Hi! My name is Kasia Piwosz and I am a professor at the National Marine Fisheries Research Institute in Gdynia.
In my work, I study ecological relationships between microorganisms living in sea water.
Microorganisms are wildly diverse.
The number of protozoan species is estimated at several to several million,
and bacteria even trillion.
However, describing new species is very difficult due to their small size.
You need a really good microscope to observe the beauty and see the details of the structure.
Therefore, the discovery of the true biodiversity of microorganisms was only possible after the development of molecular methods.
Today, in evolutionary and ecological research, the entire DNA of organisms is sequenced.
By comparing the obtained DNA sequences, phylogenome trees are built that have hundreds of branches.
Most life on our planet is invisible to the naked eye.
But that doesn't mean it's invisible.
If all organisms living in the seas and oceans were weighed, 70% of the weight would be microorganisms.
If all marine microorganisms were combined to form people, there would be over a million times more than there are on earth today.
Half of the oxygen we breathe is produced by microorganisms that live in the seas.
Unicellular algae that fix carbon dioxide form the basis of the trophic pyramid in the sea.
Half of their production is eaten directly by tiny crustaceans (zooplankton),
which is fish food.
The other half, on the other hand, is secreted directly into the water column, either as a result of stress or as a result of cell disintegration.
This released matter is inaccessible to animals.
However, it can be used by bacteria.
Bacteria, in turn, are food for protozoa,
which are food for larger protozoa,
which are food for even larger protozoa.
The largest protozoa, which actually reach the size of hundredths of a millimeter,
can be eaten by crustaceans
which are food for fish.
This closes the microbial loop in the sea.
Microbial food webs are at the center of my scientific interests.
My research focuses on the role of protozoa in the carbon flux in the ecosystem
and on the impact of microplastics on organisms.
The implementation of this research is possible thanks to two projects funded by the National Science Centre.