Thousands of tonnes of dead fish wash up on beach and nobody knows why

'I don’t think this much has washed up before.'

Thousands of tonnes of dead fish wash up on beach and nobody knows why

Thousands of tons of dead fish have washed up on a beach in northern Japan and nobody knows why.

The haul – mostly sardines and some mackerel – washed ashore in Hakodate on the northernmost main island of Hokkaido on Thursday morning.

It created a sliver blanket stretching half a mile along the coastline.

Locals said they have never seen anything like it. Officials posted a warning online urging people not to consume the fish after some bagged them up to eat or sell.

Sardines and mackerels are seen washed up on a beach in Hakodate, Hokkaido, northern Japan Thursday, Dec. 7, 2023. Thousands of tons of dead sardines have washed up on a beach in northern Japan for unknown reasons, officials said Friday. (Kyodo News via AP)
Sardines and mackerels are seen washed up on a beach in Hakodate, Hokkaido, northern Japan (Picture: AP)
Sardines and mackerels are seen washed up on a beach in Hakodate, Hokkaido, northern Japan Thursday, Dec. 7, 2023. Thousands of tons of dead sardines have washed up on a beach in northern Japan for unknown reasons, officials said Friday. (Kyodo News via AP)
Takashi Fujioka, a Hakodate Fisheries Research Institute researcher, said he has heard of similar phenomena before, but it was his first time to see it (Picture: AP)

Takashi Fujioka, a Hakodate Fisheries Research Institute researcher, said he has heard of similar phenomena before, but it was his first time to see it.

‘One possible cause is that the school of fish was chased by a larger fish, became exhausted, and was washed up by the waves,’ he suggested.

‘Another possible cause is that the school of fish entered cold waters during their migration and were then washed ashore. But details are uncertain.’

Follow Metro on WhatsApp to be the first to get all the latest news

Want to be the first to hear the world’s top stories? Metro.co.uk is now on WhatsApp sending vital updates and top trending stories straight to your phone.

Apps With More Than One Million Users
Follow us to receive the latest news updates from Metro (Picture: Getty Images)

Join the Metro WhatsApp community now for breaking news, juicy showbiz stories and must-watch videos from across our website.

Simply click on this link and select ‘Join Chat’. Don’t forget to turn on notifications so you’ll always be the first to hear the latest!

The decomposing fish could lower oxygen levels in the water and affect the marine environment, he said.

‘We don’t know for sure under what circumstances these fish were washed up, so I do not recommend eating them,’ Fujioka added.

Get in touch with our news team by emailing us at [email protected].

For more stories like this, check our news page.