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Norfolk Island's Reef

Discover a fragile paradise – Norfolk Island's beaches, lagoons and coral reef
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    • Kingston, Norfolk Island
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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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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
What Norfolk Island’s reef tells us about environmental blind spots
Apr 5, 2026
What Norfolk Island’s reef tells us about environmental blind spots
Apr 5, 2026

The Kingston dredging proposal on Norfolk Island raises a bigger question than dredging alone: how well do standard environmental assessment tools capture the real significance of a remote and unusual reef system like Norfolk Island’s?

Apr 5, 2026
Hammer coral time!
Mar 30, 2026
Hammer coral time!
Mar 30, 2026

Hammer corals have unique tentacles that are large, fleshy, and tubular; these terminate in a ‘T’-shaped, hammer-head or anchor. Beneath all these softly waving tentacles is an extraordinary skeleton structure, which helps define them as a large polyp stony coral.

Mar 30, 2026
Norfolk Island’s fishes: drifters, residents and the ones still missing
Mar 24, 2026
Norfolk Island’s fishes: drifters, residents and the ones still missing
Mar 24, 2026

Norfolk Island’s fish fauna reflects both connection and isolation. Some species may arrive from elsewhere as drifting larvae, some populations appear to persist locally, and some fishes known from islands on either side of Norfolk have still not been recorded here. This post looks at what old survey work, regional checklists and genetic studies suggest about that more complicated picture.

Mar 24, 2026
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

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