Tourists watch from a boat at the reef "Barrier Reef" around San Pedro Island in Belize, on Oct. 22, 2013. The Belize Barrier Reef off the coast of Belize is part of the Mesoamerican Barrier Reef System, the world's second longest after Australia's Great Barrier Reef. Among the big diversity of species it has, there are Caribbean reef sharks, blacknose sharks (Carcharhinus acronotus) as well as fish of different colors that blend into the reef.(Xinhua/David de la Paz)