Evidence has emerged for the first time that coral bleaching, which has devastated the Great Barrier Reef, extends along the northern Australian coast.

Marine scientists are midway through a two-week voyage to inspect the major reef networks off Western Australia's Kimberley coastline.

James Gilmour, who is heading up the voyage for the Australian Institute of Marine Science (AIMS), said they had discovered more reefs that were badly damaged.

"We came out to the reef expecting from temperature predictions that there would be coral bleaching, and indeed that's what we've found," Dr Gilmour said.

"It's a bleak view up here. We've seen coral bleaching at many of the sights we've surveyed, and we've seen 60-90 per cent of the corals bleached."

The AIMS team has been diving on the Scott and Seringapatam reefs, which are located in the Timor Sea, about 400 kilometres north-west of Broome.

Underwater photographs show the once-colourful coral now ghostly white.

Bleaching occurs when heat-stress causes the colourful algae that lives in coral to be expelled.

In the months leading up to summer, scientists warned of what could be the worst bleaching event in history, due to unusually warm conditions and the El Nino system.

So far on the trip, water temperatures of 33 degrees Celsius have been recorded at Scott Reef. Even at 50 metres underwater, temperatures around 30 degrees are being recorded.

Divers inspected Scott Reef as part of a two-week voyage off the WA coast. ( Supplied: Nick Thake )

Bleaching getting worse, scientist says

Dr Gilmour said coral could recover from bleaching, but only with a decade free from heat stress.

"In the past when we've seen these kinds of events happen, which was only once before in 1998, it took between 10 and 15 years to recover," he said.

The research team will also inspect Rowley Shoals for bleaching damage. ( ABC News: Erin Parke )

"The concern for us however at the moment is that with climate change and environmental change, we're seeing a greater increase in disturbances, so whether the reefs can recover over another 10 or 15 years really depends on what happens during that time."

Dr Gilmour said the most concerning thing was that the bleaching appeared to be worsening daily.

"The changes in the reef that we've seen while we've been here indicate it's an ongoing process," he said.

"So we arrived about a week ago, and there was certainly less bleaching evidence than there is at the moment."

The eight-person crew is onboard the research vessel The Solander.

The team is planning to move on to Rowley Shoals to inspect the level of bleaching damage there.

It was revealed on Wednesday that aerial and underwater surveys of the Great Barrier Reef had shown 93 per cent of it has been bleached to some extent.