The first evidence of coral bleaching has emerged on Western Australia's Kimberley coast.

Key points: Several large bleached coral found at Broome's Reddell Beach

Several large bleached coral found at Broome's Reddell Beach People urged to use phone app to document bleaching

People urged to use phone app to document bleaching Marine scientists leaving Broome to inspect offshore bleaching

Marine scientists were anticipating one of the worst summers in history for coral bleaching, due to unusually warm waters, and extensive coral death has been seen on Queensland's Great Barrier Reef in recent weeks.

Sorry, this video has expired Coral bleaching can be seen at Broome's Reddell Beach

Over the weekend, Kimberley Marine Research Station director James Brown photographed several large, bleached corals at Reddell Beach in Broome.

"We've seen some signs of coral bleaching on the intertidal corals which have been exposed during the big tides," he said.

"What's important is that this appears to be quite a significant event.

"There's been coral bleaching before, and in fact small-scale coral bleaching is part of normal reef dynamics, but seeing large-scale coral bleaching is something that has not been reported ever before on the in-shore Kimberley coast.

"What we need people to do, is the local community in Broome, that gets an opportunity to see this, either through recreation or through work, reports it back to us, so we can get a sense of just how extensive and how severe the effects are."

Coral bleaching occurs when unusual conditions, such as warm temperatures, stress the coral, and kill off the tiny marine algae which give the coral its colour.

Reefs can recover over several years, but the increasing frequency of bleaching events mean some sections of reef have died.

Mr Brown is urging people to use a phone app, called CoralWatch, that has been developed by the Australian Marine Science Institute to document the current bleaching event.

"It's designed for citizen science, so it's quite simple for people to download the App, and while they're out they can load photos straight up, and make a comment," he said.

"You don't need to be a scientist. This is really an opportunity for everyone to be a part of this in getting our heads around something that I don't think any of us have seen before."

James Brown, director of the Kimberley Marine Research Station shows an example of coral bleaching at Broome's Reddell Beach. ( Supplied: James Brown )

First major trip to inspect offshore bleaching

The discovery comes as a team of marine scientists prepare to leave Broome on a two-week voyage to inspect the damage at offshore areas such as Scott Reef and Ashmore Reef.

Marine Scientist James Gilmour said the trip, aboard research vessel The Solander, will be the first opportunity to see first-hand how badly the more-remote reefs have suffered.

"We will be using a series of different methods to look at the bleaching, including diving and looking at the corals under the water," he said.

"But we will hopefully be incorporating some other methods, including AUVs [autonomous underwater vehicles], aerial surveys and possibly even satellite information to get a wide survey area across Western Australia."

He said even if the bleaching was not severe, it didn't mean the reefs were in the clear.

"We've had some of the hottest years on record and the consequences for the reefs are possibly catastrophic," he said.

"It takes many years, if not decades, for reefs to recover from severe bleaching events, and we're beginning to see cumulative bleaching events affecting the reefs within periods of a decade.

"So there's widespread concern and to some extent misery among the marine biology community, as we're starting to see the bleaching and death of coral reefs around Australia."