Hydrothermal Vents Discovered in Chamorro Seamount as NOAA Explores Marianas Trench

Scientists were surprised to discover hydrothermal vents at a place deep under the sea that was initially thought to be a dead zone. Their delight can be heard in a video shared by the National Oceanic and Atmospheric Administration (NOAA). 

"Hydrothermal vents are most commonly found near areas that are volcanically or tectonically active," reads the video's caption. "So when scientists using NOAA Ship Okeanos Explorer set out to explore Chamorro Seamount, which had no known historic eruptions, they weren't expecting to find vent communities ...but they did. Seen at a depth of ~980 meters (3,215 feet), the hydrothermal vents on the outer southeast slope of the seamount's summit crater were indeed an unexpected, and exciting, discovery." 

The chimneys that the scientists saw were rather small, measuring only around 1 to 2 meters in height, with the temperature of one vent measured at 31.14 degrees Celcius. The hot fluids that come out of these vents are important for life in such communities because the fluids contain hydrogen sulfide and other minerals that provide bacteria with sustenance. 

"Chemosynthetic bacteria are at the heart of deep-sea communities, sustaining life in absolute darkness, where sunlight does not penetrate," the description reads. 

The researchers saw a variety of marine life that normally inhabit vents, including Alvinoconcha snails and alvinocaridid shrimp, as well as amphipods, rare blind lobsters, cutthroat eels and rattails. There were also a variety of fish and two species of unidentified demosponges, but the most dominant is the stylasterid corals. 

The dive was the seventh in the third leg of NOAA's 69-day expedition of the Marianas Trench, located in the western part of the Pacific Ocean. The first leg took place from April 20 to May 1, and the second leg lasted from May 20 to June 11.

This third one started on June 17, and the focus of the "telepresence-enabled ROV/CTD/mapping cruise" is on the northern part of the Marianas Trench Marine National Monument (MTMNM) and the Commonwealth of the Northern Mariana Islands (CNMI). The expedition can be viewed live online until it concludes on July 10.