Stunning images taken by Sean Lenz, 19, and Kristoffer Abligaard, 20, show picturesque waterfalls transformed into vibrant rainbows of colour. The awe-inspiring images were created by clever use of long exposure photography and glow sticks floating through water. Photo: Picturesque waterfalls transformed into rainbows of colour. (Photo by Sean Lenz/Kristoffer Abildgaard)

Bangladeshi fisherman feed their otters as they catch fish in Narail some 208 kms from Dhaka on March 11, 2014. The fishermen are using a rare technique that relies on coordination between man and trained otters, a centuries-old fishing partnership that has already long died out in other parts of Asia. (Photo by Munir Uz Zaman/AFP Photo)

A visitor takes a picture of goldfish at the Art Aquarium exhibition in Tokyo Friday, August 12, 2016. The exhibition, featuring around 8,000 goldfish in tanks themed on Japan's Edo Period. (Photo by Koji Sasahara/AP Photo)

Sugar gliders, Candy and Popcorn, enjoy their favourite food, Nectar, at Wild Life Sydney Zoo on February 14, 2017 in Sydney, Australia. The treat made up of honey, high protein baby cereal and egg yolks is the human equivalent to chocolate to the Sugar Gliders. St. Valentine's Day or the Feast of Saint Valentine began as a celebration of the early Christian Saint Valentinus. From the 18th Century onwards it has steadily transformed into a celebration of romantic love and sentiment in many countries around the world. (Photo by James D. Morgan/Getty Images)

A man is silhouetted in front of the Allianz-Arena as he walks his dogs at sunrise in Munich, southern Germany, Friday, April 10, 2015. (Photo by Peter Kneffel/AP Photo/DPA)

People wearing costumes walk during Halloween in Sierra Madre, California, U.S., October 31, 2017. (Photo by Mario Anzuoni/Reuters)

Lightning strikes above Perch Rock Lighthouse in Merseyside, North West England on August 10, 2020. (Photo by Bav Media/The Sun)

NASA's new moon rocket lifts off from the Kennedy Space Center in Cape Canaveral, Wednesday morning, November 16, 2022, as seen from Harbor town Marina on Merritt Island, Fla. The moon is visible in the sky. (Photo by Malcolm Denemark/Florida Today via AP Photo)