A defiant Pauline Hanson has told the Great Barrier Reef Marine Park Authority's top scientist coral bleaching is a natural occurrence, rejecting its link to heat waves.
The Queenslander used a Senate estimates hearing on Monday to question the link between extreme heat and back-to-back mass coral bleaching events in 2016 and 2017.
"You're saying that coral bleaching is affected by water temperatures," she told David Wachenfeld.
"Yet around Indonesia, closer to the equator ... where the water temperatures are 29 degrees, it's a known fact that coral actually grows faster and more prolific in warmer temperatures."
Dr Wachenfeld explained that corals live in a variety of water temperatures over the world, with substantial differences even within the Great Barrier Reef.
Corals bleach when stressed - such as when exposed to warmer than normal temperatures - and die if stressed for prolonged periods, he told the senator.
"The fact that corals in Indonesia could withstand higher temperatures than corals on the central Great Barrier Reef is of no benefit to the corals of the central Great Barrier Reef when they die."
But Senator Hanson was not swayed, asking how the authority planned to address both water temperatures and the "natural occurrence" of bleaching events with its taxpayer funding.
The GBRMPA is trying to stamp out crown-of-thorns starfish and improve water quality in catchments while urging for greater global action on climate change, Senator Hanson was told.
The authority's recently-released five-year outlook for the reef found it to be "very poor" unless more action is taken to slow climate change.
Senators were also told Liberal MP Warren Entsch will present two reports each year to the environment minister in his role as special envoy for the reef.
The reports will focus on community and industry views towards the reef, while his broader role leans towards promoting the government's existing management of the protected area.
The special envoy role is "colossal bullshit" to distract from the help the reef needs, Greens senator Peter Whish-Wilson said after hearing the role's description.
Mr Enstch, whose electorate includes the Great Barrier Reef, has been vocal in his belief that it does not need saving but needs to be managed well.
Senators also heard the Great Barrier Reef Foundation - controversially handed close to $444 million in taxpayer money last year - had raised $21 million on its own for projects.
The government had justified funding the charity due to its ability to leverage further investment from the private sector.
Australian Associated Press