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 250,000 crown-of-thorns starfish have been removed from the Great Barrier Reef off Queensland in the past two years, Federal Environment Minister Greg Hunt says. The pest is considered to be one of the biggest threats to the reef and has traditionally been hard to destroy.