Aquarium visitors attend a dinner party in an underwater tunnel in Tianjin, China on September 15, 2016. Tianjin Haichang Polar Ocean World opened in the city of Tianjin, southeast of Beijing, in 2010. It gives visitors a chance to see more than 150 large animals from the Arctic and Antarctic regions, including polar bears. (Photo by Feature China/Barcroft Images)

Activists attend a parade to demand rights of gender equality to LGBT community members in Santiago, Chile, November 25, 2017. (Photo by Ivan Alvarado/Reuters)

David Goffin of Belgium meets a koala during a promotional event for the Australian Open tennis tournament at Melbourne Park on January 17, 2018. (Photo by Fiona Hamilton/Reuters/Tennis Australia)

Activists participate in the Walk of Lesbian and Bisexual Women in Paulista Avenue, SP. The act was organized by the LGBT (lesbian, gay, bisexual and transgender) in São Paulo, Brazil, on June 2, 2018. (Photo by Cris Faga/NurPhoto via Getty Images)

An elephant sprays tourists with water in celebration of the Songkran Water Festival in Ayutthaya province, north of Bangkok, Thailand April 11, 2017. Trained elephants sprayed motorists and passers-by with water in Thailand's old capital city of Ayutthaya on Tuesday to welcome in the Buddhist New Year, known as “Songkran”. (Photo by Chaiwat Subprasom/Reuters)

The fourth annual BigPicture Natural World Photography Competition aims to celebrate the diversity of life on Earth, and encourages people to protect and conserve it. Here: “The Salmon Catchers”. Terrestrial Wildlife. To capture this view of a mother grizzly bear and her cub, photographer Peter Mather set up a camera trap on a log that he knew the bears tended to traverse while fishing for salmon, in the Yukon River watershed in Canada. (Photo by Peter Mather/BigPicture Natural World Photography Competition 2017)

A woman surveys the damage after the earthquake on March 17, 2011 in Kensennuma, Japan. (Photo by Chris McGrath/Getty Images)

A lighting bolt flashes in the sky as U.S. Army M1A1 Abram tanks roll through the desert December 9, 2002 near the Iraqi border in Kuwait. (Photo by Joe Raedle/Getty Images)