having spent decades measuring water quality on the great barrier reef, doctor ridd claims the data usedcoral to agriculture is deeply flawed. so, for example, a drop of water that is offshore just here will be out in the pacific ocean in a couple of months. there's a massive amount of flushing of water from the pacific ocean that purifies the great barrier reef lagoon. there's as much water comes in from the pacific ocean in just eight hours as from all the rivers along the whole coast in the whole year. and this keeps the water quality of the great barrier reef really phenomenally good. with polluted river sediment from farming declared as a major threat to the great barrier reef, i have travelled with dr ridd to one of queensland's largest rivers. so this is the burdekin river, the biggest river on the coast, and it is dry at the moment but when it flows, it's actually one of the biggest rivers on earth. and some of the mud that comes out of this goes over the inshore reefs and a very tiny amount, just occasionally, reaches the great barrier reef itself. is this threatening the great

dr ridd also takes issue with the belief of an overwhelming number of scientists that the greatest threatsagree that there is a huge rush. the problems of climate change are going to hit the reef, if they are going to, in 100 years. there is billions of dollars being spent on the size of the reef and i think that a lot of the reef and i think that a lot of the threats to it are negligible, almost infinite is more, in fact. although most scientists reject dr ridd's assertions that the science is wrong, the australian government found his views credible, launching a senate enquiry into the quality of scientific data on the great barrier reef. with their research under a cloud of suspicion, reef scientists are appalled at the direction australia is moving. everyone is entitled to their own opinion but shouldn't the government be putting a hell of a lot of money into an enquiry and delaying any policy based on that? probably not. it is pretty disappointing, you know, there is a lot of evidence up another climate change is the biggest threat to the reef yet the policies that we are seen coming