(NaturalNews) There has been much speculation about some mysterious underwater "fairy rings" that have been spotted off the coast of Denmark.
Besides the fairy angle, some have suggested that perhaps they are the work of aliens. Others have had a more, say, realistic view: Maybe they were caused by heavy bombing during World War II.
None of those answers are correct, according to scientists and biologists.
Fairies have long been blamed, however...
In fact, the phenomena are rings of green eelgrass, and some of them cover a span of about 49 feet. Occasionally, they can be spotted in the clear Baltic waters off Denmark's coastal island of Mon. Tourists captured the rings in photos in 2008 and again in 2011, which sparked the kind of fabled storytelling usually reserved for crop circles or other alien feats, Mother Nature Network (MNN) reported. The site added:
[B]iologists Marianne Holmer from University of Southern Denmark and Jens Borum from University of Copenhagen assure that the circles have "nothing to do with either bomb craters or landing marks for aliens."
"Nor with fairies, who in the old days got the blame for similar phenomena on land, the fairy rings in lawns being a well-known example," Holmer and Borum said in a statement on Jan. 30.
The biologists have said they believe that the rings formed due to the radiating pattern in which the brilliant eelgrass tends to grow - and then dies when exposed to toxins. In the mud surrounding the eelgrass, scientists have detected elevated levels of sulfide, a substance that is poisonous to eelgrass and which tends to build up naturally in the kind of chalky seabed endemic to the region.
It can also build up unnaturally, when agricultural pollutants are introduced into an ecosystem.
Circles elsewhere are also explainable - sort of
"Most mud gets washed away from the barren, chalky seabed, but like trees trap soil on an exposed hillside, eelgrass plants trap the mud," the two biologists explained, according to MNN. "And therefore there will be a high concentration of sulfide-rich mud among the eelgrass plants."
Though it might resemble a type of seaweed, eelgrass is actually a flowering plant. And when it grows, it expands outward in all directions, creating circle-shaped colonies. While healthy adult eelgrass plants seem to be able to withstand the sulfide in their environment, the old plants at the heart of the colonies drop dead, the researchers said.
"The result is an exceptional circular shape, where only the rim of the circle survives - like fairy rings in a lawn," they added.
In lawns, so-called "fairy rings" are most often blamed on the outward growth of fungi. Both fairy rings and crop circles have confounded scientists for years. One noted example is located in the desert grasslands of Namibia, in southern Africa. There, researchers have offered a wide variety of explanations for the widespread field of circular patches. The explanations range from ants and termites to seeping gas and competition for resources.
As for crop circles, they are not some sort of special code or map or guide for alien beings. Most have been debunked as pranks and gags.