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Norfolk Island's Reef

Discover a fragile paradise – Norfolk Island's beaches, lagoons and coral reef
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    • Algae
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    • Eels
    • Everything Else
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    • Out On A Swim Index
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  • Out on a swim - blog
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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.

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This is what good fish habitat looks like – plenty of structure, plenty of shelter, plenty of places to feed, and plenty of fish making use of it.

Pulling the rugosity from out of the reef

October 10, 2026

What do ‘rugosity’, structural complexity and channeling your inner fish have in common? Quite a lot, as it turns out. This week I’m looking at how all the lumps, bumps, branches, holes and ledges on a reef create habitat – with a brief detour into one of my long-standing tricks for navigating tertiary study: write down the jargon until it starts to make sense.

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In Fish Tags Rugosity, Structural complexity, corals, coral reef, habitat
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An aatuti guarding his eggs, Norfolk Island

From coral scar to aatuti farm

June 20, 2026

Aatuti are bold little algae farmers, but how does one of their farms begin? Over the past year, I have been following several coral patches as small white scars became algal footholds, then larger defended patches. I still cannot say what caused the first wounds, but the photo sequences show something fascinating: on a reef where algae is already gaining ground, even tiny changes on the coral surface can become part of a much bigger story.

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In Fish Tags Fish behaviour, Fish, aatuti, Parma polylepsis, banded scalyfin, algae, Algae farms
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Bluespine unicornfish, Naso unicornis. Note the two scalpels at the base of its tail. These fish have been found to live to at least 50 years old. Norfolk Island

How surgeonfishes got their name

June 14, 2026

Surgeonfish are named for the sharp little scalpels near their tails, but on Norfolk’s reef their more useful work happens at the other end. Pencil surgeonfish, bluespine unicornfish and their relatives help browse algae across the reef – a small daily job that becomes very valuable on an algae-rich lagoon reef like ours.

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In Fish, Fish species Tags surgeonfish, Bluespine unicornfish, convict surgeonfish, pencil surgeonfish, Fish, Norfolk Island, reef fish
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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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Bluebarred Parrotfish – Scarus ghobban, first recorded in Norfolk Island’s lagoons in February 2021

Biodiversity matters

July 14, 2025

Over five and a half years of snorkelling Norfolk’s lagoon, we’ve documented 23 fish species not previously recorded in this area. Some are local ghosts, others climate migrants. These observations help us understand and protect what makes our reef so special.

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In Fish Tags Fish, fish species, biodiversity
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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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Echidna nebulosa, snowflake moray, Norfolk Island

A smooth and slippery echidna

December 10, 2024

How did the snowflake moray get its proper (scientific) name Echidna nebulosa, and what does it have to do with Australia’s famous and iconic marsupial, the echidna? Read on to find out more …

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In Fish, Fish species Tags Moray, Eel, Fish, Taxonomy, Echidna
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Green moon wrasse, Norfolk Island, 17 July 2024

Ageing colourfully. This guy!

July 23, 2024

I’ve been photographing this guy, a green moon wrasse, since 2020, when he was a young adult just transitioning from being a female to a male. Green moon wrasse are said to live five to seven years in the wild, which means that our lovely old friend here could well be classified as an elder. This post is dedicated to this cheeky and inquisitive fish, the boss!

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In Fish Tags Fish behaviour, Fish, fish species, wrasse, green moon wrasse
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Male birdnose wrasse, Gomphosus varius, Norfolk Island

Gender transitioning in the birdnose wrasse

July 7, 2024

All birdnose wrasses are born female but will change to males if the conditions are right. Its appearance changes radically throughout is lifecycle, from when it is a juvenile, through to being a female and then finally to being a male (known as sexual metamorphosis, or sequential hermaphroditism). For about three weeks you can see that transition taking place in the sequence of photos in this blog.

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In Fish Tags Fish, Fish behaviour, fish species, wrasse, bird wrasse
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Blue-barred parrotfish (Scarus ghobban), last seen in September 2021

Fish stocktake – the mysteries, the surprises and the wins

April 22, 2024

In my ‘Year in review for 2023 on Norfolk Island’s reef’, published in December 2023, I made a few observations about the apparent disappearance of some fish species from Norfolk Island’s lagoons. I thought I would revisit these, principally because since December there has been so much additional fish activity here, with some exciting population increases and a few new species turning up.

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In Biodiversity, Fish, Fish species Tags Fish behaviour, Fish, weather, rainfall, fish species, observations
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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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Featured
When algae move in – the changing reef neighbourhood
November 1, 2026
When algae move in – the changing reef neighbourhood
November 1, 2026

Algae are a natural part of Norfolk Island's reef, changing with the underwater seasons. But sometimes their beautiful green growth conceals a rather sad story. In the fifth article of my six-part photographic series, I revisit familiar places to see how algae have changed over the years – and what might be hiding underneath.

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November 1, 2026
The slow disappearance – disease on the reef
October 30, 2026
The slow disappearance – disease on the reef
October 30, 2026

What happens after coral disease has run its course? In the fourth article of my six-part photographic series, I revisit colonies I've watched lose living tissue, sometimes alarmingly quickly. From a potentially century-old brain coral that lost most of its living tissue in less than 100 days to the algae-covered skeletons left years later, these photographs reveal the longer-term consequences of coral disease on Norfolk Island's reef.

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October 30, 2026
When storms rearrange the reef
October 28, 2026
When storms rearrange the reef
October 28, 2026

Sometimes the sea rearranges a reef in a matter of hours! In the third article of my six-part photographic series, I revisit corals broken, overturned or swept away by powerful swells and storm surges. Some disappeared altogether, while others found surprising ways to survive. Five photographic sequences reveal just how dramatically Norfolk Island's reef can change.

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October 28, 2026
When the reef fights back – coral growth and recovery
October 26, 2026
When the reef fights back – coral growth and recovery
October 26, 2026

Not every coral story ends badly! Among six years of underwater photographs are some wonderful examples of growth, survival and recovery. From corals that have grown spectacularly to others that have survived bleaching, breakage or even being turned upside down, this second article in my photographic series celebrates some of the reef's more encouraging stories.

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October 26, 2026
The neighbours – six years of watching the same reef
October 24, 2026
The neighbours – six years of watching the same reef
October 24, 2026

When I began photographing Norfolk Island's reef in 2020, I simply recorded whatever caught my eye. Six years later, those photographs have become a record of individual corals and their changing fortunes – growth, competition, survival and loss. This is the first of six articles looking back at what I've seen, and sometimes what I wish I hadn't.

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October 24, 2026
Pulling the rugosity from out of the reef
October 10, 2026
Pulling the rugosity from out of the reef
October 10, 2026

What do ‘rugosity’, structural complexity and channeling your inner fish have in common? Quite a lot, as it turns out. This week I’m looking at how all the lumps, bumps, branches, holes and ledges on a reef create habitat – with a brief detour into one of my long-standing tricks for navigating tertiary study: write down the jargon until it starts to make sense.

Read more →
October 10, 2026
How does a sea slug smell?
September 27, 2026
How does a sea slug smell?
September 27, 2026

It started with a close-up of a little Elysia and two rhinophores that looked like tiny rolled-up scrolls. Once I noticed them, I started going back through years of sea-slug photos and realised just how wildly different these sensory organs can be – ridged, rolled, curled, tubular and, in sea hares, distinctly rabbit-eared. So this week’s rabbit hole is all about how sea slugs ‘smell’ underwater, and why their noses come in so many different shapes.

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September 27, 2026
The Elite Fleet sails in
September 19, 2026
The Elite Fleet sails in
September 19, 2026

Nearly six years ago, my very first blog post was about the strange blue and violet creatures that live at the ocean’s surface – a group I christened Norfolk Island’s ‘Elite Fleet’. Since then I’ve seen plenty of bluebottles and the occasional violet sea snail, but never a by-the-wind sailor. Until this morning. Velella velella is not a true jellyfish, but a colonial hydrozoan with a transparent sail that lets the wind help carry it across the ocean. So what exactly is this extraordinary little creature, how does it ‘sail’, and what connects it to the rest of the fleet?

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September 19, 2026
In a nutshell – where I stand on the proposed Norfolk Island Marine Park
September 18, 2026
In a nutshell – where I stand on the proposed Norfolk Island Marine Park
September 18, 2026

I support the proposed expansion of Norfolk Marine Park and its renaming as Norfolk Island Marine Park. There is much to welcome – strong offshore protection, no mining, and recognition of the importance of sustainable local fishing. But I also have some reservations. Why does Cascade need to be removed from the Marine Park at all? How will more than 430,000 km² actually be monitored and enforced? How do we make sure Norfolk people have a genuine role in management? And, above all, how do we ensure that the enormous new park does not draw attention away from the small, stressed reef immediately beside us?

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September 18, 2026
No seagrass, but plenty of turtles
September 13, 2026
No seagrass, but plenty of turtles
September 13, 2026

Norfolk Island does not have seagrass, although one of our most conspicuous green algae is often mistaken for it. Feather and grape Caulerpa can both form striking patches across the lagoon. I take a closer look at what Caulerpa actually is, why it is so easily confused with seagrass, and where our green turtles fit into the story.

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September 13, 2026

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