‘Hola’ from the westernmost tip of Europe: Galicia.

Abel enjoys the breathtaking view from our sampling point across the Atlantic to the National Park of the Cies Islands. 

Hola, ¿qué tal? We, Svea and Abel, are Team Spain.

We are in the northwest of Spain in the region of Galicia, more exactly in Vigo. A city with about 300.000 inhabitants, located next to the Atlantic and surrounded by beautiful nature. Galicia is definitely an underestimated region in Spain. Very diverse, with amazing views from mountains directly onto the sea. You can find crystal clear water in hidden bays, the islands of the Atlantic National Park, and Santiago, which is the aim of many pilgrims walking through Spain and even Europe to reach the Cathedral of Santiago.

It was quite an up and down until we found each other and Svea could explore all these great places, but let’s start at the beginning.

After the course in March and the time waiting in April due to COVID, Svea could arrive in Vigo at the beginning of May. Finally, here, she was able to verify that in Spain not every day is warm and sunny, we could even say that during the first months our most common garment was the raincoat. Good that Svea was used to rainy days (from northern Germany) and we had a lot to work on anyways.

Even on rainy days there was always something to discover.

Choosing tanks, buying stuff for the aquarium, setting up the lights, finding shelters, building the behavior measurement structure… a lot of work! Really exhausting, but it was easier to cope with it together than it would have been if working alone.

With everything prepared, we could start with the pilot studies. Would the red light affect our animals? How many replicates would we need to obtain significant differences? Let’s check!

The laboratory set up of the sea urchins including oxygen supply, shelter and food pellet in individual tanks.

Svea worked with sea urchins (Parancentrotus lividus).

Sea urchins live in large numbers in the rocky intertidal and subtidal and can be found in rock pools during low tide. Their bodies are all covered with spines, which they use as a protection against predators. In this way, they seem to possess an impenetrable armor, but they have a weak point, which is the bottom where the mouth is. So, the best way to collect them from the pools is to fork them up. Sea urchins like to stay in holes in the rocks, which are their home places, and this sometimes makes the collection more difficult, because the sea urchins commonly have nearly the same size and shape as the holes.

Sampling sea urchins in intertidal rock pools was always very colourful.

Abel worked with dog whelks (Nucella lapillus). Dog whelks are predatory snails from the intertidal, they prey on invertebrates with calcareous shells like other kinds of molluscs (limpets, mussels…) or on barnacles. Small but bullies! For that, they use a toothed structure to make a hole in the shell of their prey, then they inject a substance with digestive enzymes through the hole. This turns the soft body of their prey into a “soup”, which the snails will suck out with their proboscis. Mmmm… Buen provecho!

A dog whelk attacks a mussel in the field.

When starting with the lab work, we met the first challenges: Sea urchins like to place the food pellets on top of their body like wearing a hat rather than eating them and the Nucellas are expert escapists. We looked for a solution for these issues and tried different things. Finally, we designed a structure to fix the pellet to a stone and an anti-escape system by cutting a mesh and placing it on top of the aquarium.

On the right food pellets fixed to a stone and on the left an anti-escape system with mesh on top of the aquarium for the Nucellas.

With time we gained experience in handling the animals and our pilot studies showed that red light had no effect on the consumption rates of the test organisms. In the IIM-CISC institute, we had a helpful team, with whom we discussed our results and decided on the last open questions for the setup of our main experiment.

While collecting Svea was measuring sea urchins to take a certain size range back to the lab.

Svea enjoyed the field trips the most. The view across the sea to the Cies Islands from the beautiful rock pools, where we collected our sea urchins, is stunning and the weather was kind to us in July and August. But on sunny days, we had to work fast to get the sea urchins to the lab before they got too hot. Most of the time our Spanish supervisors joined the field trips and helped to collect and identify the organisms. Besides, we could ask them anything and learnt from their great knowledge about algae or invasive and intertidal species.

Teamwork – our supervisor Ignacio enjoyed coming with us to the field.

After nearly two month of preparation, we finally started the first main experiment in July. 

Meanwhile, we stayed contact with the other teams in our weekly meetings via Zoom. The discussions focussed on the experimental set up, and problems we were facing or the vaccination status of the team members. It was nice to share the open questions and uncertainties with the others.

By the end of the first experiment, we had the individuals’ consumption rates data and had to analyse 3456 pictures of the activity patterns. This was a lot of work…

Because we found no significant difference in the consumption rates of neither the sea urchins nor the snails, we decided to do a second experiment without acclimating the test animals to the light conditions in order to investigate their reaction to an acute change in the light regime. This way, we also needed less time for the second experiment than for the first and could finish it by the middle of September.

Coming closer to the end of summer, all of us were getting more and more curious, if it would be possible to meet in person for our data analysis course… After weeks of waiting and hoping GAME coordinator Mark Lenz had good news for us!

All teams will meet in October in Kiel to analyse and interpret the data. We are really looking forward to meeting all the other participants and exchanging stories and experiences from different countries (and this time not only with regard to the experiment). It will be great to have a drink together and get to know each other. And maybe after the course, we can all order a beer in at least 6 different languages.

Adiós y hasta pronto en Alemania

Svea and Abel

Bye bye Vigo – hope to see you again soon.