Great Barrier Reef Foundation chief executive Anna Marsden said the record $444 million grant from the Turnbull government to the charity was the best way to leverage private sector development to protect the natural wonder from climate change.

Despite criticism of Prime Minister Malcolm Turnbull and Environment Minister Josh Frydenberg signing off on the record funding agreement without an open tender, Ms Marsden said the not-for-profit organisation was best equipped to draw the best science, technology, research and conservation ideas to protect and restore the reef.