The Great (Shrinking) Barrier Reef?

Here's a scary thought.

The Great Barrier Reef is shrinking and there could be nothing left but a slimy underwater forest of algae within 90 years, a scientist has warned.

The Australian Institute of Marine Science and James Cook University's Dr Eric Wolanski has created a frightening picture of what the reef is likely to look like by the year 2100.

His study was based on past and future averaged coral cover on the Great Barrier Reef between Lizard Island and Bowen.

Using physics and historic coral reef cover data, Dr Wolanski suggests the reef has been steadily shrinking since European settlement of Australia.

The main cause of this has been mud and chemicals washed onto the reef from farms, which has choked the coral, cutting it off from sunlight.

It has been shrinking at a rate of about 20 per cent every 100 years.

Dr Wolanski said the reef would continue to die off unless better land management controls were brought in.