By Alistair Bates, ABC<\/p>\n
<\/p>\n
\nCyanobacteria and disease has begun to grip the remaining coral.
\nPhoto: Supplied: David Juszkiewicz via ABC\n<\/p>\n
On Western Australia’s Ningaloo Reef, the shift from stark white to sickly brown paints a dire picture.<\/p>\n
“It’s a really dramatic change from all the colour and the vibrancy that a healthy coral shows,” marine scientist Zoe Richards said.<\/p>\n
“We’ve shifted to this dull phase where it’s algae dominating the corals.”<\/p>\n
The most recent survey by researchers from Curtin University shows that more than 60 percent of corals at eight sites, largely in the reef’s northern lagoon, have died.<\/p>\n
Of the 1600 corals counted in March, only 600 were still alive come late October.<\/p>\n
The findings mark a new phase for the World Heritage site, which was gripped by its worst-ever bleaching event earlier this year.<\/p>\n
Scientists warn ocean temperatures off WA are already warmer than average, with the summer months set to be “incredibly critical” for the remaining corals to hang on.<\/p>\n
Coral bleaching vs mortality<\/p>\n
When the ocean get too hot, corals expel the zooxanthellae algae that lives in their tissue.<\/p>\n
These microorganisms give corals their bright pastel colours and resistance to disease.<\/p>\n
Their absence creates the bleaching effect many Australians have become all too familiar with.<\/p>\n
Unlike its east coast cousin, the Great Barrier Reef, the 270-kilometre Ningaloo Reef largely escaped the impact of climate change-induced ocean warming.<\/p>\n
But a record heatwave persisting since December 2024 flipped that fact in the extreme.<\/p>\n
“The corals that were bleached earlier in the year have unfortunately succumbed to the heatwave and they have died,” Dr Richards said.<\/p>\n
“Now, they are literally turned to rock with algae growing on top of them, it’s very sad.”<\/p>\n
Left ‘speechless’<\/p>\n
PhD candidate David Juszkiewicz said it was not until researchers explored the reef at depth that they realised the extent of the decay.<\/p>\n
“It’s when you scuba-dive and go down, you realise that there’s a lot of death underneath,” he said.<\/p>\n
Juszkiewicz compared the scene to walking through a forest after a bush fire.<\/p>\n
“All the understorey vegetation, everything is burnt-out and charred,” he said.<\/p>\n
“We’re speechless. There [are] no words that can explain what we saw.”<\/p>\n
<\/p>\n
\nSome species are thought to be totally extinct from the reef.
\nPhoto: David Juszkiewicz via ABC\n<\/p>\n
Dr Richards said the ripple effect of the coral death was yet to be understood.<\/p>\n
“We’ve lost a lot of the diversity on the reef, the complexity,” she said.<\/p>\n
“The coral is providing habitat for fish, for crustaceans, for shells, for worms \u2026 it’s quite likely they have all died.”<\/p>\n
Dr Richards said the death of the corals was “just the beginning”.<\/p>\n
“This summer and all the summers to come over the next decade are incredibly critical for these reefs to recover,” she said.<\/p>\n
There was some hope, however, with corals in the nearby Exmouth Gulf showing signs of resilience.<\/p>\n
Crucial window ahead<\/p>\n
The creep of rising water temperatures was first detected off WA’s coast about a year ago.<\/p>\n
Principal research scientist at the Department of Biodiversity, Conservation and Attractions Tom Holmes said the summer months were expected to be less severe.<\/p>\n
The department’s marine science team is in Exmouth conducting surveys of their own.<\/p>\n
“At the same time, in November of 2024, we were already seeing significant build-up of heat stress in the Kimberley, north-west atolls, and even down into the northern Pilbara,” Holmes said.<\/p>\n
“We’re looking probably slightly above average coming into [this] summer, but in the range of 0.4 to 0.8 degrees.<\/p>\n
“It probably wouldn’t move into the bleaching threshold categories \u2026 [although] these are still predictions at this point in time and things can change.”<\/p>\n
Pockets of hot water holding on from last year’s event remained a concern, particularly in the state’s south.<\/p>\n
“A lot of residual heat was actually retained down in the south-west of WA and that really hasn’t cooled coming into this new summer,” Holmes said.<\/p>\n
“So, we’re already looking down at the south-west and seeing some significant heating already starting to occur there.”<\/p>\n
Rallying for action<\/p>\n
Exmouth glass-bottom boat tour operator Craig Kitson said the rotting corals had left him feeling “absolutely helpless”.<\/p>\n
“The best way I can describe it is if you went out in your backyard and you saw your backyard dying and you didn’t know why and there’s no fix for it,” he said.<\/p>\n
Last week Kitson joined a delegation of regional Australians invited to Canberra by the Australian Conservation Foundation to lobby for stronger environmental protection reforms.<\/p>\n
He said the situation on the Ningaloo Reef threw the federal Coalition’s decision to formally drop its net-zero commitment in sharp relief.<\/p>\n
“It’s going to need some strong leadership to make the right move because we’re staring down the barrel of of the pointy end of climate change,” he said.<\/p>\n
– ABC<\/p>\n","protected":false},"excerpt":{"rendered":"By Alistair Bates, ABC Cyanobacteria and disease has begun to grip the remaining coral. Photo: Supplied: David Juszkiewicz…\n","protected":false},"author":2,"featured_media":142859,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3],"tags":[48,47,42,43,49,46,44,45,40,38,41,39],"class_list":["post-142858","post","type-post","status-publish","format-standard","has-post-thumbnail","category-headlines","tag-audio","tag-current-affairs","tag-headlines","tag-news","tag-podcasts","tag-public-radio","tag-radio-new-zealand","tag-rnz","tag-top-news","tag-top-stories","tag-topnews","tag-topstories"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/posts\/142858","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/comments?post=142858"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/posts\/142858\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/media\/142859"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/media?parent=142858"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/categories?post=142858"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/tags?post=142858"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}