»Unsere Arbeit hilft, das Meer zu schützen.«
Kerstin Jochumsen
Why the ocean?
I actually wanted to work in forestry, but because of my allergies and nearsightedness, I ultimately decided against it. So I thought, if it can’t be the forest, then the ocean – you won’t find any pollen there. So it was a fairly pragmatic choice, combined with curiosity: There are very few blank spaces left on the map, but the ocean can still surprise you.
How has your connection to the ocean changed over the years?
It’s still an important part of my life and I enjoy spending time there. But when you work on a research ship, the whole thing loses a bit of its romance. It’s stressful work, often done in bad weather. The notion of gazing out at the water in wonder simply isn’t realistic. Most of the time, the weather is more important than the view. But on every voyage, there have also been plenty of moments in which I was very thankful to be doing the work I do.
You’ve been working at the Federal Maritime and Hydrographic Agency of Germany (BSH) since 2018. What is your work like?
The BSH is the most important maritime agency in Germany and part of the Federal Ministry of Transport. We monitor the North Sea and Baltic, conduct marine research, and are internationally networked. I started at the BSH as head of the sub-division Sea Ice Physics and Climate. We regularly take readings in the North Sea and Baltic – for example, on the temperature, salinity and oxygen content, and contaminants. The goal is to identify changes and trends, like those due to climate change. I’ve headed the Oceanography division since 2024, with other areas like storm-surge forecasting, the chemical lab, and geology. Today my tasks are mostly strategic: staff, budgets, data quality, and political consulting.
Why is this work important for society?
To be able to issue warnings for things like storms or storm surges, we need real-time data. We observe long-term trends so that we can better gauge the scope of climate change and plan adaptation measures. At the same time, the ocean is heavily used: shipping, offshore wind parks, pollution. Our readings help protect the ocean and to develop measures for climate change adaptation.
Have there been any big surprises in your research career?
Early on, back when I was doing my Ph.D., I realized that ocean models didn’t actually reflect physical processes in the ocean as well as we assumed. Or, on some fundamental points, that they were simply wrong. I was amazed because I’d always assumed models were the way to find the truth. Later, on a project between Iceland and the Faroe Islands, we investigated the exchange of heavy water near the seafloor. We assumed that water from the north was flowing into the Atlantic – but our time series showed: The water just moves back and forth, there is no actual exchange at all. It surprised us, but the data was clear.
Was there a discovery that especially moved you?
After storms over the Baltic in June and October 2023, you could see in the satellite data and time series how the sea changed near the coast. Due to the wind, cold, nutrient-rich and oxygen-poor water was transported up from the deep. In response, the surface water rapidly cooled in June, in some places by more than 10 degrees, and in October the hypoxia led to fish die-offs. I was familiar with events like these from the South Atlantic, but to see them on such a small scale and with direct consequences in the Baltic definitely left an impression on me.
Sie sind Mutter von zwei Kindern. Ging das immer gut mit der Wissenschaft zusammen?
Ich habe mir die Elternzeit mit meinem Mann geteilt. Längere Auszeiten sind im Wissenschaftsbetrieb schwierig, weil man den Anschluss an Projekte und Kontakte verliert. Gerade an Unis und Instituten, die sehr projektbasiert arbeiten, ist alles schnelllebig. Wenn man zwei Jahre raus ist, ist man oft nicht mehr gefragt. Das ist unfair, aber Realität. Es hilft, wenn man die Betreuung auf mehrere Schultern verteilen kann.
Wie erleben Sie die Geschlechterverhältnisse in Ihrem Fach?
In der Meeresphysik gibt es viele Frauen, aber Leitungspositionen sind oft noch von Männern besetzt. Zu den Karrierehindernissen für Frauen zählen befristete Verträge, insbesondere dann, wenn man eine Familie hat oder plant. Netzwerke sind dabei wichtig. Männer sind da oft besser aufgestellt, weil sie sich mehr Zeit für informelle Treffen nehmen. Das ist kein böser Wille und Frauen werden nicht absichtlich ausgegrenzt, aber es macht einen Unterschied dabei, neue Projekte zu entwickeln und Partner zu finden. Es ist wichtig, Kontakte zu knüpfen und nicht nur im Homeoffice zu bleiben.
Gab es für Sie ein Motto, das Ihnen geholfen hat?
Nicht zu viele Aufgaben gleichzeitig annehmen, sonst verzettelt man sich. Aber auch nicht nur auf ein Thema spezialisieren. Ruhe bewahren, wenn mal etwas nicht klappt. Offen kommunizieren, daraus lernen, weitermachen.
Was würden Sie jungen Forscherinnen raten?
Durchhalten. Viele sind schnell frustriert von der unklaren Perspektive. Wenn man lange genug dabei bleibt, ergibt sich meist etwas. Sich nicht abschrecken lassen, auch wenn es lange nur befristete Verträge gibt. Und: Wenn man Kinder möchte, sollte man es wagen – sonst bereut man es später vielleicht.
In many cases, not enough is being done to protect the ocean. How do you cope with that?
It takes patience. It often takes years before anything changes, especially when it comes to international processes. But you can see progress – for instance, the insecticide DDT is now barely detectable in German waters because it was banned in the EU.
What makes you optimistic when it comes to climate change?
There are cities like Hamburg, where the problem has been recognized and measures are being taken – the Climate Advisory Council, sponge city concepts, promoting more cycling. It may not be happening as fast as I’d like, but at least something is happening. In other regions, this is harder.
Is there a research question on the ocean that you most want to find the answer to?
What’s the most effective way to restore a healthy ecosystem in the North Sea and Baltic? We still know too little about how the various human influences on climate change interact. We won’t be able to fix everything, but what would do the most good? And what will the ecosystem look like when temperatures and salinity continue to change? Species migrate – new ones arrive, others disappear. I’d love to know what the ocean will look like 200 years from now.
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Dr. Kerstin Jochumsen, born in 1978 in Hamburg, heads the Marine Sciences department at the Federal Maritime and Hydrographic Agency of Germany (BSH) in Hamburg.
