Scientists set about to figure out what the mysterious substance was after beachgoers at Wells Beach found the ground was staining their feet and the sand.
Regular visitors reported seeing it on the beach first on Sunday 6 June. People, like Ed Smith, went back the next day and saw it again.
Mr Smith said to Portland Press-Herald, “I sat on the edge of my tub with blue Dawn (dishwashing soap) and a scrub pad, and I still couldn’t remove the stain from my feet.”
After further investigation, which included taking photos and samples, he showed his findings to the Department of Environmental Protection, concerned it might be poisonous.
Marine biologist Steve Dickson, who works at the Maine Geological Society, identified it to be millions of bug corpses.
A discovery he found remarkable.
“This is the first time I’ve seen or heard of this in my 35 years,” Dickson said. “Normally this time of year we get calls about too much seaweed (wrack) on the beach and the swarming flies that hang around the decaying seaweed. This wasn’t that.”
He mentioned there had been similar sightings at nearby York Beach, but had not heard of it being elsewhere
Jim Britt, a spokesman for the Maine Department of Agriculture, Conservation and Forestry, told the Boston Globe that it’s most likely a “harmless common kelp fly that feeds on decaying seaweed” and the black substance is “the pigment that occurs naturally from what they eat.”