The Turnbull government is promising to spend $500 million to help restore and protect the Great Barrier Reef.

Federal Environment Minister Josh Frydenberg and Foreign Minister Julie Bishop said the pledge - announced on Sunday ahead of the May budget - was a game-changer and would help secure the reef's future.

"This is the single largest investment in restoration and management in Australia's history," he told ABC News.

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Some of the funding will be funnelled directly to farmers to enable them to modify their practices and reduce the amount of sediment run-off into the reef.

Mr Frydenberg said the money would also go towards improving water quality, tackling the Crown-of-thorns starfish and scientific research.

"Millions of dollars will go into science and to better data management, and to be able to test the impacts on the reef," he said.

"We are looking at a whole range of new initiatives, taking best advice of the experts, working closely with the Great Barrier Reef Marine Park Authority, to ensure that the reef has its best chance into the future."

But despite the funding, Mr Frydenberg reaffirmed his position that global warming remained the biggest threat to the reef.

"We have seen right across the world a number of reefs being hit by this heat stress and this is combined here in Australia with also Cyclone Debbie as well as the Crown-of-thorns starfish," he said.

"So you have got lots of things happening at once, all of which are damaging to the reef. That is why we need a full core press."

Mr Frydenberg said despite coral bleaching events in recent years, the Great Barrier Reef was "remarkably resilient" and it was important for the world to know that.

"The reef supports some 64,000 jobs, over $6 billion it is worth to the economy and attracts more than two million visitors a year," he said.

"So it's a natural and national and international icon and that is why we're so determined to preserve it for future generations."