An unusual amount of giant squid have been appearing off the coast of Japan, leading some fishermen to hail the sign as a bad omen. 

A record amount of the giant squid have been caught in nets or washed up on beaches since the start of the year, with some measuring up to 8 metres in length. 

Shigenori Goto, 44, is a fisherman who caught two of the squid off the Sado Islands, in Niigata prefecture.

"I had seen no giant squid before in my 15-year fishing career.  I fear it may be some kind of omen," he told the Japan times. 

The squid usually live at a depth of around 600 metres and can grow up to 14 metres in length.  They are rarely seen by humans under normal circumstances, with the usual sightings coming from dead squid that have floated to the surface. 

One reason suggested for the overpopulation of giant squid is the decreasing number of whales and sharks in Japanese waters due to fishermen hunting them.  A decline in a giant squids natural prey would logically lead to an increase in the population.   

Another explanation is that due to falling deep-sea temperatures, the squid have risen while looking for warmer water.

Before scientific advancement, giant squid were mistaken for sea monsters or mermen, with ever more fantastic explanations to explain the size and odd appearance of the creatures.