Unravelling the Mysteries of the Deep Sea

We live on the blue planet, so-called because almost three-quarters of the Earth’s surface is covered by water. Yet, most of our oceans, particularly their deepest regions, remain unexplored. “The deep ocean is the biggest wilderness on Earth,” says Dr Furu Mienis, senior scientist at the Royal Netherlands Institute for Sea Research (NIOZ). Her research focuses on uncovering its mysteries and encompasses sedimentology, ecology, and physical oceanography. She’s fascinated by the fact that organisms like corals and sponges can thrive in the cold, dark, and hostile environment of the deep sea where there’s a very limited food supply.

Furu and her colleagues at NIOZ are part of a Dutch consortium of scientists who were recently awarded a prestigious multi-million euro grant for the North Sea-Atlantic Exchange (NoSE) project. The aim is to investigate the exchange of carbon and other nutrients between the North Sea, a coastal sea, and the Atlantic Ocean to determine what effect it has on the global climate. She explains, “Coastal seas take up a lot of carbon dioxide from the atmosphere through physical, biological and sedimentological processes. But where all this carbon goes and how it affects the global ocean is not very well studied. In this project, we propose to study a deep part of the North Sea, the Norwegian Trench, which is the main export route for water flowing from the North Sea into the Atlantic.” They’re going to look at how much carbon and other nutrients come into the trench, what happens inside the trench, and what then flows out into the Atlantic Ocean.

NIOZ is the Dutch national hub for marine research and offers everything a researcher in this field could need, including access to a fleet of research vessels. As part of this project, Furu and her team will go on research cruises on board the open-ocean research vessel, Pelagia. They plan to carry out experiments at sea and even develop some new equipment to collect different types of measurements.  “We’re lucky here at NIOZ – we have a huge workshop that can more or less develop anything that we want for deep-sea work. I think it's a real advantage to work at NIOZ because almost everything is possible as long as there's funding,” she says.

The engineering team in the NIOZ workshop will develop different measuring and sampling instruments to equip a lander platform. The lander, a type of carrier system – a bit like a Mars lander – will then be deployed at the sea floor, where it will remain for up to a year collecting long-term data. Carrying out experiments in situ will give more accurate results than harvesting samples and analysing them back in the lab. This is because it’s very difficult to mimic the exact conditions found on the sea floor in the lab, especially the pressure, which is way higher than that experienced on land. Furu and her team will also search for clues in sediment cores to discover what changes have occurred to the inflow and outflow of the trench over time. This sediment from rivers, glaciers and remains of marine organisms has accumulated over thousands of years in the Norwegian Trench and changes in its composition will help build a picture of what’s happened in the past, and with the help of computer modelling, what could happen to our climate in the future.

Furu loves the outdoor life and enjoys living close to the sea on Texel, the island, two hours north of Amsterdam, where NIOZ is located. She did her PhD and postdoc at NIOZ, and after a brief spell away, returned, drawn by its encouraging atmosphere and openness to new ideas. She feels that it’s a welcoming environment and praises its efforts to promote diversity and inclusion within the organisation. NIOZ’s focus on multidisciplinary research is also very important for her work. “My research overlaps with a lot of different disciplines, so for me, it's the ultimate place to be,” she says. “I can easily get information from experts in the institute. For example, if I need a biologist, they're just around the corner, which is really nice and also makes it the kind of open environment where everybody works together and can discuss things.”