In this undated photo provided by LittleFriendsPhoto.com via Six Flags Discovery Kingdom, Kai, a 17-year-old male California sea lion at Six Flags Discovery Kingdom in Valejo, Calif. peers into the lens of photographer Seth Casteel, known for his “Underwater Dogs” photo series. ... (Photo by Seth Casteel/AP Photo/LittleFriendsPhoto.com via Six Flags Discovery Kingdom)

A boy walks past boats docked at the entrance gate of the fishermen's village in the El Max area of the Mediterranean city of Alexandria September 12, 2014. El Max, where hundreds of boats dart through the canals, has been called the “Venice of Egypt” for its waterways and relaxed atmosphere. Its fishermen, however, worry about how they will make ends meet on meagre earnings they say are being reduced further by polluted waters that are making fishing more difficult. While the government has tried to fix the state's bloated finances by cutting subsidies and reining in spending, some argue the reforms hurt Egypt's most vulnerable who have long relied on a generous system of fuel and food subsidies to supplement low incomes. (Photo by Amr Abdallah Dalsh/Reuters)

“A Little Monkey on the Cliff”. “A cold front hit the Nagano prefecture. I saw a little monkey enduring the cold in Jigokudani Monkey Park. This little monkey is really cute”. (Photo by Hidetoshi Ogata/Smithsonian Photo Contest)

A farmer harvests broccoli in the town of al-Ansariyeh south of Sidon, Lebanon March 15, 2016. (Photo by Ali Hashisho/Reuters)

People walk during a polluted day in Shenyang, Liaoning province, March 31, 2016. (Photo by Reuters/Stringer)

A boy carries sugar cane through a farm on the outskirt of Zaria in Nigeria's northern state of Kaduna November 15, 2016. (Photo by Akintunde Akinleye/Reuters)

A combination picture shows Aleppo's Umayyad mosque, Syria, before it was damaged on March 12, 2009 (top) and after it was damaged (bottom) December 13, 2016. (Photo by Omar Sanadiki/Reuters)

5-year-old Rina Kumari rubs her eye while cracking stones on the banks of Mahananda river in Siliguri, northeast India, March 5, 2005. Over 400 million people in India live below the internationally agreed poverty line (living on less than US $1 per day). According to estimates, several hundred thousand children work as labourers and beg on the streets in India. (Photo by Desmond Boylan/Reuters)