In late October, a group of researchers from Senckenberg (including the SOSA project) and other research institutes embarked on a deep-sea expedition!
The international team of 28 scientists was aboard the research vessel “Meteor” for six weeks, sailing through the Atlantic between North Africa and South America to get to the bottom of some unsolved mysteries of the deep sea!
These mysteries take place 6000 meters deep, in a part of the Atlantic called the Vema Fracture Zone. In this region, high-level sonar mapping of the seafloor revealed that the bottom of the ocean might not be as uniform as once thought. Rather than a typical muddy seafloor landscape, this area showed unique rocky formations that prompted the need for further investigation. Specifically, the researchers onboard were interested in how these unique seafloor conditions – jagged rocky reefs and turbulent currents – affect the diversity of the species living there. As this is a new and previously unexplored ecosystem, they also expected to find many species that are new to science!
To investigate the rocky landscape – and the animals that live there – the team onboard used a device called an Ocean Floor Observation System (OFOS) that is equipped with multiple high-resolution cameras specially designed to withstand the unique pressures of being submerged in the deep-sea. This system, after sinking nearly 6,000 meters deep, captured videos of the rocky formations and the life on the seafloor.
These visual systems help scientists explore and see areas that no human has ever been before! What they found was an environment often teeming with life, from dumbo octopuses to tiny hooded shrimp. The OFOS captured crustaceans crawling along the seafloor, anemones perched atop rocky formations, sea stars half-buried in sediment, sea cucumbers crawling – and swimming! – around the area, and many, many more traces of incredible deep-sea life. Click on the photos to the left to see what types of animals live in this unique deep-sea rocky habitat!
To further study, and likely describe some of these unique animals, the scientists had to collect a few to bring onboard and bring back to the Discovery lab in Frankfurt. To collect the deep-sea specimens, the team used different devices, including a box corer and multi-corer that collect species living in the sediment and an Epibenthos sledge that collects specimens from the top layer of sediment and the water column just above.
The box corer is a device that sort-of acts as a giant cookie cutter for the seafloor. It cuts out 50×50 cm samples from the seafloor, that are then brought up to the surface where the sediment is sieved to remove rocks and find tiny invertebrates. The researchers focus on the top 10 cm of sediment because that is where 90% of the bottom-dwelling animals live. The multi-corer is similar in its cookie-cutter concept, but it uses several long tubes to simultaneously slice through the seabed and produce cylinder-shaped samples of sediment which can then be investigated and even x-rayed to look for life in the different layers of seafloor.
The Epibenthos sledge takes a much different approach to collecting samples. This device is similar to a sled with two very fine mesh nets attached. The sled gets towed behind the ship, gliding across the seafloor. The bottom net collects samples from the sediment and the top net collects samples from the water column just above the seafloor. The mostly microscopic animals are funneled to a collection box where they are brought to the surface and kept on ice to preserve their DNA and RNA to ensure molecular research can be done when they arrive back at the lab.
Most of the animals collected from the devices are very small – often less than 15 mm in size. But even though they are small in size, they are incredibly important to helping us understand the diversity of the deep ocean. While the expedition can be some of the most exciting work happening in taxonomy, arguably the most critical work is what happens AFTER the expedition ends.
After the expedition, researchers will sort through the specimens in the lab and get a better idea of the diverse life inhabiting this unique rocky landscape. For some of the unknown marine invertebrates, SOSA scientists will work to describe and name these species so that they can be further studied, and if needed, protected. It is exciting to find animals that are new to science, that no one has ever seen before, but it is the work to describe and name these species that really allows for us to understand and take action to preserve this incredible marine biodiversity. So, while deep-sea expeditions are pretty incredible, the taxonomic work that happens after the expedition is even more important!
Check out some of the amazing specimens below and explore the onboard updates from the head of SOSA’s Engagement Unit, Dr. Alica Torkov, on our Instagram: https://www.instagram.com/oceanspecies.
