Residents living along the coast of Devon and Cornwall in the United Kingdom were left astonished as tens of thousands of giant jellyfish suddenly swarmed the region on Wednesday.
Wildlife Experts believe the surge in barrel fish numbers could have been caused by the increase in sea temperatures in the area, which would normally have chilly waters during this period.
It is now considered to be the largest population of jellyfish seen along the coast in 30 years.
People who were able to see the barrel jellyfish went on social media to share their stories and photographs of the sea creatures.
Keith Leeves, the captain of a sea life cruise named AK Wildlife Cruises, said seeing the giant jellyfish was "eerie" and "unnerving." He said there were thousands of creatures in the coast, and that he has never seen anything like it before.
Todd Palmer, a diver who was at Plymouth, Devon during the time, said the appearance of the giant jellyfish is usually a sign of a "good summer."
Conservationist Steve Trewhella, from Wareham, Dorset, was able to capture images of the sea creatures when he encountered hundreds of them at Chesil Cove.
"We never expected to stumble across more than we knew what to do with," Trewhella said.
"They were wonderful and such magnificent animals, and you just can't help but be impressed when you see a four foot long jellyfish by your side."
Trewhella added that the last time a similar phenomenon happened was during the 1980s.
While barrel jellyfish are not known to pose any direct threat to humans, experts still advise swimmers not to touch the sea creatures.
Matt Slater, Marine Awareness Officer for the Cornwall Wildlife Trust, explained that finding out what exactly caused the giant jellyfish to swarm the coast, but they think it might have something to do with the creatures' food source as warmer waters often produce more plankton.
Devon Wildlife Trust representative Steve Hussey, however, said the sudden increase in barrel fish numbers could be because there are fewer natural predators in region.
"The leatherback turtle is struggling at the moment, which means there are less of them to eat the jellyfish," Hussey said.
