An Iraqi Muslim woman walks past Christmas decorations for sale in the Shiite holy city of Najaf on December 17, 2015. (Photo by Haidar Hamdani/AFP Photo)

A leopard runs to at people as they run for cover in Katmandu, Nepal, on April 10, 2013. According to reports, 15 people were injured including three policemen and two officials from the Department of Forest. The leopard was later killed with the help of Nepalese policemen and local media. (Photo by Niranjan Shrestha/Associated Press)

ATTENTION: VISUAL COVERAGE OF SCENES OF INJURY AND DEATH

Women wearing face-kini masks lie on a beach to rest in Qingdao, Shandong province, China, June 3, 2015. A pale complexion is highly prized as delicate and feminine in China while dark skin suggests tanning caused by farming the fields or other lowly, outdoor work. (Photo by Reuters/Stringer)

The NASA Extreme Environment Mission Operations (NEEMO) 21 mission began on July 21 as an international crew of aquanauts splashed down to the undersea Aquarius Reef Base, located 62 feet below the surface of the Atlantic Ocean in the Florida Keys National Marine Sanctuary. The NEEMO 21 crew will perform research both inside and outside the habitat during a 16-day simulated space mission. During simulated spacewalks carried out underwater, they will evaluate tools and mission operation techniques that could be used in future space missions, including journeys to Mars. (Photo by Karl Shreeves/NASA)

Pedestrians walk past a truck with a giant Soviet Red Army hat seen on it, an installation created by Russian artist Vasily Slonov, during the annual “Winter Virage” motor sports festival dedicated to the Defender of the Fatherland Day on the embankment of the Yenisei River in Russia's Siberian city of Krasnoyarsk, February 23, 2015. (Photo by Ilya Naymushin/Reuters)

The 26th annual Visa Pour l’Image, the “Cannes Film Festival” of photojournalism kicks off, filling the French city of Perpignan with more than 3,000 of the world’s best photojournalists and photo editors, along with agencies from around the world. This year’s Visa Pour l’Image showcases 26 exhibitions around the city. Photo: Christians looting a Muslim shop in the “Combattants” district of Bangui. (Photo by Pierre Terdjman/Paris Match)

Todd Bretl specializes in underwater photography, and is able to capture striking photos of aquatic life big and small. His photos of sharks are particularly striking; though he rarely faces hostility from the animals, he tries not to spend too much time looking through his viewfinder and many shots are framed by educated guesses and impeccable timing. What follows are photographs taken over the past several years on trips to the Bahamas and Isla Guadalupe, an island off the coast of the Baja California peninsula in Mexico. (Photo by Todd Bretl)