Mass Dolphin Die-Off on Coast "Omen of Anomaly" Sparks Japan's Anxiety

Mass Dolphin Die-Off Occurred 7 Days Before Tohoku Earthquake
However, Direct Link to Earthquake Is Difficult to Confirm

More than 30 dolphins were stranded on the coast of Japan, raising growing concerns that this might be a precursor to an 'earthquake.' Previously, dozens of dolphins were stranded before the Great East Japan Earthquake occurred.

On the 10th (local time), local media including Japan's NHK reported that 32 dolphins were stranded near the coast of Ichinomiya Town, Chiba Prefecture, Japan. According to the media, the dolphins were first discovered on the 3rd, and 15 of them were already dead.

The stranded dolphins were washed ashore over a stretch of about 500 meters along the coast. Dolphins that were still alive were rescued by residents and were able to return to the sea.

Dolphins swimming near the coast. [Image source=Yonhap News]

After this incident became known, anxiety spread within Japan about whether it was a precursor to a major earthquake. Previously, on March 4, 2011, 54 dolphins were stranded and died en masse off the coast of Kashima City. This was seven days before the Great East Japan Earthquake in the Pacific Ocean off the Tohoku region.

Regarding this, science journalist Nobumitsu Oomiya told NHK, "Dolphins are animals sensitive to waveforms. They emit ultrasound themselves to measure distance and direction," adding, "However, it is known that when rock movements become active on the seabed, currents and geomagnetism occur."

He continued, "The mass death in Chiba Prefecture is presumed to have been caused by currents generated from the rocks interfering with the dolphins, causing them to approach too close to the shore." In other words, active tectonic activity caused the dolphins to lose their sense of direction. Active tectonic activity also suggests the possibility of an earthquake occurring soon.

Hideki Shimamura, a specially appointed professor at Musashino Gakuin University, also emphasized to the media, "The area where the dolphins were stranded is where the southern Philippine Plate and the eastern Pacific Plate overlap, so earthquakes are originally frequent," and added, "We cannot deny the possibility of abnormalities occurring around the plates."

However, there are also rebuttals that caution against hastily linking the mass death of dolphins to the possibility of an earthquake. The Japanese media outlet Mainichi Shimbun cited the Japan Disaster Prediction Information Research Institute, reporting, "In the past 10 years, dolphins have stranded six times, mostly concentrated between February and May. It is also possible that they were washed ashore due to ocean currents."

Dolphins stranded on a beach on Tasmania Island last September. [Image source=Yonhap News]

In fact, even after the Tohoku Earthquake, there have been several instances of mass dolphin deaths, but no subsequent large-scale earthquakes followed. For example, in September last year, as many as 250 dolphins died en masse off the coast of New Zealand, but no earthquake occurred.

On April 10, 2015, about 150 dolphins were found dead in a mass stranding in Japan, causing public anxiety. However, no large-scale earthquake occurred at that time either.

The causes of dolphins losing their sense of direction are not limited to tectonic activity. According to research by the Japan National Research Institute of Far Seas Fisheries, dolphins may be disturbed by naturally occurring magnetic fields, but they may also have been stranded while fleeing from predators such as killer whales. Additionally, noise emitted by fishing vessels or sonar (SONAR - sound navigation and ranging) may have affected the dolphins.

This content was produced with the assistance of AI translation services.