From the Baltic to the Bench: Ulyana Pena Samples for Microplastics
Heading to the Baltic
On November 7, PML collaborator Ulyana Pena of the University of Colorado Boulder and Science in the Wild sets off for northern Europe, and she is taking our microplastics work with her. From November 14 to December 3, she will sail with the PONANT Science program aboard Le Commandant Charcot, collecting seawater samples from the Norwegian coast to the far reaches of the Baltic Sea. Those samples will come back to our lab in Charlotte for analysis. Science in the Wild is a participatory science initiative that runs field expeditions around the world built on education, research, and adventure.
I am proud of this one. Some of the most valuable science we do starts with someone willing to stand on a cold, pitching deck in November and filter seawater carefully, sample after sample. Ulyana is that person, and our lab is lucky to have her as a partner.
The ship and the route
Le Commandant Charcot is a 150 meter Polar Class 2 icebreaker with a hybrid LNG and battery power plant, operated by PONANT since 2021. It is the flagship of PONANT Science, a program launched in 2021 that brings researchers aboard expedition voyages to reach waters few labs can sample on their own. The ship carries two onboard laboratories, which makes it an excellent platform for careful water sampling.
The voyage begins in Bergen, Norway, and runs south past Stavanger and the Lysefjord to Kristiansand. From there it rounds Skagen at the northern tip of Denmark, passes through the Danish straits, and enters the Baltic, calling at Visby, Stockholm, and Tallinn before reaching Helsinki.
A second leg then loops through the Baltic from Helsinki to Stockholm, Visby, Gdansk, Riga, and Tallinn, returning to Helsinki. Together, the two legs span the Baltic Proper and reach into the Gulfs of Finland and Riga.
Why the Baltic matters
The Baltic is one of the most useful places on Earth to study plastic pollution. It is a shallow, semi-enclosed, brackish sea bordered by nine countries, with a large, densely populated watershed draining into it. Water exchanges with the open ocean only slowly through the Danish straits, so what enters the Baltic tends to stay there.
That makes it a natural laboratory. Particles from rivers, cities, shipping, and fishing all accumulate in a system small enough to sample meaningfully. For a microplastics lab, samples from the Baltic offer a valuable contrast to the open ocean and Arctic waters we have sampled before.
From seawater to the lab bench
Ulyana will collect water samples along the cruise track using Niskin bottles, which seal a discrete volume of seawater at a chosen depth. Because the route runs from the North Sea coast of Norway, through the Danish straits, and deep into the Baltic, the samples will capture a gradient from salty open water to the brackish, enclosed inner sea. Once the samples reach PML, our team will isolate and characterize the microplastic particles they contain: how many there are, what polymers they are made of, and what they look like.
That last question is where our lab has focused much of its recent effort. Our work suggests that a particle’s geometry matters for its biological effects, not just its size or chemistry. Fragments that break apart along jagged fracture lines may behave very differently from smooth spheres or fibers. Using image analysis and shape descriptors such as convexity and solidity, we can quantify those differences and connect them to toxicity.
Baltic samples will let us ask whether the shapes we find in an enclosed, heavily used sea differ from what we see elsewhere. Our Ph.D. student Md Shah Nawaz Arafin, who leads our microplastics and PFAS sampling, will work with the new data alongside our existing ocean datasets. The Baltic results will also be added to GOCOS, our open-source platform for monitoring PFAS and microplastics across the world’s oceans.
Science travels on partnerships
No single lab can sample the whole ocean. Our microplastics program reaches as far as it does because collaborators like Ulyana carry our protocols into waters we could not reach on our own. Every bottle she fills extends our map a little further.
Thank you, Ulyana. Fair winds and following seas. We will share what we find once the samples are back in Charlotte and the analysis is done.
