Marine microbiology
Mesocosm experiment at the Espegrend Marine Biological Station (MBS)

Unlocking Emiliania huxleyi secrets

The first AQUACOSM group has arrived at UiB's Marine Biological Station. The international team of scientists are here to study the coccolithophore Emiliania huxleyi.

The mesocosm raft and our target organism E. huxleyi
Jorun K. Egge

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The sun is shining, and right now, everything is busy at Marine Biological Station (MBS) in Bergen, Norway. This is because the first AQUACOSM group has arrived at the station to carry out a mesocosm experiment. As many previous visitors this group of internationally renowned scientists wants to pick up even more secrets from the coccolihophore Emiliania huxleyi.  This cosmopolitan unicellular algae forms massive oceanic blooms covering thousands of square kilometres, and because of the calcium carbonate scales covering the cell surface, and its chemical composition, such massive production can have a significant impact not only on the properties of the surface mixed layer, but also on global climate.  Researchers in Bergen were among the first ones to detect and identify viruses that infect Emiliania huxleyi. The research environment in Bergen also have a long tradition and great experience in performing mesocosm experiments. This is why Assaf Vardi and his team composed of twelve scientists from Israel, USA, and Spain applied for transnational access at MBS and planned a project called VIMS-Ehux:  The crosstalk between viral infection and microbiome succession during an Emiliania huxleyi bloom, and its implication for the biogeochemical S and C cycles. A holistic approach.

Since Assaf and co-workers first planned the project, the team has grown with scientists from “the Bergen team” as well as scientists attending from abroad without support from AQUACOSM, and now amounts to approximately thirty scientists.

As the project title suggests we will try to induce a bloom of the coccolithophore E. huxleyi, (which can been seen on the photo), and we hope to follow the build-up, the culmination and the decay of the E. huxleyi bloom over the 4-5 weeks the experiment runs. Some of the aims we have for the experiment are to:

  • Quantify the extent of active viral infection during the bloom using sophisticated biomarkers
  • Characterize the possible trade-off between E. huxleyi susceptibility to both viral and bacterial infection
  • Unravel how  host and virus “communicate” via extracellular vesicles and info-chemical signals (e.g. DMS, sugars, sphingolipids)
  • Examine how E. huxleyi-EhV interactions determine the metabolic and chemical composition of particulate and dissolved organic material
  • Determine the composition of biological aerosols (viruses, bacteria, coccoliths) as function of the bloom

We are looking forward to a crowded MBS with high scientific activity in the next weeks!


The VIMS-Ehux mesocosm experiment is funded by the AQUACOSM project (EU H2020 – INFRAIA 73106) in the framework of AQUACOSM Transnational Access (TA) scheme.

By Jorun K. Egge (professor) and Tatiana Tsagaraki (researcher) at University of Bergen and Aud Larsen (principal scientist) at Uni Research Environment.