It is either a Ï bond or a lone pair on an atom of relatively high electron density in a molecule or ion, or a bond that must break during a reaction. An electron sink is an atom on a molecule or ion that can accept a new bond or lone pair of electrons.
Threats to the Reef. The Great Barrier Reef is one of the worldâs best managed reefs but, like other coral reefs, it faces threats such as: 1  Climate change. 2  Extreme weather.3  Declining water quality. 4  Coastal development. 5  Illegal fishing. 6  Crown-of-thorns starfish outbreaks. 7  Marine Debris.hreats to the Reef. The Great Barrier Reef is one of the worldâs best managed reefs but, like other coral reefs, it faces threats such as: 1  Climate change. 2  Extreme weather. 3  Declining water quality. 4  Coastal development. 5  Illegal fishing. 6  Crown-of-thorns starfish outbreaks.
The Great Barrier Reef is the world's largest coral reef system composed of over 2,900 individual reefs and 900 islands stretching for over 2,300 kilometres (1,400 mi) over an area of approximately 344,400 square kilometres (133,000 sq mi).The reef is located in the Coral Sea, off the coast of Queensland, Australia.The Great Barrier Reef can be seen from outer space and is the world's biggest single structure made by living organisms. This reef structure is composed of and built by billions of tiny organisms, known as coral polyps.he reef is located in the Coral Sea, off the coast of Queensland, Australia. The Great Barrier Reef can be seen from outer space and is the world's biggest single structure made by living organisms.