Four swimmers were injured in a dolphin attack off Suishohama beach in central Japan, officials said Monday.
A 60-year-old man was also attacked with cuts on his hands after a dolphin broke his ribs on Sunday morning.
In a separate incident the same morning, a 40-year-old man was injured on his arm.
Two other attacks by the mammals on the same day brought the number of such attacks this year to six, local police said, as well as putting up warning signs advising people to avoid the dolphins.
Although it may surprise many people to hear that dolphins can be aggressive, hostile behavior toward swimmers is not unprecedented.
In 2013 two women were injured on the island by the same dolphins in ten days. One of them had a broken rib. A year later, a dolphin aggressively cornered five swimmers who had to be rescued.
According to the scientists, one plausible explanation for why the otherwise playful and supposedly “harmless” mammal might become aggressive is that wild bottlenose dolphins find swimming with humans “incredibly stressful,” because it changes their behavior patterns. can affect.
However, while their hostility towards humans may still surprise some, dolphins are known to be aggressive towards other sea creatures.
Recently, a video went viral that showed a bottlenose dolphin tossing a porpoise into the air off the coast of England.