The September blogpost is the internship report from Felix about his student internship at GEOMAR, with a brief insight into Lea’s perspective, who supervised the internship. The blog is published in German anf English.
During my two-week internship at GEOMAR in July/August 2025, I gained comprehensive insight into various areas of marine science work – from laboratory analysis and sample preparation to practical activities on board a research vessel.
Topic Focus: Sampling the Sea Surface Microlayer
One of the main focuses of my internship was studying the sea surface microlayer (SML) – the uppermost layer of the ocean, just one millimeter thick, which plays an important role in the exchange of substances between the atmosphere and the ocean. I familiarized myself intensively with various sampling methods, in particular the glass plate method. A glass plate is immersed vertically into the water. When it is slowly pulled out again, only the SML sticks to the glass and can then be transferred to a sample bottle using a squeegee and funnel. Preparing the laboratory involved cleaning a tank, the glass plate, the squeegee and glass containers, assembling the test equipment and making labels to identify the samples.
Practical Work in the Lab
A significant part of the work consisted of preparing and following up on sampling. This included filling bottles with high-purity (Milli-Q) water and preparing a saturated salt solution to produce artificial seawater. I also filled vials with artificial seawater, sealed them without leaving any bubbles, and then injected 5 mL of helium into the sealed vials to create an air-free gas phase in the vial. They were then mixed with a standard to test the new autosampler for methane. Methane is separated from other gases in the sample by gas chromatography (GC) and measured by a flame ionization detector (FID).
I also helped clean transport boxes that had been returned from a cruise. These were then refilled with sample vials. After that, I numbered unlabeled boxes with spray paint and marked them with colors.
I was also allowed to help test sensitive measuring instruments in the CO₂ laboratory.
Physical Oceanography and Technical Work
The day spent in the Physical Oceanography working group and at the Technical Logistics Center (TLZ) was also particularly interesting. Here, I took on manual and technical tasks such as soldering components and partially dismantling a glider – an autonomous underwater vehicle that collects data in the ocean over long periods of time. The glider was then prepared for repair and shipped off. Finally, I was allowed to try out how an Arduino works and write a little code myself.
Day Trip with Alkor
A particular highlight was my participation in a day trip with RV Alkor. The aim was to recover a buoy that had been deployed in the Baltic Sea for testing and will be used to collect data off Cape Verde in the future.
Resume
The internship at GEOMAR gave me deep and varied insights into how modern marine research works. From precise sample preparation in the lab to technical work in the TLZ and practical application at sea, I was introduced to the entire spectrum of oceanographic research. The experience showed me how interdisciplinary and diverse this field of work is – and how scientific precision and technical expertise work together.
The internship reinforced my desire to pursue a career in science. Although I don’t know exactly which field I will ultimately choose, the experience has shown me that research allows me to combine a variety of interests and offers me numerous career prospects.
I would like to thank GEOMAR for this opportunity, especially the Chemical Oceanography department, where I spent most of my time, and my supervisor Lea Lange.
Felix
Supervising an Intern from (almost) High School
Felix had applied for a voluntary internship with GEOMAR, like 84 other pupils. Only a handful get invited. He is currently finishing 10th grade in school. Originally, I had planned and invited him to help me with a two-week-long experiment. But unfortunately, I had to cancel it on short notice in favour of polishing my first paper. It was a challenge for me to come up with other things for him to do on such short notice. In the end, it worked out well because he was honestly broadly interested, curious to understand our work and easy to work with, so he could be passed around without worries. My colleagues, who jumped in for me while I was sick in the second week of the internship, reported only good things. I feel like I lost a lot of time while he was in our group, but honestly, it was the sickness that threw me back. Not the supervision. I am pretty sure that already in the second week it would have paid off. He knew his way around the building and team by then, he knew the hazards, the methods, and didn’t mind doing whatever came up. He didn’t even mind if there were times with nothing to do, but watching things being done.
At the moment I decided to invite a pupil as an intern, I was aware that it might turn out to cost more time than the support I would receive. I wasn’t really worried (after all, Felix didn’t have to do this internship), but curious how it would go. And definitely confident that without help, I wouldn’t be able to perform my experiments and in turn, that it would be very insightful and interesting to someone from school to participate full-on. I was worried whether Felix would enjoy the internship without the experiments. But actually, this way, I think, he got much better insights into our „science job“ (and still wants to become a scientist). And next to the enjoyable working together feeling and sharing the nerdy stuff in full depth, also some of my tasks, that I never find the time to do (like painting the boxes), are done!
Lea (PhD)