The Mariana Trench is the deepest point in the oceanic world and it is home to at least a few bizarre species. During an exploration of the trench earlier this month, marine biologists discovered the deepest living fish at a depth of 26,716 feet below sea level.
This is a significant discovery for the scientific community. Scientists believe that it is a species of snailfish, but they admit that identifying the species is impossible without a physical sample. The fish was seen on video, but was not actually captured during the expedition to the Mariana Trench.
The 30-day voyage to the bottom of the western Pacific Ocean was carried out by a team of marine biologists led by Jeff Drazen and Patty Fryer. It was part of the ongoing Hadal Ecosystems Studies Program, also known as HADES, which is a collaborative project that is funded by the National Science Foundation. The goal of HADES is to learn more about the deep-ocean communities which have, until now, been merely subjects of speculation among members of the scientific community.
Researchers conducted the expedition aboard the research vessel Falkor. They did not go down to the Mariana Trench themselves. Instead, they sent remotely operated vehicles outfitted with video cameras to various depths ranging from 16,404 to 34,777 feet.
Drazen explained that their unique strategy was part of the reason behind their success. Most expeditions in the past have gone straight to the Challenger Deep, the deepest part of the Mariana Trench, and have concentrated their efforts on this particular section of the seafloor. Drazen describes this as attempting to study a mountain by focusing only on its summit.
By exploring multiple environments at various depths along the Mariana Trench, this most recent expedition was able to find quite a few bizarre species that are strangely at home in this cold and dark place. Multiple records for the deepest living fish were broken during the expedition. They had already discovered a new species of snailfish between 20,000 and 26,000 feet which held the record until they caught another new species on camera 700 feet further down.
Scientists describe the unknown species as having a white, translucent body. It propels itself with fins that look like wings and appear to be very fragile. Researchers drew the fish within camera range using bait, but they were unable to capture it.
The discoveries did not end with the deep-dwelling mystery fish. The team was able to obtain video footage of the rare supergiant amphipod, a large crustacean that is ten times bigger than typical amphipods. They were also able to bring back rock samples which will provide significant insight into the geology of this deep-ocean environment.
Scientists that have been fortunate enough to study the Mariana Trench and the bizarre species that are at home there consider themselves explorers of a new frontier. The hadal zone, which encompasses everything deeper than 20,000 feet, is definitely the least explored habitat on earth. Their findings will help answer questions concerning what organisms live there and how they have adapted to the extreme conditions.
By Dac Collins
Photo by Ocean Networks Canada – Flickr License