Phytoplankton are responsible for up to half of the oxygen production on the planet. A lot of this newly fixed carbon passes through bacterial respiration, giving a key step in cycling in the ocean. Metabolites released from phytoplankton are the ocean currencies, and this project aims to identify and quantify this important step. Under various environmental factors, e.g. elevated CO2 and temperature, in addition to nutrients conditions, we aim to look closer into how this will affect the metabolite composition in the phytoplankton as well as released and assimilated by bacteria.
The Swedish coastline has a salinity stretching from only 2 in the north up to full salinity in the west. This coastline has a long history of monitoring, from monthly to weekly during the whole year. We have used monitoring data for the Baltic Sea to look at trends in nitrogen fixation, biomass and community composition of filamentous cyanobacteria. In addition, to reveal seasonal trends in biodiversity as well as long term trends in phytoplankton diversity and community composition, from low to high salinity regions. Read the most recent publication in Harmful Algae here.
During my PhD I was involved in various projects using secondary ion mass spectrometry to reveal single-cell nutrient assimilation of carbon and various forms of nitrogen (N2-gas, nitrate and ammonium). This was conducted by using stable isotope incubation experiments both in the field and under laboratory conditions. We revealed single-cell assimilation in natural mixed communities but also in newly hatched hundred years old diatom cells. Feel free to read some of the publications.
With starts as a bachelors student, continuing as a phd student, and also now after I have been part of projects working with the diatom Skeletonema. This is a common and important bloom forming species around Sweden. It form resting stages in the sediment which can be used as a “time-machine” when hatched in the lab, and how they can survive for more than hundred years is this stage is something that is still puzzling for scientists, we have indications on parts of the answer in one of our resent publications.