A surfer rides a wave at the snowy beach of Unstad, in Lofoten Island, Arctic Circle, on March 9, 2016. Surfers from all over the world comes to Lofoten island to surf in extrem conditions. Ocean temperature is 6-7 °C, air temperature around 0°C in spite of a weather very unstable. (Photo by Olivier Morin/AFP Photo)

A river otter (lontra longicaudis) of 6-weeks-old looks in the mirror during a bath in the Animal Welfare Unit of the Zoo in Cali, Colombia, on October 22, 2019. The baby otter was found abandoned brought to the Cali Zoo for breeding, for its extensive experience in raising these species. According to the International Union for Conservation of Nature the river otter (lontra longicaudis) are in danger of extinction, because of mining, agriculture, pollution of rivers and housing construction in their habitat. (Photo by Luis Robayo/AFP Photo)

Tim Anderson final balanced rock stack in the Llano River. Tim Anderson, rock balancing “pro” from Pennsylvania, carefully worked to balance his stack on a dry spot in the Llano river Saturday March 12, 2016. He was an honored guest of the festival and enjoyed visiting Texas so he came for another year. The river was higher this year because of the rains so the balancers could not get to the better rock that were available last year. (Photo by Nell Carroll/American-Statesman)

A boat commutes across the Mekong river in Phnom Penh on August 8, 2014. The Mekong is the world's twelth longest river running from the Tibetan Plateau through China's Yunnan province, Myanmar, Laos, Thailand, Cambodia and Vietnam. (Photo by Tang Chhin Sothy/AFP Photo)

Policemen and residents run as waves from a tidal bore surge past a barrier on the banks of Qiantang River in Haining, Zhejiang province August 31, 2011. As Typhoon Nanmadol approaches eastern China, the tides and waves in Qiantang River recorded its highest level in 10 years, local media reported. (Photo by Reuters/China Daily)

The Rio Tinto river in Spain crosses an ancient mining site which makes the water turn a variety of bright colours. Copper, silver and gold are mined here, as well as iron, which turns the water red. An ochre mix is responsible for the yellow tint of the rest of the river. (Photo by Olivier Jarry-Lancombe/Solent News)