From 'Watch' to 'Warning' — Norfolk Island's Reef

Out on A Swim

‘Out on a swim’ is a coral reef blog that tells the stories of the characters who live under the waves and what has caught my eye when ‘out on a swim’ in the lagoons of Norfolk Island. It is also a record of the difficulties Norfolk Island’s reef faces, like many others around the world, as a result of the poor water quality that has been allowed to flow onto it.

This blog is rated in the Top 20 Coral Reef Blogs in the world.

A screenshot notification of the warning levels for coral bleaching, received on 24 January 2025

Last week, the chance of coral bleaching in Norfolk Island’s inshore lagoons was raised from ‘Watch’ to ‘Warning’. Last year, we rose to Alert level 2 by February (these things happen fast, over a matter of a week or two), but fortunately, although we did get bleaching, it was nowhere near as bad as it could have been. I am keeping fingers crossed that this happens again this year. Although I am not sure we are going to get off so lightly this time.

In this post, I’ve included the change to our Alert level (right) and three images of the temperatures/bleaching for 2020–2021 (when we last had severe bleaching), 2023–2024, when the temps were up there but we got away with it, and 2024–2025 (bottom of this post). If you want to take a look at the Global Reef Watch site and have a look at the various graphs etc, go here: Coral Reef Watch.

It is interesting that back in 2020–2021, the temperatures were not as high as they were last year, yet the bleaching was bad. A lot has to do with the timing of the tides. When we get those low low tides in the hottest part of the day for a stretch of a few days, that is when it can get serious. So we need a break in the weather before those happen in a week or two.

So why do I worry about water quality all the time when bleaching seems inevitable these days, so the reef is probably doomed anyway?

Slaughter Bay, Norfolk Island, March 2020

Well, think of being in a boxing ring for the fight of your life. One punch and you can get back up. Two punches and it gets a bit harder. By three punches you are out on the floor with stars before your eyes and it is becoming increasingly difficult to get back up.

We need to stop punching the reef. We need to remove some of those stressors so it is more resilient for the inevitable blows that are going to come its way. It’s not difficult. We know what the problem is (thanks to CSIRO’s Water Quality report released in October 2024, which confirmed all the other reports and observations going back to the 1960s), we just need to act. And now it really is urgent.

The two photos in this post are of some bleached coral in Slaughter Bay, March 2020. Our most vulnerable colonies seem to be the pretty lace corals (Pocillopora), followed by the plate corals (Monitpora) and the porites.

The CSIRO report can be found here: Norfolk Island Water Quality Assessment. This report should be read together with the report on acid sulphatre soils, here: Acid Sulfate Soil Management in the Kingston and Arthur’s Vale Historic Area (KAVHA) on Norfolk Island.

Read more about the CSIRO report, here: Taking stock. Which way from here?

2024 to 2025

2023 to 2024

2020 to 2021

Jun 13, 2025

Glimpses of recovery: what the reef could be if we let it

Day 6 of this photo series from Norfolk Island coincides with the final day of the UN Ocean Conference in Nice. After a week of documenting decline, today’s post offers a different view – what reef recovery can look like when conditions improve. Drought in 2024 gave the reef a break, and the results were unmistakable: healthier corals, lower disease, and more fish. This is what’s possible if we act.

Jun 12, 2025

Warning signs: quiet and unnoticed collapse of two coral colonies

Day 5 of my blog series for the UN Ocean Conference: two long-lived coral colonies in Norfolk’s lagoon died quietly from disease. No drama – just slow collapse and overgrowth by algae. A reminder that not all reef losses are loud, but they are happening.

Jun 11, 2025

Warning signs: what Norfolk Island’s reef is telling us

Day 4 of a week-long photo series from Norfolk Island, shared during the UN Ocean Conference in Nice. Today’s post spotlights a Hydnophora pilosa colony where white syndrome appeared suddenly and spread quickly, taking out around a quarter of the coral. In the months that followed, algae quietly filled the gap – a subtle but telling shift from coral to algae that’s happening across the reef.

Jun 10, 2025

Warning signs: coral disease takes hold

In Day 3 of this blog post series, published while leaders gather at the UN Ocean Conference in Nice, we see Norfolk Island’s coral reef lagoon quietly delivering a stark warning: recurrent land-based pollution, coral disease, and delayed decisions are dismantling this ecosystem in real time.

Jun 9, 2025

Warning signs: coral growth anomalies – the slow cancers of the reef

Day 2’s post coinciding with the UN Ocean Conference looks at coral growth anomalies – sometimes called coral ‘cancers’. These slow-moving diseases quietly weaken coral colonies, making them far more vulnerable to storm damage and algal takeover. On Norfolk Island’s reef, I’ve watched this exact process play out over several years. This is how chronic stress silently dismantles coral ecosystems.

Jun 8, 2025

Warning signs: shifting baselines on Norfolk Island’s reef

Today is World Ocean Day — a timely moment to launch my week-long blog series on Norfolk Island’s reef. Each day this week, I’ll be sharing photo essays that document the slow but steady pressures reshaping this fragile reef. Today: how shifting baselines make us blind to what we’ve already lost.

Apr 29, 2025

The Governance–Government Vacuum: Norfolk Island’s Forgotten Ecology

A personal reflection on Norfolk Island’s coral reef environment, political denial, and what John Wyndham’s The Kraken Wakes can still teach us about slow-moving disasters — and why this election matters more than ever.

Feb 20, 2025

Cute as buttons – Astrea curta

Astrea curta corals are ‘small, moderately plocoid [flattened], distinct, and almost circular’ . Normally grey-green in colour, you can see from the images here, ours are often beautiful rich gold, although they do vary. They have a neat growth habit and button-like corallites, which can grow in columns, spherically or flattened. Large colonies of these can form gorgeous undulating bumps.

Jan 26, 2025

From 'Watch' to 'Warning'

Last week, the chance of coral bleaching in Norfolk Island’s inshore lagoons was raised from ‘Watch’ to ‘Warning’ and will more than likely rise to Alert levels one and two in coming weeks. So why do I worry about water quality all the time when bleaching seems inevitable these days and so the reef is probably doomed anyway? Read on to find out.

Jan 4, 2025

From little things – watching them grow

Small numbers of different fish species is not an unusual phenomenon on Norfolk Island’s reef, but it does demonstrate what a tiny, precious, coral reef ecosystem we have, when we can count individuals on one hand and watch each of them grow, like these little blackeye thicklips, a member of the wrasse family.