Oi tud drt? – To read this Kriol words here, to say “Hi, everything fine?”, means GAME is back in Cabo Verde.
This year, Melanie (Universidade Técnica do Atlântico, Cabo Verde) and Lotte (University of Freiburg, Germany) have the chance to experiment together as a binational team on a still largely unexplored topic: the influence of artificial light at night (ALAN) on macroalgae.
As the plane approaches the archipelago of volcanic origin with its collar mountains, in the middle of the ocean, it becomes clear that the small island of São Vicente (with an area only twice the size of Kiel) is a very special destination for our research. We are located in Mindelo, the capital of the island with around 75 000 inhabitants. São Vicente is one of ten islands of the archipelagic country, which is located just over 600 km off the coast of Senegal. The isolated location, surrounded by nothing but the sea and the sun, will give us a lot of pleasure and at the same time present us with many challenges. We would like to give you an insight into our daily (research) life.
As other GAME 2024 teams already presented, we are researching the influence of ALAN on macroalgae. The topic follows the research series on ALAN of the last GAME years, but for the very first time photoautotrophic organisms are considered. We raise the question whether macroalgae, as light-dependent organisms, change their properties in response to ALAN. To do this, we observe growth rates, photosynthesis rates and possible defense capacities against grazing in a laboratory experiment.
If in the evening you sit in a bar on the jetties of Mindelo, the research topic again becomes very real. Various species of macroalgae shine in the light of the harbour. A total of 330 species of macroalgae have been described for the archipelago. And even if this diversity is not yet available for our research, on an island state so far away from the mainland, the sea and all its biodiversity have a special importance. The Ocean Science Center Mindelo (OSCM) as a research hub for marine sciences between the European and African continent is therefore a perfect location for this international project. The OSCM currently houses our aquariums and with that is our current center of life.
The warm and open atmosphere of Mindelo makes it very easy to feel at home. And whether in a research context or in the remaining leisure time the island of São Vicente has much to offer for both, a marine biologist and a tourist. Every excursion to collect the experimental organisms is a small insight into the huge biodiversity of the tropical Atlantic. Whether corals, algae, starfish, crabs or creatures, that at least Lotte had no idea existed, the variety of colors and shapes is impressive.
And if you take a short trip to another beach in Sao Pedro on the weekend, you will find yourself in the breathtaking experience of swimming with turtles (Chelonia mydas).
But for all the beauty of the picturesque island life, the availability of everything is sometimes limited. So the answer to the question “where can we get that?” is often a laugh. This always gives you the chance to show creativity and to practice patience. Especially in the beginning, a short errand can turn into hours of walking through the small stores of Mindelo. And without a local person and fluent Kriol it seems an impossible challenge to simply buy things, find the way to the next shop or get technical help. But with a certain amount of acceptance and perseverance, we managed to build a suitable set-up and get (almost) everything we needed.
We are currently preparing our second experiment. In which Echinometra lucunter will again be the grazer and the choice of algae species is still in process. The sea urchin species Echinometra lucunter is found in the western Atlantic Ocean and the Caribbean Sea. It can grow to a diameter of about 8 centimetres. The color varies from black to deep brownish-red.
But even if the project sometimes gives us many causes for concern, jumping into the waves on the Atlantic in the evening can always clear your mind and refresh you for the next day.
Cheers,
Melanie & Lotte
Ocean Acidification
Dr Heidarzadeh’s TV interview with SkyNews on the massive M7.7 Panama earthquake on 9 October 2026
Dr Heidarzadeh’s TV interview with SkyNews on the massive M7.7 Panama earthquake on 9 October 2026. Click here for the full story.
Dr Heidarzadeh’s TV interview with SkyNews on the massive M7.7 Panama earthquake on 9 October 2026
Our ocean is an incredibly vast and mysterious place. And there is no place where that is more evident than the deepest ocean area in the world: the legendary Mariana Trench. Located east of the Philippines, the Mariana Trench lies in the Mariana Archipelago in the western portion of the North Pacific. The greater area of the Mariana Trench Marine National Monument is made up of more than 95,000 square miles of ocean. Beneath these waters lie incredibly complex aggregations of submerged islands and volcanoes … and of course, an astoundingly massive trench.
Dive in with us to have your biggest questions answered about the famed Mariana Trench.
How deep is the Mariana Trench?
The deepest part of the Mariana Trench, known as Challenger Deep, is almost 36,000 feet below the ocean’s surface. For context, Mount Everest is about 29,000 feet above sea level, so the Mariana Trench is about 7,000 feet deeper than Mount Everest is tall. For one more comparison, the RMS Titanic lies at a depth of about 12,500 feet below sea level. The Challenger Deep is in waters nearly three times deeper than this ship’s final resting place.
Due to its enormous size, the Mariana Trench has at times been affectionately nicknamed the Grand Canyon of the ocean. This is certainly a picturesque image, but don’t let the mammoth size of this U.S. national terrestrial park fool you into thinking the Mariana Trench matches its size. The trench’s footprint is estimated to be 120 times larger than the Grand Canyon’s, and to reach the bottom of Challenger Deep, you’d need to descend through almost six Grand Canyons stacked on top of each other before you’d reach the seafloor.
Oh … and did we mention it’s five times wider than it is deep? It’s about 43 miles wide!
What is Challenger Deep, and how long would it take to reach it?
Challenger Deep is the deepest point of the Mariana Trench. Fewer than 30 people have ever journeyed to this area. The trek below the surface is long, dark and time-consuming, and it’s not an expedition considered lightly by scientists and explorers.
The first people to descend into the depths of this area in 1960 were oceanographers Jacques Piccard and Don Walsh, and it took them close to five hours to reach Challenger Deep. Since then, more advanced submersibles have been created, but it still takes two to four hours for modern vessels to reach such depths. For example, explorer and filmmaker James Cameron reached the seafloor in a little more than 2.5 hours in the first documented solo submarine dive to the area, and it took oceanographer Dr. Dawn Wright about four hours in 2022. It is crucial that these submersibles descend slowly and steadily beneath the surface, as the immense water pressure compounds with every mile a submersible descends. Speaking of pressure …
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What is the water pressure at the bottom of the Mariana Trench?
If you thought the depth of the Mariana Trench was its only jaw-dropping feature, think again. Water pressure is one of the most important factors affecting deep-sea life. In the ocean, pressure increases by one atmosphere for every 33 feet (10 meters) of depth. One atmosphere (a unit of measurement for pressure equivalent to average air pressure at sea level) is equal to about 14.7 pounds per square inch (PSI), which is the approximate standard atmospheric pressure at sea level. If you were to convert atmospheric pressure into weight, one atmosphere is about the weight of a bowling ball. Stay with me, friends.
If a vessel were to dive 2,000 feet below the surface, the pressure would equal that of 60 bowling balls stacked atop every square inch of that submersible. But 60 bowling balls is simply nothing compared to the pressure in the Mariana Trench. The atmospheric pressure at the depths of Challenger Deep is equal to about 16,000 PSI. That pressure is about the same as the weight of an entire full-grown elephant on every square inch of a submersible!
Need a more extreme comparison? If a human were to be placed at the bottom of the Mariana Trench, the pressure would be equal to that of 50 jumbo jets piled on top of a person!
Do any animals live in the Mariana Trench?
The depths of the Mariana Trench come with immense pressure and extreme darkness, but somehow, life finds a way to survive. Organisms that live at an extreme depth, like that of Challenger Deep, have to be highly adapted to low temperatures (typically just above freezing), high pressure and virtually no light at all.
Species found in the depths of the Mariana Trench might look vastly different from animals from other ocean depths because their anatomy has been refined to thrive in harsh conditions. At such great depths, these animals typically depend on chemosynthesis (using nutrient-rich waters being pumped out of hydrothermal vents) or descending detritus (dead matter that has fallen from higher parts of the ocean) for food, such as whale falls. Just a handful of these animals include species of octopuses and squids, sea cucumbers, amphipods, sea jellies, shrimp, sea worms and some wild-looking fish!
In 2025, more than 7,000 new species were discovered in the Mariana Trench, including the hadal snailfish (Pseudoliparis swirei). This is the deepest-dwelling fish currently known to science. Now, the fish has been dubbed “the Mariana snailfish.”
How was the Mariana Trench formed?
The process by which the Mariana Trench was created is a geologically fascinating one known as subduction. On the Earth’s surface, there are thin plates that cover the planet’s mantle, which is made of molten rock. If two of these plates collide, one pushes down into the Earth’s mantle while the other is pushed over the bottom plate. When this happens, a trench is formed from the drag of the bottom plate. This process can sometimes create incredibly strong earthquakes. The plates that forged the Mariana Trench’s creation are estimated to be up to approximately 180 million years old.
This trench was unknown to scientists until 1875. It was then that a team of explorers on the HMS Challenger measured the depth of the sea by simply lowering a weighted rope into the water. They were baffled when they measured that first portion of the seafloor to be five miles below the surface. And so was born the origin of some of the most daring deep-sea explorations known to mankind to date.
Is the Mariana Trench protected?
The Mariana Trench is in waters off Guam and the Mariana Islands. The region is protected from some human activities under its status as a marine monument. The creation of the Mariana Trench Marine National Monument signified that international, national and local leaders all recognize the importance of protecting this area.
However, just because the region is protected does not mean it’s not vulnerable to modern threats to ocean health. Plastic bags have been spotted in the Mariana Trench during several expeditions, highlighting the far-reaching impact of the marine debris problem. No corner of our ocean is safe from the ever-present threat of plastic pollution. The reality of a changing climate makes the future well-being of wondrous places like the Mariana Trench uncertain. What’s more: More than 70% of the global ocean has yet to be mapped. And what we don’t yet know about, we cannot wisely work to protect.
It’s up to us to work together to defend our ocean, from the sandy shores of our favorite beaches to the deepest, darkest parts of the sea. Together, we can work to protect our ocean as a whole, which ultimately helps protect treasured places like Challenger Deep.
Find out how you can join Ocean Conservancy’s wave of momentum to secure a healthy ocean and a thriving planet, forever and for everyone!
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