the Great Blue Hole, Belize

With its geological peculiarity - 300 m diameter and 124 m depth - and its perfect circular form, the Great Blue Hole is nothing but an abyss. These abysses appear after the fall of the roof of subterranean caves, destroyed by the water on the limestone rocks. It is an extraordinary fact that after the last glacial period the sea level has risen hundreds of meters. This spot on the ocean, beloved by divers, is part of a big set called Mesoamerican Coral Reef, which spreads over almost a thousand kilometres, from the tip of Yucatan in Mexico to the north-eastern coast of Honduras, bordering the coast of Belize and Guatemala. Together with the Great Coral Reef and the New Caledonia, it is one of the largest in the world, the largest in the northern hemisphere and the largest in the Atlantic Ocean. This ecosystem hosts over 65 hard coral species and 500 fish species. It suffers the impact of global warming, damages caused by fishing and tourism, as well as urban and agricultural pollution. In Belize the development of shrimp farming is particularly worrying. In Guatemala the oil terminal of Santo Tomas del Castillo, through which over one million tons of petroleum goes through, is a threat in case of an accident or oil spill. The coral formations are precious to our planet because in spite of covering less than 2% of its surface they host over a quarter of all known marine species.