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Norfolk Island's Reef

Discover a fragile paradise – Norfolk Island's beaches, lagoons and coral reef
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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 page shows the most recent blog posts. For the complete catalogue, visit the ‘Out on a swim index’ page.

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

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

June 13, 2025

Over the past week, while the UN Ocean Conference unfolded in Nice, I’ve shared a daily series of photo essays from the opposite side of the world – Norfolk Island – where our tiny coral reef lagoon is showing all the warning signs of ecosystem decline.

This inshore reef, small enough to monitor closely and simple enough to track change clearly, has revealed a pattern: disease and algal overgrowth – all linked to poor water quality and long-standing land-based stressors. It’s a microcosm of what’s playing out on reefs around the world.

But today, for the final post, I want to show the other side of that story.

During the drought of 2024, anecdotally, corals began to recover. Disease rates dropped. Growth improved. Fish returned. These images are a glimpse of what Norfolk’s reef can still be – and could be more often – if we reduce the pressures coming from the land.

The warning signs are real. But so is the reef’s capacity to recover. What happens next is up to us.


Day 6 – A rare window into reef resilience

This week, I’ve shared some difficult stories from Norfolk Island’s reef – coral colonies lost to disease, one after another, each telling part of a bigger story of stress, decline, and silence. But today, for the final post in this series, I want to show you something else.

There are places in Emily and Slaughter Bays – particularly in the more sheltered corners and along certain ledges – where the corals are thriving. These aren’t just surviving colonies. Some are spectacular – with strong colour, good growth, and very little sign of disease. Much of this improvement coincided with the long dry period of 2024. Without the regular flow of fresh – and often polluted – water from the land, the reef was able to breathe again. Corals that had been struggling began to look visibly healthier. Disease dropped off. Growth picked up. Anecdotally, we saw more fish. We recorded more ‘new’ (to here) species for the first time. The reef felt different.

It was a glimpse – a window into what the lagoon could look like more often, if the pressures were reduced.

But here’s the catch. Nothing else changed. The water quality threats – excess nutrients, sewage, runoff – are all still there. So when the rains return, and the creeks flow again, we’re right back where we started.

As I said in my the second post of this six-day series, ‘Warning signs: coral disease takes hold’, in 2022, a team of researchers described Norfolk Island’s reef as among the most diseased in the world:

“In December 2020 and April 2021, we observed 60% of surveyed Montiporid coral colonies with signs of disease – a prevalence in line with the most severe coral disease outbreaks recorded to date worldwide.”
(Page et al., 2022)

That was a wake-up call. What we’ve seen since should be, too. But today’s images are here to remind us that recovery is possible. That this reef still has fight in it. That if we reduce the stressors – especially the flow of nutrients and contaminants from land – we can turn things around. We’ve seen it happen.

Now we need to act like it matters.

Above and below: Beautiful corals just metres from the shore on Norfolk Island’s reef

UN Ocean Conference 2025, blog blitz

Below is a list of the stories published this week, which together point to a reef under stress, a problem found all around the globe, but one that is within our capacity to fix:

  • Day 1: Warning signs: shifting baselines on Norfolk Island’s reef

  • Day 2: Warning signs: coral growth anomalies – the slow cancers of the reef

  • Day 3: Warning signs: coral disease takes hold

  • Day 4: Warning signs: what Norfolk Island’s reef is telling us

  • Day 5: Warning signs: quiet and unnoticed collapse of two coral colonies

  • Day 6: Glimpses of recovery: what the reef could be if we let it

In Environmental degradation Tags UNOceanConference, UNOC2025, Coral disease, corals, coral reef, coral health, Water quality
← Poop powerWarning signs: quiet and unnoticed collapse of two coral colonies →
Featured
18 Jun 2025 (20)_crop.jpg
Mar 7, 2026
Alveopora or flowerpot coral – how to tell the difference
Mar 7, 2026

They look alike at first glance, but Alveopora and flowerpot corals are not the same. The easiest way to tell them apart is to count the tentacles.

Mar 7, 2026
Norfolk’s lagoonal reef – the 2025 report, in plain English
Feb 27, 2026
Norfolk’s lagoonal reef – the 2025 report, in plain English
Feb 27, 2026

We now have the 2025 Norfolk Island reef health report, so I’m taking the opportunity to translate it into plain English here. Sadly, it’s more of the same story in Emily and Slaughter Bays – a reef that can cope with some stress, but is being asked to cope with too much, too often.

Feb 27, 2026
Halimeda’s night shift – why this reef algae changes colour
Feb 20, 2026
Halimeda’s night shift – why this reef algae changes colour
Feb 20, 2026

Halimeda is a calcareous green reef alga that forms new segments overnight, shifts from white to bright green by dawn, then pales again as calcification begins. A quick look at one of the reef’s smartest algae.

Feb 20, 2026
Reef real estate – a bubble-tip’s six-year stand-off
Jan 11, 2026
Reef real estate – a bubble-tip’s six-year stand-off
Jan 11, 2026

Reef space is finite, and nothing ‘shares’ it politely. This short photo essay follows one bubble-tip anemone on Norfolk Island’s lagoonal reef as it holds a crater surrounded by Montipora. The coral builds a rim; the anemone holds the centre. Six years apart, and the argument continues.

Jan 11, 2026
A year in review – 2025 on Norfolk Island's reef
Dec 28, 2025
A year in review – 2025 on Norfolk Island's reef
Dec 28, 2025

Norfolk Island’s reef in 2025 – a year in review. From NOAA bleaching alerts and the UN Ocean Conference ‘Warning Signs’ series to post-drought coral recovery and a wet winter revealed in long-term rainfall records, this post captures the wins, losses, and shifting baselines beneath the lagoon. Includes reef photos, highlights from Reef Relief, and standout stories from 2025 – from coral health and disease to boxfish biomimicry, sea urchins, nudibranchs, and heat-stress signals in anemones.

Dec 28, 2025
Herbicides, heritage, and an inshore reef: what happens when land management meets lagoon health
Dec 15, 2025
Herbicides, heritage, and an inshore reef: what happens when land management meets lagoon health
Dec 15, 2025

Herbicide use near Emily, Slaughter and Cemetery Bays raises questions about inshore reef health, heritage land management, and environmental protection on Norfolk Island.

Dec 15, 2025
Signs of bleaching – 8 December 2025
Dec 8, 2025
Signs of bleaching – 8 December 2025
Dec 8, 2025

I took these photographs this morning, Monday, 8 December 2025. A few warm days of settled weather, little cloud cover and low tides in the hottest part of the day have led to some early bleaching on our reef. Bleaching doesn’t always mean death for our corals, but it is concerning to have this so early in the summer season. Fingers crossed the conditions don’t last and the reef can recover.

Dec 8, 2025
Nature is my teacher
Dec 3, 2025
Nature is my teacher
Dec 3, 2025

This is a thank-you note. Five years after my first Out on a swim post – written with zero marine science quals and a head full of questions – I’m still in the water, now as a PhD candidate, because an extraordinary mix of locals, volunteers, researchers and public servants decided to share what they knew. This is the story of how nature – and a very patient community – became my teachers.

Dec 3, 2025
Reef grief: what dredging has done to other reefs
Nov 30, 2025
Reef grief: what dredging has done to other reefs
Nov 30, 2025

From Miami to Fiji, from Dubai to tiny village harbours on atolls, dredging near coral reefs has left a long trail of scars – even on ‘small’ projects. This follow-up to last week’s Kingston post walks through real examples of what happened elsewhere, and what that should make us think about before we dig up our own reef.

Nov 30, 2025
To dredge or not to dredge? The Kingston Pier channel project
Nov 20, 2025
To dredge or not to dredge? The Kingston Pier channel project
Nov 20, 2025

How much risk are we really taking with the planned dredging at Kingston Pier – and how much protection do our corals actually have on paper? This piece walks through what the federal approval does and doesn’t guarantee, explains why sediment and light matter so much to the reef, and asks the hard questions we need answered before we trade a deeper channel for a shallower future.

Nov 20, 2025

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