Olá da Madeira! The island – a green paradise in the middle of the Atlantic Ocean – has been home to us for almost three months already. How the time flies!
We are Lara and Karo, one of 8 teams that currently conduct experiments all over the world as part of this year’s GAME project. Lara is a Marine Biology student currently enrolled at the University of Rostock and she is collecting data for her master thesis within the project. When she heard about GAME from her professor, she knew she had to be part of it! Karo is studying Biological Oceanography in Kiel. She found her passion for marine sciences quite recently and has never lived close to the ocean on beforehand. It was a dream of them both to join this project!
This year’s aim is – like in the previous years since 2021 – to investigate the effects of artificial light at night (or ALAN for short). We want to see how this phenomenon affects macroalgae in their ability to photosynthesize, grow and defend themselves against grazers. After an intense planning phase in March, during which we decided on the design of our experiments, we were more than glad to leave cold and grey northern Germany behind and escape into the sunny, subtropical climate of Madeira.
Finding accommodation was not easy, but in the end, we found a nice flat in the capital city Funchal with (almost) an ocean view! More than this, we have a balcony where we’ve enjoyed many lengthy weekend breakfasts.
We had an enjoyable first week when we settled into our flat, scouted the city and tried to figure out the bus system, which proved to be kind of complicated, since there are so many different bus companies here. One thing we learned very quickly, though: walking on this island requires strong calves. Madeira is hills…hills…and more hills. This is why you hardly ever see local people walking here – sometimes you get funny looks when you are doing a typical German “Spaziergang” (which is more like a hike over here), and you really have to watch out not to get run over by a bus or a car.
Then, we finally met the team of the Marine and Environmental Science Centre “MARE”. In our first meeting, we sat together with our supervisors (who are all former GAME participants!) and discussed how we could make our experiments here successful. Everyone was excited and motivated to get our project started!
Not long after, we made our first trip to the laboratory where we are conducting our experiments together. It is located in Quinta do Lorde, a place on the easternmost part of the island. It is close to the peninsula “Ponta de São Lourenço” which offers stunning views over the rugged coastline of the volcanic island. This part of the island is very dry and it almost feels like you have stepped into a desert – quite the contrast to the rest of Madeira, which is a lush, green paradise.
It is also the perfect spot for investigating ALAN, since it is very isolated and therefore mostly uninfluenced by nighttime illumination. Hence, the marine life here is not already adapted to light at night. The only downgrade is: the lab is located quite far away from Funchal, where we live. Most days, we have to take a bus that takes the scenic route and drives 1.5 hours along the coast, up and down the hills. At least we are rewarded with pretty ocean views during the drive – or we go for a little nap, especially after a long day in the lab. Thankfully, we can sometimes catch a ride in the car with our supervisors.
In the first weeks, we worked hard to build up our experimental set-up. Thanks to the great work of former GAME students, our lab is already equipped with most of the materials that we need, so we could quickly set up a flow-through system to supply running water to our algae. But we celebrated too soon: The complete water system of the lab had to be cleaned with bleach due to some pesky epiphytic growth and that meant that we had to re-do the flow through system again from scratch. We patiently cut tubes, and more tubes and connected them with little plastic suppliers, which let out filtered seawater to each of our 72 experimental tanks.
To give our algae as much light as possible, so that they are able to happily photosynthesize, we decided to order more LED lamps. One thing we did not anticipate: Madeira is located in the middle of the Atlantic Ocean, around 1000 km from the European coastline (the African coast is actually closer!), so equipment can take a loooong time to arrive. We were lucky that our lamps arrived “only” 3 weeks later, but already we faced the next challenge: connecting our lights to the control unit, with which we want to regulate the light intensity that our algae will be exposed to, proved to be more difficult than we had previously thought. However, with the help of the lab technician Patrício we quickly found a solution!
When we weren’t diligently building our set-up, we spent our days snorkelling in different places on the south coast of the island, looking for algae “candidates” that we could use in our experiments. Easier said than done, because the waters around Madeira are depleted in nutrients and large macroalgae are rare to find. We quickly decided on using Halopteris scoparia, a brown macroalgae that is quite abundant in the upper subtidal and therefore possible for us to collect while snorkelling. Another (particularly interesting) candidate is Rugulopteryx okamurae, an invasive brown alga, that has first been introduced on the north coast of Madeira in 2021 and since then spread rapidly – it is even growing on the pontoons in the marina outside our lab. It could be especially interesting to investigate how this species reacts to ALAN in comparison to native algae.
Since we want to investigate how ALAN affects the defence capacity of our algae, we also had to find suitable grazers (=algae eaters). Our options were less than ideal: Should we use sea urchins (even though they are very hungry and consume our algae in too large amounts) or intertidal snails (even though this makes less sense ecologically, because our algae come from the subtidal). In the end, we decided on the sea urchin Paracentrotus lividus, which we can easily collect in the tide pools next to our lab. Did we say easy? – To get the hang of how to sample these little algae eaters took some blood, sweat and tears. Equipped with forks and buckets; after waiting for low tide to arrive, we wade into the tide pools and try to gently (or not so gently) persuade our sea urchins to come out of the holes in the rock that they like to sit in. We always take good care not to injure or stress them too much, but some unfortunately have already met their fate.
Before we could start with the main experiments, we had to test a few things. For instance, how much and when the sea urchins eat and how much the algae photosynthesize. To find this out, we carried out some pilot studies – more or less successfully. During one of our pilot studies all our sea urchins mysteriously died, probably after some contamination[LM1] [LH2] of the water. In addition to this, our method for measuring the oxygen production initially did not work, because the oxygen values we measured did not stabilize and photosynthesized waaaay too slowly despite looking perfectly healthy. After many hours of trial and error, we fortunately found a way that should allow us to accurately assess the oxygen evolution. For this[LM3] , we increased the light intensity to help the algae photosynthesize more quickly and also got a multi-position magnetic stirrer where we can put multiple of our containers with algae on simultaneously. A little magnetic bar keeps the water in the containers in constant motion, resulting in more stable oxygen measurements.
Furthermore, we have another nice tool available here. It is a PAM, which is short for Pulse Amplitude Modulation. Behind this rather complicated name lies a technology with which we can assess how well our algae are absorbing sunlight for photosynthesis and ultimately determine their health status. Because no one in the institute had used the device before, we had to do a lot of headache-inducing reading (the 200-page manual is not easy to understand) and carry out some test runs to get prepared for the measurements. Our weekly meetings with the other GAME participants became crucial for discussing challenges and brainstorming solutions together – so far this project has been a huge learning curve for the both of us.
Our lunch breaks we share with the lizards. Fun fact: there are more lizards than mice on Madeira! They are called Madeira lizards (Teira dugesii) and they are endemic to some of the Macaronesian islands. They are very curious creatures – especially when we unpack our food. They sometimes even like to jump on our feet, but you have to watch out that they don’t crawl inside your backpack, and you accidentally take home a new pet.
When we are not in the lab, we also know how to have fun (not that being in the lab is not fun). Madeira is an island full of amazing places and activities, and it’s a hiker’s paradise! There are a lot of different routes to explore, very famous are “levada” walks here. Levadas are old, narrow water channels that wind through the mountains. They were constructed to carry water from the misty mountains down to the drier parts of the island to water the crops of the farmers. You can walk along these levadas and enjoy the views over the island!
Besides doing a lot of hiking and training our calves, we have spotted some dolphins, explored different beaches, and even got swept up in the European Championships fever. Since Madeira is Cristiano Ronaldo’s birthplace, people here (young and old) are fans, and we joined the locals cheering for the Portuguese soccer team. Of course, we also had to try Madeira’s famous “poncha”, a traditional drink with rum and fresh fruit juice – typically lemon, orange, or – our favourite – maracuja. Another drink is Nikita, which is a mixture of pineapple juice, ice cream and beer. It tastes… well… interesting, as Karo’s face in the picture shows.
Madeira’s climate is perfect for growing all kinds of tropical fruits and other plants. What people keep as house plants in Germany, grows here in ditches next to the road, or in the size of trees – Monstera leaves get almost bigger than oneself! We also tried some fruits here that we have never seen before in our life. Our flatmate’s supervisor even has avocado trees in his backyard, which we sometimes get a share of – a luxury we will sorely miss back in Germany.
Another thing we learned here: you can never trust the weather forecast. In Funchal, situated on the south coast, the weather is usually pretty dry and sunny. However, it’s a different story for the North coast, where it rains more frequently, and temperatures are cooler. But even here on the sunny south coast, you never know what to wear. You could burn under the African sun or in the next second freeze from the wind, especially in the evenings, when the sun is already down. The onion-principle (a German favourite) really proves best.
We have been really enjoying our time here so far and we are sure by the end of September we will not want to go back to Germany. We have finished the first experiment and are soon starting the second one, we are excited to see what happens!
Lights, Algae, Action! Researching light pollution in the middle of the Atlantic
Welcome to Cádiz
When we arrived in Cádiz in April, we knew that we would be spending the next months working on an experiment about underwater soundscapes. What we did not yet know was how much of our time would be spent carrying equipment through the city, rebuilding experimental frames, solving technical problems and trying to convince various pieces of equipment not to end up at the bottom of the Atlantic.
Cádiz itself was a pretty good and beautiful place to start.
The city is located at the very tip of a narrow peninsula and is surrounded by the Atlantic on almost all sides. There are beaches almost everywhere, small streets leading through the old town, the harbour with its many boats and plenty of places where you can simply sit down and watch the sea. It did not take us long to understand why Cádiz is sometimes called La Tacita de Plata, the Silver Cup.
Our first evening was still fairly relaxed. After arriving and settling in, we went out together for a drink and explored a little bit of the city. It was a good introduction to our new home. The next morning, however, the relaxed part was over and GAME 2026 officially began for us.
Our project focuses on how underwater soundscapes may influence the colonization of hard surfaces by marine sessile organisms. To investigate this, we used standardized PVC settlement panels mounted on experimental frames and exposed them to different underwater soundscapes.
Over the course of the experiment, we monitored which organisms settle on the panels and checked whether the developing communities differ between the different acoustic conditions. The panels themselves were only 15 x 15 cm in size, but the frames, which were holding them while they were underwater, were much larger and required quite a bit of construction and preparation.
So, before we could investigate anything, however, we had to build everything.
Building the experiment
The first weeks in Cádiz were all about getting the experiment ready. Before the panels could go into the water, we had to prepare the equipment, rebuild the experimental frames and organize everything needed for the different parts of the experiment. Our setup consisted of large rectangular frames made from PVC pipes that carried the 15 x 15 cm settlement panels while they were in the water. In addition to this, we had speakers for the sound playbacks and ropes, buoys and weights that kept everything in position.
Although, there were frames left from a previous GAME project that was done in Cádiz, we decided to build new ones, which meant sourcing new material, cutting and assembling PVC pipes, preparing the panels and putting the different parts of the setup together. Some materials were bought locally, while others had to be ordered. This also resulted in one of our first small fieldwork adventures: transporting several metres of PVC pipes in a public transport bus through Cádiz was not exactly an everyday activity. We did not have a car at the time, and the large hardware store, where we bought some of the material, was quite far away, so getting everything back to Cádiz meant taking several buses while carrying long PVC pipes through crowded streets and vehicles. We bumped into things more than once, attracted a fair amount of attention and quickly realized that carrying several metres of PVC through a busy city is not as easy as it sounds. At one point, the combination of researchers, long PVC pipes and a local hardware store became what we jokingly refer to as the “Bus Hardware Store” episode.
Building the frames also taught us quite quickly that fieldwork rarely goes exactly according to plan. Some parts required a bit of improvisation and technical problem-solving, and when we reached a particularly stubborn technical issue, we even called Liam’s father in Germany for some additional advice. Although he was not directly involved in the project, his background in mechanical engineering and his experience with practical technical problems made him a useful person to call when we needed another perspective. A video call across Europe was not exactly part of the original plan, but it turned out to be a useful addition to our fieldwork toolkit.
At the same time as we worked on the set up, we were preparing the recordings of natural underwater soundscapes that would later be used for the experiment. For this, we built a deployment system consisting of a concrete-filled bucket, a wooden pole and a HydroMoth attached to the pole. The idea was simple: the heavy bucket keeps the structure stable on the seafloor, while the hydrophone records the surrounding natural soundscape above it. The practical part was considerably less simple. Several heavy loads of concrete had to be transported through Cádiz, and once the equipment reached the beach, getting the concrete-filled bucket into position was another workout altogether. We used a two-wheeled hand truck to move the heavy bucket across the beach and then into the shallow water. From there, we worked our way out by snorkeling and swimming, carrying and guiding the setup into position. The water was no more than about two metres deep, so there was no need for a boat.
The setup may have looked a little unconventional, but it was based on the plans we deleoped for recording natural soundscapes during the preparative course in March. After plenty of cutting, drilling, tying, carrying and assembling, the first major pieces of the project were finally ready. The frames were taking shape, the equipment was coming together and our first soundscape recordings were underway.
With the construction phase coming to an end, there was only one major question left: where exactly will we put everything?
When the plan changed
Finding a suitable experimental site turned out to be one of the more complicated parts of the project.
Our original plans involved a site in a nearby marina, but the situation changed when we were informed that construction work was planned close to the site. The associated noise would have interfered with the acoustic conditions required for our experiment, making the location unsuitable for our setup. We therefore had to move the experiment to a different location at relatively short notice. This meant adapting the setup and transporting the frames again. In the end, we found our new home at Puerto América, at the north-eastern tip of the city.
The change was a good example of how fieldwork can sometimes require a little flexibility. You can spend weeks discussing the experimental design, the set up and the site selection, but once you actually arrive at the water, there are always things that you could not have predicted from a map.
The new location gave us enough space for the experimental setup and allowed us to continue with the project. Hence, the frames were finally transported to Puerto América, weighted and installed.
Getting the frames into the water was actually much easier than building them in the first place. Once we had transported the frames to the harbour, we were able to get them into position and secure them relatively smoothly. The real challenge had been the preparation on beforehand: assembling the large PVC structures, attaching all the necessary components and making sure that everything was ready for deployment.
After weeks of preparation, the frames were finally in the water. The structures that we had spent so much time building on land were now ready to become the basis of our experiment.
From this point on, the focus shifted from building the experiment to monitoring what was happening around it.
Hydrophones, boats and one very expensive swim
Once the experiment was running, the HydroMoths became an important part of our regular monitoring. These small underwater recorders allowed us to record the acoustic conditions around our experimental frames and to measure the sound levels reaching the area of the experiment. This helped us to keep track of the underwater soundscape throughout the experimental period and to verify in hindcast what acoustic conditions the organisms on the settlement panels were actually exposed to.
Of course, regular monitorings also meant regularly getting the equipment in and out of the water. And this was when one of our more memorable fieldwork incidents happened. One day, Liam was alone at the harbour and had a fairly straightforward task: retrieve a HydroMoth, download the data and put it back into the water. Everything went well until the moment when the HydroMoth decided to make the last part of the procedure considerably easier for itself.
It slipped out of his hands and disappeared into the water.
We tried to retrieve it by diving down, but the visibility was extremely poor. Finding a relatively small piece of equipment underwater turned out to be much harder than expected, and despite our efforts, we could not recover it. It was certainly not part of the original plan, but fortunately, the experiment could continue. The lost HydroMoth has since become one of those fieldwork stories that is much easier to laugh about afterwards.
The regular monitorings also revealed how quickly conditions around the experimental site can change. One day, for example, we arrived at the harbour and found a boat parked remarkably close to our experimental setup, almost directly next to our buoys. Luckily, nothing was damaged and the boat did not cause any problems for the frames, but it was certainly an unexpected sight when we arrived.
Working in a harbour means that we are sharing the space with many other users, and sometimes the surroundings have a few surprises in store for us. Fortunately, most of them have been harmless so far.
From PVC panels to marine communities
The most interesting changes, however, did not happen above the water.
They happened on the settlement panels.
At the beginning of the experiment, the panels were simply pieces of PVC. We sanded their surfaces and standardized them so that they would provide suitable settlement substrates for marine sessile organisms. After deployment, there was not much to see.
Then the first organisms started to arrive.
During the first sampling events, we began to see the panels changing. Small organisms had settled on the surfaces, and the communities became increasingly diverse. Ascidians and bryozoans were among those colonizers that became particularly noticeable, together with worms, crustaceans and algae.
Suddenly, the panels that we had spent weeks preparing were becoming real pieces of habitat.
That was probably one of the most rewarding moments of the project. You knew exactly what a panel looked like before it went into the water. Then you retrieve it a few weeks later and had to figure out what has colonized it.
Some organisms were relatively easy to recognize. Others required a microscope, identification guides and considerably more patience.
Our supervisor was a huge help with this part of the project, especially when it came to identifying organisms that were less obvious at first glance. What initially looked like a small patch of something growing on a panel, could turn out to be an entirely different taxonomic group once you took a closer look.
And sometimes the organisms were simply fascinating to look at.
Despite the fauna and flora on the panels, we encountered small crustaceans, fish and other animals using the experimental structures as a habitat. One particularly photogenic shrimp even ended up on Liam’s hand during sampling.
The panels were therefore becoming more than just experimental units. They were small snapshots of the underwater world and the marine biodiversity around Cádiz.
The scientific question remained whether the different acoustic conditions influence the development of the communities. But before we could answer that, we had to document what was actually there.
And that meant sampling.
Sampling in the field
Our first sampling event made another aspect of fieldwork very clear: sometimes there is no perfect laboratory waiting for you at the harbour.
Since our experimental site was relatively far from the university facilities, we transported the equipment we needed directly to the field site by car. This included the microscope and the other equipment needed to examine, photograph and document the settlement panels.
There was no perfect laboratory waiting for us at the harbour. So, we built one.
We set up a small temporary workspace close to the experimental site and arranged everything we needed for the sampling. With the microscope, cameras, laptops, sampling equipment and the panels themselves, we quickly had our own little field laboratory ready to go.
Once everything was set up, the panels came out of the water. One by one, they were photographed, examined and assessed for the organisms that had settled on their surfaces. Some could be identified relatively easily, while others required a closer look under the microscope and a little more time.
The same basic procedure was repeated during the following sampling event, allowing us to compare how the panels had changed over time and which organisms had newly appeared or become more abundant.
Working directly at the field site also had its advantages. Instead of transporting the panels back and forth, we could examine and document them close to where the experiment was running and get an immediate impression of how the communities were developing.
Of course, the conditions were not always perfectly calm. Strong winds can make working at the harbour considerably more challenging, and this is where we really began to appreciate the Levante, the strong easterly wind that regularly affects the Cádiz area. By “appreciate”, we mean learning very quickly how much more complicated even a routine sampling day can become when the wind picks up. Even simple tasks require more coordination, especially when working with equipment and panels close to the water.
Nevertheless, the sampling days became one of the most interesting parts of the experiment so far. Every time we brought a panel out of the water, there was something new to discover.
The youngest member of the GAME team
There was also one very important member of the team who deserves a special mention.
During one of our most recent monitoring days, we had some unexpected assistance from a four-year-old.
While we were reading out the equipment, working on the frames and dealing with the usual collection of sampling tasks, our youngest helper decided that watching from the side was not enough. He wanted to participate.
So he did.
For a short time, we had officially found the youngest member of the GAME team. He may not have been able to explain the experimental design or tell us anything about sound pressure levels, but he was very enthusiastic about helping with the work. It was a small moment, but it was also a nice reminder that fieldwork is rarely as isolated as it can sound when described in a scientific paper. People around us had become part of the experience, whether they were helping with equipment, giving advice, asking questions or simply were curious about what two researchers are doing at the harbour with a collection of PVC pipes.
And occasionally, they became part of the team.
Life outside the frames
Of course, our time in Cádiz did not consist entirely of PVC, HydroMoths and sampling.
Living in Cádiz for several months also meant getting to know the city and the surrounding region outside the harbour. We spent a lot of our free time near the sea, whether that means going to the beach, playing sport or simply enjoying the city after a long day of fieldwork. With beaches, the old town a