Stained microbes in seawater, magnified with a fluorescence microscope.
Stained microbes in seawater, magnified with a fluorescence microscope.
Photo: Carina Bunse

Marine Microbial Ecology Group – MMEco

Research group

Short description

We study the microbes of the sea. How do they adapt to changes in the ecosystem and at which rates? How do they interact with other microbial organisms? How do communities change in space and time? Which roles and functions do these microbes have in the ocean? To learn about the organisms, we use lab and field experiments and join research expeditions where we extract DNA from the environment and measure rates of different chemical reactions that are performed by microbes.

We are a new working group and welcome enthusiastic students, PhD students and postdocs to join us! If you like to learn more about our research, please contact Carina directly.

Logo for Marine Molecular Ecology Group


Carina Bunse, Associate Senior Lecturer at the Department of Marine Sciences

Nicolai Laufer, PhD student at the Department of Marine Sciences

MMEco Highlights

New term, new projects, new team members

 This year started with some exciting personnel and student additions to the group. Ms student Hedda Matteoni is joining the MethanTron team (see below) to analyse the effects of methane on bacterial communities. Ms student Mateusz Benkowski is trying to solve the riddle of the fluorescent layer in the nearby Byfjorden, and whether it is of microbiological origin. PhD student Nicolai Laufer started a sampling campaign in collaboration with Sjöfartsmuseet Akvariet in Gothenburg to study the assembly of microbial communities in different saltwater ecosystems. Stay tuned for more information about these projects coming soon!

Photo: Nicolai Laufer

Hands on for plankton research – MethanTron

Members of the new project on plankton and methane, MethanTron, met at the Planktotrons (indoor mesocosm facility) at the Institute for Chemistry and Biology of the Marine Environment in Wilhemshaven, Germany, end of September and took seawater samples. The excitement spread when we saw many different species in the diverse phytoplankton communities under the microscope. We found very long chains of diatoms, spinning and swimming flagellates and ciliates that would swirl in and out of the frame, or some that would bump into other cells and then turn around and swim off in another direction. Seawater is teeming with microscopic life, and bringing together our expertise from different areas of research stimulates our curiosity and interest in organisms other than those with which we are familiar.

Photo: Carina Bunse

Congratulations Dr. Ben! 

Recently, Benedikt Heyerhoff brilliantly defended his PhD thesis Ecological implications of marine viruses on host diversity, metabolism and the marine dissolved organic matter pool at the Institute for Chemistry and Biology of the Marine Environment, University of Oldenburg. His project focused on the role of phages for marine bacteria, their abundance in marine ecosystems, genetic composition, and lifestyle. He uses phage-specific signatures in metagenomes constructed from the Baltic Sea and a mesocosm experiment from the EcoMol Research Training Group to quantify their distribution and specificity in the marine environment.

It was a great joy to work together on the smallest life forms of the sea, in the EcoMol project and with Baltic Sea phages!

The Nord Stream leak

We recently joined two research expeditions onboard of R/V Skagerak to the southern Baltic Sea to study the extend and impact of the methane pipeline gas leaks for the planktonic ecosystem. We took several hundreds of samples that we are now processing in the lab for various parameters.

Ongoing projects

Response in plankton communities to methane increase

In a new project, we want to understand how plankton respond to elevated gas concentrations, in this case methane. Can the plankton communities buffer potential short-term harmful effects? Are bacteria quick to react when methane gas concentrations increase?

Plankton forms the base of the food web in the ocean and its productivity and biomass is important to support other organisms. Methane gas from biological activity is naturally present in some ocean regions, but here we want to look specifically at the mechanisms of what happens when large amounts of methane gas come into contact with surface plankton communities.

The project is funded by Aquacosm_plus and BalticWaters2030 and involves all together 15 researchers and students from the Department of Marine Sciences and the Department of Biological and Environmental Sciences at the University of Gothenburg, members from the Institute for Chemistry and Biology of the Marine Environment at the University of Oldenburg, as well as international trainees.

Small jars containing pankton
Photo: Carina Bunse

Effects of underwater gas leaks on plankton communities

The methane gas leaks near Bornholm in 2022 were one of the largest gas leaks potentially impacting the marine environment. The greenhouse gas methane is produced naturally through biotic processes, but the effects of such high concentrations on the sensitive ecosystem of the Baltic Sea are unknown. Some methanotrophic bacteria can oxidize methane, but their abundance in surface waters is usually low.

With this project I want to investigate whether the abundance and activity of methanotrophic bacteria increases in response to gas leaks. Ultimately, this knowledge will help to identify and shape possible responses to future gas emissions that can contribute to a healthier ocean.

The project is funded by BalticWaters2030 and Formas.

A green liquid is poured into an E-kolv
Photo: Carina Bunse

Carbon turnover of bacterial communities in the ocean

Biogeochemical models are powerful tools to assess how the large ocean reservoir of carbon influences and is influenced by the climate system. However, the high diversity of organic carbon compounds, microbial communities and their interactions is a challenge for modelling approaches. Here, we use controlled experimental conditions to disentangle the influence of microbial interactions on dissolved organic carbon biogeochemistry, by combining practical microbial experiments with a modelling perspective in a case study.

This project is a collaboration with Prof. Dr. Sinikka Lennartz, University of Oldenburg, Germany and funded by the Add-on fellowship for Interdisciplinary Life Sciences of the Joachim-Herz-Foundation.
More about the project: Biogeochemical Ocean Modelling

Pouring a green liquid into an E-colve
Photo: Carina Bunse

Linnaeus Microbial Observatory (LMO) - disentangling seasonal plankton dynamics

The Linnaeus Microbial Observatory, LMO, is a time-series station in the Baltic Sea Proper and the core of many research projects in microbial oceanography at Linnaeus University. Since many years, we collaborate on the topic of bacterioplankton community dynamics and links to dissolved organic matter turnover.
More about the station: Linnaeus Microbial Observatory

Bacterial communities change over seasons.
We know how seasons change in our gardens and how trees react to this. But also under the sea surface, seasons impact plankton and microbial communities. Different populations grow and thrive at different times of the year, contributing to dynamic patterns. Illustration: Carina Bunse


The MMEco Group is located at the Marine Department in Gothenburg. Here, we have sterile labs and thermal constant rooms that are ideal for our research. For larger experiments, we use the facilities of Kristineberg Center and the Tjärnö Marine Laboratory that offer excellent facilities for field work.

A sampling device is put into the sea to bring water samples on board.
Sampling at sunrise, a sampling device is put into the sea to bring water samples on board.
Photo: Carina Bunse