A spectacular image of a rare “rainbow pool” phenomenon was captured in a swamp in Virginia.
The US Fish and Wildlife Service (USFWS) posted the photo– taken in the Great Dismal Swamp National Wildlife Refuge – to his Twitter account on Tuesday.
The Great Dismal Swamp spans southeastern Virginia and northeastern North Carolina and covers an area of about 750 square miles.
The image shows an unusual pool of water in the swamp that contains a kaleidoscope of beautiful colors ranging from blue and green to yellow and red. This phenomenon, aptly named “rainbow pool,” rarely occurs under certain conditions.
“How do you continue to work today after knowing that ‘rainbow pools’ exist,” the USFWS wrote in the Twitter post.
According to the agency, the colorful shine of the water, as can be seen in the picture, is not the result of pollution in this case.
Instead, the phenomenon is caused by natural oils released from decaying vegetation or by bacteria breaking down iron in the soil.
“These factors, coupled with several days of calm, undisturbed water and just the right angle of sunlight, will result in this rarely seen rainbow phenomenon in swamps and marshes,” the USFWS tweeted.
Rainbow pools occur in the Great Dismal Swamp during winter, the agency wrote in a subsequent tweet.
The Great Dismal Swamp National Wildlife Refuge is the largest intact remnant of a vast forested wetland. It once covered more than about 1,560 square miles in southeastern Virginia and northeastern North Carolina.
Established in 1974, the refuge is home to a wide variety of species, including more than 200 species of birds and about 100 species of butterflies and skippers.
You’ll also find turtles, white-tailed deer, bobcats and otters at the sanctuary, as well as one of the largest populations of black bear on the east coast.
“Swamps are amazing, especially the Great Dismal Swamp pictured here,” the USFWS wrote in a tweet. “They have a bad reputation, but swamps are home to so much biodiversity and wildlife.
“It really is a beautiful retreat,” the agency added.
In addition to being a home for wildlife, the swamp also served as a refuge for humans in the past. There is evidence that Native Americans hunted at this site thousands of years ago, with archaeologists uncovering ancient tools and weapons in the area. From the late 17th century to the time of the Civil War, refugees from slavery established settlements on the isolated swamp islands.
news week has reached out to the US Fish and Wildlife Service for comment.