1. Great Barrier Reef authority confirms unprecedented sixth mass coral bleaching event

2. UN mission must see coral bleaching to get ‘whole picture’ of Great Barrier Reef, experts say

Aerial surveys show almost no reefs across a 1,200km stretch escaping the heat, prompting scientists to call for urgent action on climate crisis.

Underwater footage of bleached coral on the John Brewer Reef, from 1 February near Townsville. Australia’s Great Barrier Reef Marine Park Authority confirms the ocean icon has been hit with another mass coral bleaching event. — Great Barrier Reef hit by sixth coral bleaching event – video

The Great Barrier Reef has been hit with a sixth mass coral bleaching event, the marine park’s authority has confirmed, with aerial surveys showing almost no reefs across a 1,200km stretch escaping the heat.

The Guardian understands a United Nations mission currently under way to check the health and management of the reef will be briefed on the initial findings of the surveys as early as Friday in Townsville.

The confirmation from the Great Barrier Reef Marine Park Authority (GBRMPA) marks an alarming milestone for the ocean icon, with 2022 going down as the first time mass bleaching has happened in a cooler La Niña year which scientists had hoped would be a period of recovery for corals.

Government scientists said the confirmation showed the urgency of cutting greenhouse gas emissions that were driving the repeated mass bleachings.

A bleached plate coral on John Brewer reef off Townsville in February 2022

Dr David Wachenfeld, GBRMPA chief scientist, told the Guardian bleaching wasn’t expected in a La Niña.

“But having said that, the climate is changing and the planet and the reef is about 1.5 degrees centigrade warmer than it was 150 years ago. Because of that, the weather is changing. Unexpected events are now to be expected. Nothing surprises me any more.”

Aerial surveys, mostly using helicopters, were completed by the Australian Institute of Marine Science (Aims) and GBRMPA on Wednesday along the entire 2,300km length of the marine park covering about 750 individual reefs.

The marine park is divided into four management areas, and Wachenfeld said there was widespread bleaching in all four zones. “Therefore, we can confirm this is the fourth mass bleaching event since 2016 and also the first under La Niña condition,” he said.

Dr Neal Cantin, an Aims research scientist, led one of two observing teams and personally observed reefs from helicopters across 1,800km.

Between the Whitsunday Islands and Cooktown he said he “did not fly over a reef and score it as ‘no bleaching’”.

Reefs closer to the shore between the Whitsunday Islands to Cooktown had seen the most extreme bleaching, but the “spatial footprint of severe bleaching is very wide”.

Most reefs along that stretch were recorded as “severe”, which means at least 60% of an individual reef’s corals had bleached. Some of those reefs also had corals that had bleached and then died in the last few weeks.

But even within this, there was variability between reefs and across individual coral colonies. Bleaching in the southern section of the marine park was much milder than elsewhere, and there were some reefs there with no bleaching at all.

Coral bleaching happens when the animal becomes stressed from above-average water temperatures. The coral animal expels the algae that lives inside them and provides the coral with food and colour.

Corals can survive bleaching and Cantin said between now and the end of the year, scientists at Aims and elsewhere would be carrying out in-water checks to see how many corals survived and regained their colour.

Widespread mass bleaching of corals on the reef was first seen in 1998, and happened again in 2002, 2016, 2017, 2020 and now 2022.

Coral bleaching on the John Brewer Reef, which is offshore from Townsville in the Great Barrier Reef Marine Park. Queensland. Australia. Dr Adam Smith dives on the reef.

Scientists started raising the alarm for this year’s event as early as December, when ocean temperatures over the reef hit a record high for that month.

Studies have shown that heat stress can have several “sublethal” effects on corals, including making them more susceptible to disease, slowing their growth and limiting their ability to spawn.

Cantin said it appeared this year’s bleaching had covered a wider area than back-to-back outbreaks in 2016 and 2017, but the intensity of the heat was broadly lower than those years.

“The fact that we are seeing a mass bleaching event in a La Niña year is concerning and a clear sign of the increasing intensity of climate change and ocean warming,” he said.

“I’m extremely concerned – beyond concerned. We need action immediately. We are on bleaching watch every year. The spacial footprint of severe heat is increasing at an alarming rate. It’s also happening faster than was predicted 20 years ago. The severity and frequency is very alarming.”

North of Cooktown many reefs are dominated by a family of boulder-shaped corals called porites, some of which can grow several metres wide and live for centuries. Some porites had bleached, Cantin said.

He said the bleaching along the whole reef strongly overlapped satellite observations of heat stress and ocean temperature from the US government’s National Oceanic and Atmospheric Administration.

Wachenfeld said climatologists would study the factors that drove this year’s bleaching to establish statistical probabilities of it happening under a changed climate.

“But in my experience, this could not have happened without climate change,” he said. “We need to see [these events’] as the reef ringing a very loud alarm bell about the impacts of climate change.

“The reef remains a vast and resilient ecosystem. Despite the concerns that we have when we see a climate-driven impact like this, we have to maintain determination and hope for the future.

“But that determination and hope has to be based on the strongest and fastest possible action to reduce greenhouse gas emissions globally and the ongoing commitments of governments, the community and industry to protect the system.”

Two scientists – one from Unesco and another from the International Union for Conservation of Nature – will be briefed on the findings of the aerial surveys in the coming days as part of their 10-day monitoring mission.

The mission, which started with briefings in Brisbane on Monday, will compile a report to go before the next world heritage meeting currently scheduled for June.

Last year, scientific advisors at Unesco recommended the reef be placed on a list of world heritage sites “in danger” because of impacts from climate change and slow progress on improving water quality.

But fierce and sustained lobbying from the Morrison government saw the 21-country committee go against that advice. The committee said it wanted to see Australia accelerate efforts on climate change through its reef policy.

Australia requested Unesco carry out the monitoring mission, but the UN agency is keeping details of the mission confidential.

Conservation groups and the government’s own reef envoy, Cairns-based MP Warren Entsch, have said the UN mission should be taken to see the bleaching.

2. UN mission must see coral bleaching to get ‘whole picture’ of Great Barrier Reef, experts say

Government’s reef envoy says visiting scientists ‘have to see the good and the bad’ as widespread bleaching confirmed

A UN mission under way in Queensland to see if the Great Barrier Reef should be put on an “in danger” list will not get “the whole picture” unless it visits reefs currently experiencing coral bleaching, conservationists and the government’s own reef envoy have said.

Details of the 10-day mission, which began on Monday in Brisbane, are being kept confidential and the locations to be visited have not been formally disclosed.

But Guardian Australia understands briefings started in Brisbane, and visits to Lady Elliot Island on the reef’s southern tip, as well as time in Cairns and Townsville, are on the agenda.

The Great Barrier Reef Marine Park Authority (GBRMPA) is due to complete aerial bleaching surveys across the 2300-kilometre reef before the end of this week.

The Great Barrier Reef is not on the ‘in danger’ list. Why, and what happens next?

The authority’s chief scientist, Dr David Wachenfeld, has confirmed bleaching is widespread but variable, saying the flights will give a clearer picture of how the event compares with five previous mass bleachings.

Fierce lobbying from the Morrison government last year saw the 21-country World Heritage committee ignore a Unesco recommendation that the reef be placed on a list of sites “in danger”, mainly because of impacts from the climate crisis.

Instead, the committee asked Australia to renew its cornerstone Reef 2050 policy so that it “addresses the threat posed to the property by climate change” and said it was concerned progress in cutting pollution running off farms and grazing areas was too slow.

Australia requested the mission be carried out and the government’s reef envoy, MP Warren Entsch, said it should visit reefs currently bleaching.

“They couldn’t see the whole picture unless they did,” he said. “There should be no whitewashing. They have to see the good and the bad.”

Entsch, whose Leichhardt electorate centres on the reef tourism hotspot of Cairns, said he would meet with the mission.

“I’ve heard reports of significant bleaching [on some reefs] but also of no bleaching whatsoever. We have to acknowledge the vast area totally unimpacted by this and areas where we have seen magnificent growth [in corals].”

Entsch said the mission would be briefed by scientists from the Australian Institute of Marine Science, as well as reef managers at the marine park authority, traditional owner groups and tourism operators.

“They will talk to top scientists who have to make the decisions that we base our funding on,” he said.

The aerial surveys will confirm if multiple reefs have bleached in at least two of the park’s four management areas, which Wachenfeld said would constitute a “mass bleaching” event.

Over a 250km stretch in the reef’s central region, north and south of Townsville, most reefs have bleached severely – where at least 60% of corals on a reef turn white – Wachenfeld said last week. Some corals had already died.

Widespread mass bleaching of corals was first seen in 1998, and happened again in 2002, 2016, 2017 and 2020. One study has said 98% of the 3,000 individual reefs that make up the entire system have been hit at least once by bleaching.

The reef has never seen widespread bleaching in a La Niña year before – the phase of a cycle of ocean temperatures in the Pacific that should keep the region cool enough for corals to escape bleaching.

Unesco and the Morrison government have kept details about the mission under wraps. It is being carried out by one scientist from Unesco and another from the International Union for Conservation of Nature (IUCN).

Guardian Australia has confirmed the first formal briefings took place on Monday and Tuesday inside the Queensland government’s offices in Brisbane. On Tuesday, Greenpeace staged a protest outside.

Greenpeace protesters outside government offices in Brisbane where a Unesco monitoring mission is being briefed on the health of the Great Barrier Reef before travelling to different parts of it — Greenpeace protesters in Brisbane on Tuesday. Climate campaigner Martin Zavan said the organisation’s efforts to meet the Unesco mission had been “dismissed or ignored”. Photograph: Bianca Vitale/Greenpeace

Representatives were briefed from four reef advisory groups that include scientific experts, community and industry stakeholders, tourism operators and traditional owners.

“We MUST respect this earth - it is all we have

Claudio Dametto - South Australia

“I will always Vote to Preserve Our World.

Liam McGregor - Western Australia

“A simple message that even a politician can understand

Felicity Crombach - Victoria

“Please show you care about our future generations!!

Phil Harmer - New South Wales

“Save our world , Life & health before profits.

Kerry Lillian - New South Wales

“Close down all coal mines and Do not mine gas . Make these Companies

Daniel Johnson - New South Wales

“We want carbon free energy!

Edan Clarke - New South Wales

“Feels good to be taking a voter action step

Beaver Hudson - New South Wales

“Great Initiative. Let’s Hold elected officials Accountable to their bosses, us!

John Paul Posada - New South Wales

“We need actions not words we need honest democratic govt We need a pm

Bob Pearce - South Australia

“Thank you for this great resource. I was feeling helpless. Even this small step

Silvia Anderson - Victoria

“If political parties continue receiving political donations, we will rarely have politicians working for

Dan Chicos - New South Wales

“I only vote for people who will take urgent action to restore a safe

Susie Burke - Victoria

“Current government is not representing the opinion of the majority of Australian to meet

Neil Price - Tasmania

“We are fighting to rescue our kids' future from those who seek to steal

Vanessa Norimi - Queensland

“No time to waste Now or Never My vote is for NOW

Rosalie White - Victoria

“I am only 9 but I already care

Ava Bell - New South Wales

“From New Lambton Uniting Church - Caring for our world is a moral imperative.

Niall McKay - New South Wales

“Our federal govt is an International climate Embarrassment - its about time they stepped

Oriana Tolo - Victoria

“Vote earth this time!

Sue Cooke - Queensland

“We are in one on the wealthiest countries in the world. we have the

rowan huxtable - New South Wales

“The climate Emergency is the public health opportunity and urgent priority of the 21st

Mike Forrester - Victoria

“If they want my vote they better act now

Barbara McNiff - New South Wales

“We need to act locally now for the earth. Our only home. Vote Earth

Anne Miller - New South Wales

“I often look at the places I've known all my life and see how

Jim Baird - New South Wales

“Strike one For people power!!! Democracy might prevail outside the current cronyism that faces

Lorraine Bridger - New South Wales

“Our federal politicians Are Afraid to make action on climate change a major election

Jennifer Martin - New South Wales

“climate election, let's go!

Fahimah Badrulhisham - New South Wales

“Great to see this website that is a focus on action for climate change

Lynette Sinclair - New South Wales

“Let’s show politicians and the Murdoch media that climate change is by far the

Jane Aitken - Australian Capital Territory

“If you want to stay in power You need to take action to stop

Jane Bulter - New South Wales

“We are all that stands between terminal climate change and the vulnerable. We are