In this June 29, 2016 file photo, boats docked at Central Marine in Stuart, Fla., are surrounded by blue green algae. The 153-mile-long Indian River Lagoon has been plagued by harmful algae blooms. Water quality testing data analyzed by the AP showed the average phosphorous level – a byproduct of fertilizers and human waste that algae thrive on, rose nearly 75 percent between 2000 and 2016. (Photo by Greg Lovett/The Palm Beach Post via AP Photo)

Wakodahatchee wetlands, Delray Beach, Florida, US. Equipped with sinewy necks and spear-like bills, great blue herons can lunge with fearsome speed to strike their aquatic prey. Adults will also employ rapid stabbing motions as one aspect of their complex courtship displays; they’re seemingly dangerous moves, but fitting to the intensity of mating season. (Photo by Melissa Rowell/Audubon Photography Awards)

Student, Shoukria positions a stone for cutting at the Turquoise Mountain Gem cutting class on May 18, 2011, in Kabul, Afghanistan. The mineral resources of Afghanistan are relatively unexplored even with Afghanistan's mineral wealth of coal, copper, gold and iron ore, with precious and semiprecious stones, including high-quality emerald, lapis lazuli, red garnet and ruby. Given the country's remote and rugged terrain, on-going instability plus an inadequate infrastructure and transportation means that mining is still difficult. While many are trying to bring positive changes, Afghanistan's mining industry uses unregulated, primitive methods and outdated equipment. (Photo by Paula Bronstein/Getty Images)

After the success of their Superman series in 2013, the Canadian Mint debuted a new set of coins honouring the Man of Steel at this year's Fan Expo in Toronto. The collection is made up of three silver coins worth $10, $15 and $20, and a gold coin worth $100. Photo: Close-up of the $10 silver coin in the new Superman series from the Royal Canadian Mint. (Photo by The Canadian Press)

Giffords Circus’s show is touring the UK. Established in 2000, Giffords Circus is a small circus company that delivers circus / theatre fusion to the villages and market towns of the south west. It combines dance, comedy, horses and live music in a two-hour show, located on village greens in a small white tent surrounded by handmade burgundy and gold showman’s wagons. Photographer Tom Pilston goes behind the scenes to meet the performers. Here: The incredible, gravity-defying Konjowoch Troupe. (Photo by Tom Pilston/The Guardian)

Shimmering clearest blue and stretching as far as the eye can see, this is one of Iceland's famed crystal ice caves. The giant solid waves look frozen in time but they are slowly moving along as part of the Vatnajokull Glacier – which stretches across eight per cent of the island. The images were captured in February 2014 by British photographer Rob Lott, 49. Photo: A wide view of Rob Lott in the crystal ice cave in the Vatnajokull Glacier, Iceland. (Photo by Rob Lott/Barcroft Media)

They might look like something straight out of a horror film, but these extraordinary images have been created to show the special bond between cats and their owners. Photographer Sebastian Magnani, 28, from Brig, Switzerland, took pictures of dogs and their owners using the same position and camera settings before working his magic with editing software. The result is this startling set of images, which show the pooches with human clothes – one wearing a hoodie, another with a red coat, one with a shirt and cardigan, and another with a blue jacket. (Photos by Sebastian Magnani)