Coral grief
New Zealand Listener|November 04-10 2023
Coral reefs are noisy living animals vital to other marine life, particularly in the South Pacific. As the oceans warm, quick action is needed to reverse their decline.
NAT SELLERS
Coral grief

Once dazzling with colour O and life, coral reefs around the globe are turning a spectral white as climate change warms the world's seas. For Aotearoa New Zealand, this is not an immediate threat but for our South Pacific neighbours, the impacts are profound.

Simon Davy, professor of marine biology at Te Herenga Waka - Victoria University of Wellington, says Pacific coral reefs are declining at a rate of about 2% a year, and it may be only 40-50 years before they are completely gone.

With at least a quarter of all marine life found on coral reefs, their importance cannot be overstated. As Davy says, "The biodiversity is huge."

It follows that a healthy reef is one teeming with top predators. "The most healthy reef I've ever seen, Palmyra Atoll [northwest of Kiribati], is one of the remotest places on Earth and I've never seen so many sharks in my life," Davy says. However, even this lost corner of the planet occasionally gets bleached.

BLEACHED OUT 

"It depends where in the world, but when you start getting much above 30°C, corals tend to bleach and potentially die," he says. "Just one or two degrees above their normal summer temperatures, you're going to tip them over their physiological threshold."

When a coral bleaches, most of the algae that live in symbiosis within the coral die, leaving it without colour and its means to obtain food. If temperatures cool, a bleached coral has roughly a month for the algae to recover before its fate is likely sealed.

Another side effect of bleaching is that it reduces the coral's skeleton, making it more susceptible to erosion.

This story is from the {{IssueName}} edition of {{MagazineName}}.

Start your 7-day Magzter GOLD free trial to access thousands of curated premium stories, and 9,000+ magazines and newspapers.

This story is from the {{IssueName}} edition of {{MagazineName}}.

Start your 7-day Magzter GOLD free trial to access thousands of curated premium stories, and 9,000+ magazines and newspapers.

MORE STORIES FROM NEW ZEALAND LISTENERView all
First-world problem
New Zealand Listener

First-world problem

Harrowing tales of migrants attempting to enter the US highlight the political failure to fully tackle the problem.

time-read
3 mins  |
September 9, 2024
Applying intelligence to AI
New Zealand Listener

Applying intelligence to AI

I call it the 'Terminator Effect', based on the premise that thinking machines took over the world.

time-read
2 mins  |
September 9, 2024
Nazism rears its head
New Zealand Listener

Nazism rears its head

Smirky Höcke, with his penchant for waving with a suspiciously straight elbow and an open palm, won't get to be boss of either state.

time-read
2 mins  |
September 9, 2024
Staying ahead of the game
New Zealand Listener

Staying ahead of the game

Will the brave new world of bipartisanship that seems to be on offer with an Infrastructure Commission come to fruition?

time-read
4 mins  |
September 9, 2024
Grasping the nettle
New Zealand Listener

Grasping the nettle

Broccoli is horrible. It smells, when being cooked, like cat pee.

time-read
3 mins  |
September 9, 2024
Hangry? Eat breakfast
New Zealand Listener

Hangry? Eat breakfast

People who don't break their fast first thing in the morning report the least life satisfaction.

time-read
3 mins  |
September 9, 2024
Chemical reaction
New Zealand Listener

Chemical reaction

Nitrates in processed meats are well known to cause harm, but consumed from plant sources, their effect is quite different.

time-read
4 mins  |
September 9, 2024
Me and my guitar
New Zealand Listener

Me and my guitar

Australian guitarist Karin Schaupp sticks to the familiar for her Dunedin concerts.

time-read
2 mins  |
September 9, 2024
Time is on my side
New Zealand Listener

Time is on my side

Age does not weary some of our much-loved musicians but what keeps them on the road?

time-read
7 mins  |
September 9, 2024
The kids are not alright
New Zealand Listener

The kids are not alright

Nuanced account details how China's blessed generation has been replaced by one consumed by fear and hopelessness.

time-read
4 mins  |
September 9, 2024