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.
More than a third of world's coral reef faces major bleaching event. A massive, global coral bleaching event is underway which could affect 38 per cent of the world's reefs by year's end, including the Great Barrier Reef, scientists have revealed.