Royal Netherlands Institute for Sea Research

Marine Viral Ecology

Viruses are numerically the most abundant entities in the world’s oceans. With microbes forming >97% of the biomass in the oceans, microorganisms are the most important hosts producing these viruses. Viruses have been shown to infect many different prokaryotes (Bacteria and Archaea) and eukaryotic phytoplankton. Viruses cause the release of host derived nutrients and organic carbon in the water column, thereby affecting biogeochemical cycling and the efficiency of the biological pump. The impact of viruses on microbes, also in relation to grazing, depends on the abiotic and biotic environment. As this process works both ways, the viral component of the marine microbial food web is regarded as an important feedback system in climate change processes.

At the NIOZ Marine Viral Ecology lab we are study the ecological importance of aquatic viruses in terms of impact on host population dynamics, biodiversity and biogeochemical cycling. For example, we measure viral lysis rates in the field and first data show that viral lysis is an important mortality factor for phytoplankton as well as bacteria and can be as high as the more traditional mortality by grazing. We translate our findings to biogeochemical fluxes (C, N, P) in order to understand how viral activity affects food web structure and efficiency. Our research brings us to seas and oceans worldwide, from the North Sea to the Atlantic Ocean and both the North and South pole.

We also study the interaction of marine viruses and their hosts in relation to their environment. We isolate and bring into culture new viruses (and their host), characterize them using standard virology and molecular methods, and use the virus-host model system for experimental studies. A main focus is what the influence of environmental factors such as temperature, nutrients and CO2 on the production of these viruses. We also focus on different factors that may affect the survival of viruses, thereby directly affecting the impact viruses have in their environment.


If you are interested in working on this fascinating research topic with us, you are welcome to come and discuss various opportunities. You can work with many different laboratory techniques, such as culturing of phytoplankton, bacteria and their viruses, flow cytometry, (epifluorescence) microscopy, PAM fluorometry, molecular techniques. Projects (preferably min. 6 months) can start throughout the year. Our target group are primarily MSc students, but students of other study levels can inquire, too.


If you are interested, please contact Prof. Dr. Corina Brussaard ( 

New website for NIOZ

This year we are going to redesign and technically improve the NIOZ website. We would like to take your opinion as website visitor into account.

By answering 10 questions you can help us enormously! It will take you no longer than 4 minutes. You can win a NIOZ t-shirt and a book voucher to the value of EUR 25 if you fill in the questions.

Thank you for your help!

No, sorry! Yes! I'll help out!