A study by the Australian Institute of Marine Science (AIMS) has found that a combination of global warming, ocean acidity levels and decreasing carbonate contents in sea water has caused dramatic declines in coral growth rates across the reef in the past 18 years.

While farm run-off is commonly held responsible for declines in reef health, AIMS principal research scientist Dr Katharina Fabrucius told Rural Press this week that farm run-off could not be blamed for the decline.

This was because the decline in coral calcification witnessed during the research had happened in off-shore parts of the reef that could not be reached by farm runoff.

“Farm runoff does not extend to offshore reefs, so we don't believe it is a cause for this decline,” Dr Fabrucius said.

“Instead, the likely causes are interactive effects between warming oceans and ocean acidification, which are both caused by increasing concentrations of carbon dioxide in the atmosphere.”

Despite the clear findings that farming could not be blamed for this decline, Queensland’s minister for Natural Resources Craig Wallace said the study justified the Queensland Government’s plans to regulate farming practices adjacent to the reef.

“We know we'll have opposition out there from industry groups who don't want to see regulation put in place, but this sobering news today from AIMS shows that drastic action must be taken,” he told ABC Radio last Friday.

Mr Wallace’s response has mystified the Canegrowers organisation.

“It is like adding an apple to an orange and getting an elephant,” Canegrowers chief executive officer Ian Ballantyne said.

“There is no logical flow from one to the other as far as I can see.

“If the issue is about emissions management and about global warming, farming operations in Australia account for less than 2pc of all emissions, and within that intensive cropping like sugarcane is a fraction.