In August this year I got the chance to work at the Tjärnö Marine Laboratory of the Gothenburg University with the evolutionary biologist and genetics expert Erica Leder, a professor in the Department of marine science. Tjärnö is an Island at the northern Westcoast of Sweden close to Norway. The lab itself is part of the university’s research facilities, located in the most species-rich area of Sweden, next to Kosterhavet National Park, Sweden’s only marine national park. Around 70 researchers live there all year long, accompanied by visiting school classes, university courses and many master students working on their thesis papers.
My work was mostly about Littorina Saxatilis, a very common snail species all over Europe. This species is divided in two ecotypes. This means that they´re evolved differently, but genetically they still are considered the same species and able to mate with each other. The crab-ecotype, lives in rocky parts of the coast, where lots of crabs live. Thus being quite big, they have a thick and strong shell and react very sensitive to any movement around them. The wave-ecotype on the other hand lives on boulder shore, where it is important not to be washed away by crashing waves.
Through the process of speciation these ecotypes will diverge into different species. Hybrids between both ecotypes are automatically less adapted in either environment and more vulnerable. This kind of hybridization can be avoided by simple distinguishment in habitat choice but also through mating preferences. We wanted to find out how exactly this assortative mating works.
A female Littorina saxatilis can store the sperm from different males. We tried to create some kind of timeline according to the age of the offspring from individual females to find out, if there is some kind of algorithm or similarity in their genes. Here, I actually got to do the hands-on work. We went out collecting the snails (Bild 3) and Erica showed me how to properly dissect a snail under the microscope and remove the shell without mangling it completely. (Bild 4)
I also learned how to differentiate female and male and how to cut off the brood pouch without opening it directly to open it later on in a different petri-dish and sort the offspring by age with a pipette. It is amazing how different the stages actually are (Bild 5). Some eggs only have one or two cells in them and some baby-snails were already crawling around fully developed. Sadly, I wasn’t there long enough to get some real results because the gene extraction was quite difficult. It was hard to find the right method to digest, especially because there is hardly any DNA in the little snails and we had to let them grow and develop without losing our timeline. (Bild 6)
Apart from this highly interesting main work, I spend time aboard the research-ship “Nereus” along a swedish high school class that went out sampling different animals for some experiments. With a mini trawling net we caught several species, from coldwater-corals, to sea stars, crabs, mussles, barnacles and even one fish. (Bild 7, 8, 9) To be able to touch all of these animals, to feel their texture and to be able to observe their behaviour from such close up was extremely fascinating. I also got to join the biodiversity course from Gothenburg university one day. First, we spent the afternoon identifying frozen fish to learn how to work with the identification keys. (Bild 10) During the next morning we went out to catch some fish right in front our doorstep on Saltö, mostly goby fish, but also eel fish and even three flatfish. We also got the opportunity to snorkel and watch them and some crabs in the water.
The lab provided free snorkelling-tools for everyone at the station. And although the sight wasn’t exactly perfect, it’s extraordinary what you can find in the water if you only take a closer look. (Bild 11-14)
Swedens Westcoast has a lot more to offer apart from what’s underwater. It is also known for its beautiful and wild landscape. I would encourage everyone to embrace it as much as possible. The forests are completely different from those in mid-Europe. Unlike nowhere in Germany you will find stone formations and huge stone fields everywhere. Additionally, there are lots of blueberries and mushrooms to be found from July till September. (Bild 15)
During my whole stay I lived in the so called “white house” on the lab grounds together with all the master students. For two weeks I could join their incredible community, which felt just like a family. They told me all about their work and invited me to their group activities, like snorkelling on the weekend and even a night dive to experience the bioluminescence. This was probably the most fascinating thing I have ever seen in my life. As soon as anything moves in the water the particles lit up. We watched it several nights in a row until the current washed it out to the ocean again. You could literally swim through an explosion of light. Waves or the touch of your hand was enough to start the spectacle. The algae even stuck to your hand when you took it out of the water. The fascinating thing is that nobody knows why these algae are bioluminescent. In daylight they have an auburn colour and they only get bioluminescent if there was enough sun during the day. (Bild 16)
I am half Swedish myself, thus the Swedish culture comes quite natural to me. But something that I still wasn’t used to is “Fika”, which is best translated as coffee time. Every day at 10am and 3pm the whole lab meets up in the cafeteria and there is free tea, coffee and fruit for everyone.
Overall, I had a fantastic time and I could have easily stayed some more weeks. Thanks to everyone who made my time at Tjärnö Marine Laboratory so unforgettable!
Useful Tipps:
- Don’t worry about language, I heard almost as much German and English at Tjärnö as Swedish. It’s a very international university so you will meet people from all over the world.
- Bring enough food! Since the next town, Strömstad is about half an hour away by car and busses only go a few times per week and not at all on weekends, make sure you have everything you need.