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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.

The flowerpot coral, Genus Goniopora, Norfolk Island, which I thought was a sea anemone (below)!

Nature is my teacher

December 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.

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In Education Tags blog, Environmental protection, advocacy, Norfolk Island, coral reef, coral health
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Aerial image of Kingston Pier and the west end of Slaughter Bay, Norfolk Island. This map includes data from Airbus Imagery from the dates:20/06/2023–12/09/2023.

Reef grief: what dredging has done to other reefs

November 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.

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In Environmental degradation, Corals, History, Recreation Tags Norfolk Island, dredging, World Heritage, corals, Environmental protection, marine environment, marine conservation
2 Comments

A view to the west of the historic Kingston Pier, which directly adjoins the coral reef lagoon system of Emily and Slaughter Bays. The dredge site is on its east and southern sides.

To dredge or not to dredge? The Kingston Pier channel project

November 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.

Read More
In Environmental degradation, Corals, History, Recreation Tags Norfolk Island, dredging, World Heritage, corals, Environmental protection, marine conservation, marine environment
2 Comments

Eclipse butterflyfish – Chaetodon bennetti, Norfolk Island

Celebrating Biodiversity Month on Norfolk Island

September 7, 2025

September is Biodiversity Month – the perfect time to celebrate the astonishing variety of life on Norfolk Island’s reef. From new fish sightings to coral mosaics, every observation is a reminder of how much there is still to learn and protect.

Read more about why biodiversity matters, globally and right here in our lagoon.

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In Biodiversity Tags biodiversity, Fish, corals, Norfolk Island, Emily Bay, Slaughter Bay
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Mr Lemonhead, the yellow boxfish (Ostracion cubicus) 8 August 2025, Norfolk Island

Biomimicry: How a Boxfish Caught Mercedes Benz’s Eye

August 10, 2025

Meet Mr Lemonhead – our lagoon’s teeny yellow boxfish with a big design legacy. He inspired a Mercedes Benz concept car, proving how nature is full of surprises. And he shares the lagoon with other critters whose tricks have also shaped real-world inventions.

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In Fish Tags Fish, fish species, Norfolk Island, Mercedes Benz, biomimicry, design
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Hynophora pilosa colony, Norfolk Island

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

June 11, 2025

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.

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In Environmental degradation Tags corals, coral reef, Norfolk Island, White syndrome, coral disease, UNOceanConference, UNOC2025, Water quality
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Cute as buttons – Astrea curta

February 20, 2025

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.

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In Corals Tags corals, Astrea curta, Norfolk Island, Emily Bay, Slaughter Bay
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Slaughter Bay, Norfolk Island, March 2020

From 'Watch' to 'Warning'

January 26, 2025

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.

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In Corals Tags corals, coral bleaching, heatwave, resilience, water quality, Norfolk Island
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From little things – watching them grow

January 4, 2025

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.

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In Fish Tags fish, fish species, Blackeye thicklip, iNaturalist, Norfolk Island, coral reef
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Emily Bay at low tide, early morning, December 2024

A year in review – 2024 on Norfolk Island’s Reef

December 27, 2024

It is five years since I began wielding a camera underwater in Norfolk Island’s lagoons and my third ‘year in review’ for this ‘Out on a swim’ blog. And what a journey it has been. At least this year I have some great news to report, but – a bit like a curate’s egg (partly bad and partly good) – there are also some downers. Find out what 2024 has meant for Norfolk Island’s reef.

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In Environmental degradation Tags Norfolk Island, coral reef, corals, coral health, water quality, environment, environmental protections
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The Emily Bay’s massive ‘brain’ coral, Paragoniastrea australensis, photographed on 6 July 2024

While you were sleeping ...

July 10, 2024

This massive and incredibly slow-growing Paragoniastrea australensis sits in Emily Bay on Norfolk Island and is one of our most recognisable bommies. While all looks reasonably calm during the day, at night, while you are sleeping, the surface of the coral colony seethes with millions of tiny tentacles busily reaching out to find food, while others aggressively ward off opportunistic interlopers.

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In Corals Tags corals, coral reef, bommie, Emily Bay, Norfolk Island
Comment

The view across Emily Bay and Slaughter Bay’s contiguous reef at low tide. Quintal’s Passage can be seen as two parrallel lines of rocks. It runs from Emily out to sea.

Blasting a passage through the reef, Norfolk Island

April 6, 2024

We have shaped Kingston, Norfolk Island, to suit our own ends, whether it is by draining the swamp, undertaking major earthworks, or by using it for agriculture and grazing. Our interventions have placed the reef at risk. But simultaneously, the confluence of human activity and a unique natural environment have created a place of incredible significance, which deserves some special management to preserve all its facets.

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In Ecosystem Tags Kingston, World Heritage Area, Norfolk Island, Water quality, Quintal's passage, coral reef, coral health, coral disease, Colonial settlement
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High tide and pounding waves on Norfolk Island’s coral lagoon, southern shore, looking east towards Point Hunter

Norfolk Island reef's autopsy reports

March 3, 2024

More reports to add to a long catalogue of reports were delivered to the general public over the last few days on Norfolk Island’s water quality and reef health. Reassuringly, they all say the same thing. Our poor water quality is affecting the health of our reef. So the science must be good! So when are we going to do something about it?

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In Environmental degradation Tags water quality, reports, Norfolk Island, coral health, coral disease, World Heritage Area
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Green moon wrasse, Emily Bay, Norfolk Island

I only have fish eyes for you!

February 22, 2024

Do fish have eyes that move independently? Well, no, not really, but, yes, sort of, in some species, sometimes!

Read on for a brief ‘Fish eyes 101’ summary of how they work.

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In Fish Tags fisheye, Fish, fish species, anatomy, Norfolk Island, Emily Bay
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A territorial banded scalyfin, Parma polylepis (aatuti), Norfolk Island

Know your damsels – multispine damselfish versus banded scalyfins

February 7, 2024

The banded scalyfins and the multispine damselfish are arguably two of the most common species in Norfolk Island’s lagoons. People often confuse them, particularly the juveniles, so here are some photos to clarify which are which. Once the differences have been pointed out, you’ll never confuse them again.

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In Fish species Tags fish species, fish, damselfish, aatuti, Norfolk Island
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Norfolk Island’s inshore reef during low tide and at sunrise

A year in review – 2023 on Norfolk Island's reef

December 29, 2023

Sadly, the year didn’t bring any obvious improvements to Norfolk Island's reef in terms of reductions in incidences of coral disease, or runaway algal growth. And while some fish seem to have departed the scene, another species has re-established its home. Here’s a rundown of what I've been doing during the last four years of observations, and what I've seen happening on our reef in 2023.

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In Ecosystem Tags 2023, Norfolk Island, coral reef, Fish, fish species, water quality, coral health, White syndrome
4 Comments

Free weed!

December 22, 2023

I couldn’t resist posting these beautiful images of floating seaweed. Enjoy!

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In Biodiversity, Algae Tags seaweed, algae, Norfolk Island
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Acropora coral, Norfolk Island, 14_StairwayReef, 14 November 2021

The journey from coral reef to rubble

December 16, 2023

For two years, I have stopped by and photographed this beautiful Acropora coral formation in Emily Bay on Norfolk Island. In my database for this colony, I called the folder 14_StairwayReef; 14 for the geographic location on a map, followed by my romantic name for it. Today it is just so much rubble.

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In Environmental degradation Tags corals, coral reef, White syndrome, coral disease, Norfolk Island
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White syndrome on a Hynophora pilosa colony, Norfolk Island, 23 November 2023

The spatiotemporal dynamics of a coral disease

December 9, 2023

A pictorial study of the spread of white syndrome, over time, in a Hynophora pilosa colony on Norfolk Island. This beautiful coral colony is in the middle of the channel that runs between the contiguous Emily and Slaughter Bays, in Norfolk Island’s inshore coral reef lagoon. It’s one of my favourite places to pause and admire the scenery, when I’m out on my swim.

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In Environmental degradation Tags corals, coral reef, Norfolk Island, White syndrome, coral disease
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A bubble-tip anemone, Norfolk Island

Do sea anemones hold the key to immortality?

October 17, 2023

A close relative of corals and jellyfish, sea anemones are soft-bodied animals that ensnare passing prey with their stinging tentacles. No one really knows how long they can live, but in the wild they are thought to live for more than a hundred years. They have some clever adaptations that contribute to their longevity. Maybe they can teach us their secrets for a long life!

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Tags Sea anemone, Norfolk Island, marine invertabrates, immortality, telomeres
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Older Posts →
Featured
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
A coral reef out of balance
Nov 8, 2025
A coral reef out of balance
Nov 8, 2025

After the long dry spell, the lagoon was crystal clear and full of life. But with the return of the rains, something else has returned too – the brown, filamentous mats of Lyngbya. It’s not seaweed, it’s a cyanobacterium, and when it takes hold it smothers coral and rubble alike. The reef’s way of showing us that every drop of water, from tank to tide, is connected.

Nov 8, 2025
Aglow among the spines
Oct 25, 2025
Aglow among the spines
Oct 25, 2025

Ever seen a sea urchin that seems to glow blue from the shadows? That’s Diadema savignyi showing off its reef shimmer. Beautiful, a little spiky, and definitely not to be messed with.

Oct 25, 2025
The funky seventies sea slug – Halgerda willeyi
Oct 15, 2025
The funky seventies sea slug – Halgerda willeyi
Oct 15, 2025

If ever a sea slug was channeling the 1970s, it’s Halgerda willeyi. With its groovy orange lines and chocolate-brown bumps, it looks straight out of a vintage lounge suite – the kind with shag pile carpet and bold floral cushions. Proof that nature was nailing retro design long before humans caught on.

Oct 15, 2025
Haddon's barometer
Oct 5, 2025
Haddon's barometer
Oct 5, 2025

This Haddon’s anemone has been quietly living in the middle of Norfolk Island’s Emily Bay for years, bleaching and recovering with the seasons. Like corals, sea anemones host microscopic algae that provide most of their food. When stressed by heat or rainfall changes, they lose colour – and tell a story about seasonal changes to the weather.

Oct 5, 2025
Honoured to be featured
Sep 30, 2025
Honoured to be featured
Sep 30, 2025

I left school in the UK nearly 50 years ago, so it was a pleasant surprise to be invited to share some images and take part in an interview for an article about my work, to be published in the annual glossy magazine the school now produces. Here is the end product.

Sep 30, 2025
Celebrating Biodiversity Month on Norfolk Island
Sep 7, 2025
Celebrating Biodiversity Month on Norfolk Island
Sep 7, 2025

September is Biodiversity Month – the perfect time to celebrate the astonishing variety of life on Norfolk Island’s reef. From new fish sightings to coral mosaics, every observation is a reminder of how much there is still to learn and protect.

Read more about why biodiversity matters, globally and right here in our lagoon.

Sep 7, 2025
The fate of a coral colony when it succumbs to white syndrome – four years on
Aug 24, 2025
The fate of a coral colony when it succumbs to white syndrome – four years on
Aug 24, 2025

I’ve tracked one plating Acropora coral from 2021 to 2025. In just a few weeks, white syndrome wiped it out. Nearly four years years on, it’s still smothered in algae and sea squirts, with only the tiniest hint of new growth. It’s a stark reminder: without tackling the root cause, we’re just watching the same sad story repeat itself.

Aug 24, 2025

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