions of nitrous oxide from this biogeochemically important oceanic region. Collectively, this dataset will hopefully allow us to better constrain the activity of nitrogen-cycling microorganisms in the OMZ off Chile and predict their responses to the expected decrease in aquatic oxygen levels due to climate change."
Writer: Annika Wall
The research expedition is called "Microbes in Oxygen Minimum Zones" and organised by the Schmidt Ocean Institute. It runs from 12 April - 15 May, 2024.
Read more about the expedition here.
Participating researchers from the University of Gothenburg, Department of Marine Sciences, are: Laura Bristow, researcher, Sina Schorn, post doc, and Alisa Wüst, PhD Student.
The new underwater laboratory used by the researchers is developed in collaboration with Woods Hole Oceanographic Institute and the University of Southern Denmark, and is called CockTail - Chamber Oxygen Collector Kit Trace Analyser Insitu Logger.
CockTail collects and processes seawater samples at specified depths, thus allowing the researchers to study biogeochemical processes in situ.
