Paulo and Leo from Team Cabo Verde say bom dia to all out there and want to share experiences and news about their GAME project in the middle of the tropical Atlantic Ocean. They are based at the Ocean Science Centre Mindelo on the island of Sao Vicente.
Since the location of Mindelo in Cabo Verde is pretty new to the GAME programme – we are the second generation – we want to give you a short overview about the country, the island(s) and the institutions here that are involved in GAME.
Cabo Verde is a small country that consists of ten principal islands and some smaller ones. It was discovered in 1460 by the Portuguese explorer Don Afonso and was part of the Republic of Portugal till 5th July 1975, which is the Caboverdian independence day. The main spoken language is the crioulo of Cabo Verde, which has been derived from Portuguese. Like the dialects (some dialects cannot be understood by everybody) all islands are quite different in climate, landscape, people and culture.
São Vicente is one of the smaller islands in Cabo Verde, but has the second biggest city, Mindelo, with almost 80 thousand inhabitants, who make almost 16% of the whole Caboverdian population. Mindelo is not only the main city of the island, but is also very important for the entire country. This is because it has a natural port, Porto Grande, which is relevant for the marine economy that includes fisheries, trading of cargo and diesel, as well as some other commercial activities. Furthermore, the city benefited from several years of marine research at ISECMAR (Superior Institute of Engineering and Marine Science). The institute is now called FECM (Faculty of Engineering and Marine Science) and is part of the University of Cabo Verde. The culture of São Vicente is very different from those of the other islands, since it was influenced by the Portuguese and the British over the last centuries. The thinking and dressing of the people, celebrations, the gastronomy, arts and philosophy were always influenced by a mixture of Caboverdian and international traditions. The main cultural expression is the carnival of São Vicente that is considered the biggest African festival in that season.
The institutions that are involved here in the GAME programme are the University of Cabo Verde (UniCV) and the Ocean Science Centre Mindelo (OSCM). The first is a part of the University network of Cabo Verde with campi in Praia on the island of Santiago and in Mindelo on the island of Sao Vicente. From the university’s side the programme is supervised by the Faculty of Engineering and Maritime Sciences. The second institution, the OSCM, is a cooperation between the National Institute of Fisheries in Cabo Verde and GEOMAR in Kiel. The OSCM was founded in 2017 and it has its focus on oceanographic research. Furthermore, it offers space, in an around the building, to the GAME students, where they can run their experiments.
Coming back to the main part of the story:
After the GAME preparation course in Kiel in March was finished, Team Cabo Verde split up for a while. Paulo travelled back from Kiel to São Vicente quite fastly because of the cold weather in northern Germany and his sodad. The word is crioulo and describes a feeling of sadness and nostalgia. For further information about this sentiment, please listen to Cesaria Evora’s song called “sodad”. Leo spent some more days in Germany, before he jumped over the Atlantic to the Cabo Verdian island. Our staggered arrivals helped us a lot to get all the equipment together, since working and living on the islands is like a half-time job in logistics. Paulo checked all the possibilities for buying lab stuff, such as tubes and air pumps, and inspected the GAME-materials that were left from the project in 2018. Furthermore, he explored the lab capacities for our experiment at the OSCM. In the meanwhile, Leo started a shopping tour in Germany to get all the stuff that was needed for the experiments but is not available on São Vicente and packed the materials as extra luggage. In the end it was hard for him to close the bag, but the water filters, some meters of tube, pipette tips, cannula, tube adaptors, some chemicals, counting chambers and some other tools were packed safely.
Reunited in São Vicente in the middle of April and with a high amount of morabeza (crioulo: the Caboverdian way of hospitality), we started to transform an almost empty storage room into our experimental laboratory. This meant that we needed to build up enough shelves for our experiment, to install a sea water filtration system, to realize proper aeration for the particles resuspension and for the oxygenation of our experimental units, to install an automatic light system and to set-up an microalgae culture for feeding our mussels and for determining the mussels’ filtration rates.
Beside of these first constructions, we presented our project to the staff at the OSCM and to the class of our supervisor Corrine Almeida. We got some helpful advices and could use them during the planning and preparation of our experiments.
Parallel to the transformation of our experimental room, we started a search for the perfect plastic bottle to run our experiment in. All GAME teams of 2019 together decided to use PET bottles from which the bottom part was removed as experimental containers. In the lab set-up, the bottles should be placed upside down with an aeration tube coming from above that releases air bubbles near the down facing lids of the bottles. This should guarantee a proper oxygen supply for our animals and a proper resuspension of the negatively bouyant particles in the experimental containers. Since we only use particles with a density higher than sea water, they will sink down to the lid and to the walls of the bottle over time. With this fact in mind, we started our search for the perfect bottle with the vision of one that has perfectly smooth walls, so that settling particles will slide down. After searching in some mercearias (small local grocery stores), we found an almost perfect bottle with smooth walls and a volume of 2 L from a Caboverdian soda company (see picture 9). However, since we are working on one facette of the marine litter problem, we did not want to ask the company for new bottles, but wanted to keep our ideals alive and upcycle used ones. We focused our search on two different locations. First, because of the lack of a refund system in Cabo Verde, empty bottles are simply thrown into trash containers or directly into the environment after use. Because of this we started some trips to the city and the beaches to collect bottles from the trash containers and from the environment, which sometimes resulted almost in beach clean-ups. Collecting bottles on the day after the 1st of May at the beach of Baia das Gatas was a big success for us, but unfortunately not for the environment, since we could not carry all the trash from the beach… Additionally, we drafted a letter in which we asked people for collecting empty bottles for us and spread it all over Mindelo, while Paulo contacted many friends and spread the word also in the digital world. The search for bottles raised some attention about our project so that the local newspaper Inforpress published an article about it and we were invited to Radio Morabeza (a local Mindelense radio station) and ADECO (a consumer representing NGO). We gave some interviews and talked about the microplastic issue, our project and the GAME programme for students. And during a visit of the OSCM even the president of the Republic of Cabo Verde had a look at our experimental set-up and was very interested in the programme and the topic.
Beside of all these technical, organizational and logistic issues, we went out to the field from time to time to search for our test animals. Since we want to investigate the effects of microplastics on filter feeders and also want to compare these with the effects of natural seston particles, our goal was to find a filter feeding organism that is easy to keep and suited for measurements in a lab study. But remember, we are almost in the middle of the Atlantic Ocean next to the North Atlantic gyre. This means that the waters around Cabo Verde are quite oligotrophic and therefore not the perfect environment for filter feeders. After some discussions and planning with Evandro Lopes, who ran intensive research projects on the bivalves of the Caboverdian archipelago, we started our field trips to the western, northern and eastern coast of São Vicente to find a promising species: Brachidontes puniceus. In the beginning, our search was as hard as the search for bottles, since this species is very small (around 15-20 mm) and is very good in hiding in small holes in intertidal rocks. But finally we were successful in the lagoon of Baia das Gatas, which is in the north of the island, and near the fishing village of Calhau that is in the east of São Vicente.
So far so good: we got our test animals and collected over 200 bottles to convert them into experimental containers. But what about the feeding of our hungry mussels in the lab? In Kiel we planned to feed our mussels with living microalgae from a lab culture. Since there is not yet a micro algae culture running in the UniCV nor the OSCM, we started to establish our own cultivation system. First, we tried to use freshwater microalgae from the tank of Paulo’s turtles to feed the animals, since we could not find a marine microalga species. However, we had some luck and, with some logistic help from Germany, got some nutrients and started a population of unicellular diatoms, which we got from the newly built shrimp farm in Calhau. With the help of neon lights and good hopes we finally got our first batches of microalgae (Thalassiosira weissflogii) to feed the bivalves in the lab.
Now, after two months of preparations and organizations, we got bivalves, a working lab with an algae culture, a seawater filtration system, light and air supply, as well as enough PET bottles for our main experiment. Therefore, we started our pilot studies these days with 65 test individuals of Brachidontes puniceus. The pilot studies will provide us some information about the main experiment. We will, for instance, assess the body condition index of the bivalves and the amount of food they need. Furthermore, we can train the measurements of the response variables and estimate how much time the different procedures will take. Additionally, we will run a retrospective power analysis with the data of the pilot study to calculate how many replicates per treatment level are needed to gain enough test power for the main experiment.
During the last two months, we had a tough time with a lot of downs and highs and we felt often like what the Caboverdian morna music describes: sad and exhausted, but also positive about the future. Therefore, we are looking forward to the next weeks and are optimistic that our bivalves will do well in the lab. If everything is going smoothly, we will start with the real GAME in the beginning of July and let it run till September. That’s it so far from Team Cabo Verde on São Vicente. Stay tuned and have a look from time to time on the blog here, because the GAME experiments 2019 are now entering the crucial phase!
fca kul and boa noite!
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