Marine snow Photo: Hanna Farnelid

Projekt: Marine snow - microorganisms and biological processes on sinking particles in the ocean

In the ocean, particles composed of aggregated biological and inorganic material are continuously produced and sink towards the seabed. These particles are referred to as marine snow. This project investigates marine snow from biological and biogeochemical perspectives. Our aim is to gain a deeper understanding of the microorganisms (with a focus on bacteria and phytoplankton) associated with marine snow, their activities (such as photosynthesis and nitrogen fixation), and how these microorganisms affect the amount of carbon and nitrogen that sinking to the sea floor.

Facts about the project

Project managers
Hanna Farnelid
Other project members
Lisa Winberg von Friesen, Christian Furbo Reeder, Linnéuniversitetet; Kristian Spilling, Finnish Environment Institute (SYKE)
Participating organizations
Linnaeus University, SYKE
Financier
Swedish Research Council (Vetenskapsrådets öppna utlysning 2023),  Marie Skłodowska-Curie Actions (Postdoctoral Fellowship program),  Royal Swedish Academy of Sciences (Biosciences scholarship)
Timetable
1 May 2024 – 31 October 2026
Subject
Ecology, Biology and Environmental Science (Department of Biology and Environmental Science, Faculty of Health and Life Sciences)
Research groups
Marine phytoplankton ecology and applications (MPEA)
Spetsforskningsmiljö
Linnaeus University Centre for Ecology and Evolution in Microbial model Systems (EEMiS)
Knowledge environment
Linnaeus Knowledge Environment: Water

More about the project

The surface ocean is bustling with microbial activity such as photosynthesizing phytoplankton and millions of bacteria and other microorganisms. Their activities result in clumping of cells, extracellular matter and inorganic particles, forming aggregates sinking towards the sea floor. Those particles are called marine snow and are often biological hotspots for e.g. bacteria. Depending on which microorganisms and processes acting upon a sinking marine snow particle, it can become remineralised (dissolved into its elements and reused by organisms in the water column) or sink to the bottom where carbon and other elements can be stored for longer periods of time. In the Baltic Sea, we currently have poor knowledge about marine snow from a biological perspective. Which phytoplankton contribute to the formation of marine snow and under what environmental conditions? Which bacteria colonize specific marine snow, and what processes do they perform on/in the particles? How much do specific microorganisms contribute to the storage of carbon in the sea floor?

We are investigating those questions in the Baltic Sea through sampling of marine snow at different locations, different times (seasonal variation) and with various methods. We use, for example, sediment traps and apply different molecular tools, microscopy and stable-isotope approaches. The knowledge generated in this project group is important to understand the carbon and nitrogen cycles of the ocean, and for generating a better resolution of the microhabitats for microorganisms in the ocean.

You are very welcome to contact us if you are interested in collaborating, performing a student project, or have questions.

The project is part of the research in the research group Marine phytoplankton ecology and applications, in Linnaeus University Centre for Ecology and Evolution in Microbial model Systems (EEMiS) and in Linnaeus Knowledge Environment: Water