Selfie picture shows Swiss pioneer Bertrand Piccard during the last leg of the round the world trip with Solar Impulse 2 over the Arab peninsula July 25, 2016. (Photo by Jean Revillard/Bertrand Piccard/Reuters/SI2)

In this 1997 photo released by the International Fund for Animal Welfare, a seal hunter, right, threatens a cameraman with a knife during the filming of a seal hunt in the Gulf of St. Lawrence, Canada. “Huntwatch”, a documentary by the organization about the fight to end commercial seal hunts, premieres in September 2016 on Discovery. The producers say it includes grainy but powerful archive footage that had languished in the basement of the group’s headquarters on Cape Cod for nearly five decades. (Photo by Richard Sobol/IFAW via AP Photo)

A Somali fisherman carries a fish from his vessel on the shores of the Indian Ocean on Liido beach, in Mogadishu, Somalia November 4, 2016. (Photo by Feisal Omar/Reuters)

A staff interacts with a white lioness in a private zoo called “12 Months” in the town of Demydiv, Ukraine, January 13, 2016. (Photo by Gleb Garanich/Reuters)

An employee walks past a rotary dredge working at an open-cast iron ore mine of the Stoilensky mining and concentration plant (GOK), owned by the Novolipetsk (NLMK) steel mill, in the city of Stary Oskol in Belgorod region, Russia, August 4, 2015. (Photo by Maxim Shemetov/Reuters)

Egmont National Park in New Zealand with Mt. Taranaki at its center is seen in a Landsat 8 satellite image taken July 3, 2014 and released by NASA November 14, 2014. The image is from the book “Sanctuary: Exploring the World's Protected Areas from Space”, published by the Institute for Global Environmental Strategies with support from NASA, which was released this week. (Photo by Reuters/NASA/USGS)

Young female Ibex on the fork of Disteis (2,200 m), near the top of the Jof di Montasio (Friuli, Italy). (Photo by Stefano Zocca)

A worker walks through a salt pan on the eve of May Day or Labour Day on the outskirts of the southern Indian city of Chennai April 30, 2014. India is the third largest salt producing country in the world after China and U.S. with global annual production about 230 million tonnes, according to government data. (Photo by Reuters/Babu)