facebook
twitter
rss
account
search
search
 

Scientists offer explanation of mysterious ocean circles off Denmark

Jan. 30, 2014 at 7:08 PM   |   Comments

COPENHAGEN, Denmark, Jan. 30 (UPI) -- Danish scientists say they've solved the puzzle of mysterious ocean circles in the Baltic Ocean, saying it's down to sea grass and toxic mud.

Since the first images of the mysterious ocean circles off the Baltic coast of Denmark were taken in 2008, people have tried to find an explanation, researchers at the University of Southern Denmark and the University of Copenhagen said.

"It has nothing to do with either bomb craters or landing marks for aliens," biologists Marianne Holmer and Jens Borrum said. "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."

The circles consisted of eelgrass plants growing on the bottom of the shallow water, they said, but the puzzle was why they were growing in circles, since eelgrass usually grows as continuous meadows on the seabed.

"We have studied the mud that accumulates among the eelgrass plants and we can see that the mud contains a substance that is toxic to eelgrass," Holmer and Borum said.

The poison is sulfide, a substance that accumulates in the seabed, they said.

Sulfide is toxic enough to weaken both old and new eelgrass plants but not toxic enough to harm strong, adult plants, and since eelgrass spreads radially from the inside out the oldest and weakest plants are located in the center of the growth circle, they said.

"The result is an exceptional circular shape, where only the rim of the circle survives -- like fairy rings in a lawn," the researchers said.

© 2014 United Press International, Inc. All Rights Reserved. Any reproduction, republication, redistribution and/or modification of any UPI content is expressly prohibited without UPI's prior written consent.
Most Popular
1
SpaceX breaks ground on commercial launch site in Texas SpaceX breaks ground on commercial launch site in Texas
2
Antarctic fish have antifreeze in their veins Antarctic fish have antifreeze in their veins
3
Android phones to join iPhone in saying no to the police Android phones to join iPhone in saying no to the police
4
Watch India insert its Mars orbiter live online Watch India insert its Mars orbiter live online
5
Populist science: Pluto is a planet Populist science: Pluto is a planet
Trending News
Video
x
Feedback