Our knowledge of outer space almost exceeds what we know of the Earth's deep seas, and the more we explore, how much we don't know becomes more apparent.
In a new study from the University of Hawaiʻi at Mānoa, researchers state that they were able to coax out the largest collection of fish ever recorded in the deep sea: a massive swarm of 115 cutthroat eels.
The researchers accomplished this feat by only using a relatively small package of bait to attract cutthroat eels into the light from the abyssal deep-sea region found between 9,800 and 19,600 feet (3,000 to 6,000 m) beneath the ocean surface, per New Atlas.
The video shows the eels being lured by a small bait package that contains 2 pounds (1 kilogram) of mackerel. The animals feast on the food and escape the scene shortly after.
Biological oceanographer Astrid Leitner, who worked on the research, said in a statement, "Our observations truly surprised us. We had never seen reports of such high numbers of fishes in the sparsely-populated, food-limited deep-sea."
Due to the extremely scarce amounts of food found in the depths, it's highly unusual for the same species to be found in large numbers.
Deep sea mining industry might damage the biodiversity
Scientists know very little about this species, and fewer than 10 specimens have been collected worldwide, per IFLScience. Since the Clarion Clipperton Zone (CCZ) they were found in is currently being examined by the deepsea mining industry for the extraction of minerals and metals, marine biologists worry about the biodiversity in the area, which remains vastly unknown.
Mining is reportedly disruptive to sea-bed ecosystems, and the damage reversal can be incredibly slow, Science Alert reports. Leitner added, "If this phenomenon is not just isolated to those two seamounts in the CCZ, the implications on deep-sea ecology could be widespread. Our findings highlight how much there is still left to discover in the deep sea, and how much we all might lose if we do not manage mining appropriately."