A research team says it has debunked the long-held notion that appearances of deep-sea fish near the ocean’s surface are precursors of mega-earthquakes.

The researchers from Tokai University’s Institute of Oceanic Research and Development and the University of Shizuoka concluded that there is no correlation between the two events.

Numerous traditions nationwide state that when abyssal fish, including oarfish and slender ribbonfish, are caught in nets or wash up on a beach, a major earthquake is imminent.

According to one theory, such deep-sea fish rise to the surface to escape gases or electromagnetic waves emitting from the seabed right before an earthquake.

“We thought that if the folklore was true, it would be useful for disaster preparedness, but that was not the case,” said Yoshiaki Orihara, a specially appointed associate professor at the institute.

“In some regions, such traditions are believed. But we cannot say that they are useful for predicting earthquakes,” he added.

The research group checked 336 eyewitness accounts from November 1928 to March 2011 based on local newspapers, academic articles and other information. The sightings concerned about eight species, including oarfish and slender ribbonfish, believed to be warnings of an earthquake.

The researchers checked whether an earthquake of magnitude 6 or stronger had occurred in the 30 days after the sightings and with an epicenter within a 100-kilometer radius.

They found only one such quake, the Niigata Chuetsu-oki Earthquake of July 2007.

Details of the research project were published on June 18 in the online edition of U.S. science journal Geo Science World at (https://pubs.geoscienceworld.org/ssa/bssa/article-abstract/571628/is-japanese-folklore-concerning-deep-sea-fish).