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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.

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Tonna melanostoma

Citizen science in action on Norfolk Island

February 28, 2022

My photos of the Tonna melanostoma, a giant underwater mollusc, are the only ones of the live animal in the public domain. We are so fortunate to have these special and rare creatures living in our coral-reef lagoons; their existence here serves to highlight what a special habitat Norfolk Island’s reef really is. It is an ecosystem that must be preserved at all costs.

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Tags Tonna melanostoma, Royal Belgian Society for Conchology, molluscs, tun shell, Emily Bay, Gloria Maris, ecosystem, rare sea snail
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Island Sea Star - Astrostole multispina

Sea stars? Starfish? What’s the difference?

February 7, 2022

Marine scientists have been giving these underwater stars an image makeover. The starfish of our childhoods, for those of you who have a few beachside summers under your beach towel, is now more properly known as a sea star. They have seawater for blood, two stomachs, no brain, and tiny ‘eyes’ at the end of each arm!

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In Sea stars Tags starfish, sea stars, Norfolk Island, ocean, coral reef
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Remnant reef overgrown with algae, 31 January 2022, Emily Bay, Norfolk Island

Come on in. The water's fine ...

January 31, 2022

As Costa Georgiadis says, nature tells the truth, and we must only look at our reef on Norfolk Island to know its truth. We, as custodians, have not been caring enough for it and now that carelessness is coming home to roost.

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In Environmental degradation Tags corals, coral reef, environment, ecosystems, alagae, pollution, Norfolk Island, Coral disease, water quality
2 Comments

The Great Big Coral Spawn Myth

January 18, 2022

The mass spawning coral myth, debunked: coral mass spawning has captured the imagination of the public, while some of the coverage in the media has cemented a number of myths surrounding the event. The most pervasive being that mass spawning only occurs on one night each year. Not true! Read more here.

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In Corals Tags Coral, coral spawning, coral reproduction, Norfolk Island, spawning, coral reef
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Old Gnarly the swal doodle, Emily Bay, Norfolk Island

Old Gnarly, the swal doodle

January 1, 2022

When I’m out on my swim, one guy I always stop by and say hello to is Old Gnarly, a spotted porcupinefish known here as a swal doodle. He knows when I arrive. The first thing you see are his big luminescent white lips as he floats to the door of his cave. We pause, study each other for a moment, then I give him the thumbs up before continuing my swim. It is a precious moment when you connect with a wild animal like this, and it makes my day.

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Tags porcupinefish, puffer fish, Emily Bay, swal doodle
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Pink coral spawn floating on the surface of Emily Bay, Norfolk Island, 28 December 2021

Coral spawning, Norfolk Island 2021

December 29, 2021

Out on a swim on the morning of 27 December 2021, the mood was palpably different. Call me fanciful, but I immediately noticed a frisson of excitement among the fish. Lots of activity and agitation. And all kinds of slightly unusual observations. The annual coral spawning here on Norfolk Island had begun.

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Tags coral spawning, coral reef, coral reproduction, Norfolk Island, corals
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Stylocheilus striatus – commonly called the lined sea hare, blue ring sea hare or furry sea hare

Furry sea hares as eco-warriors

December 12, 2021

Stylocheilus striatus – commonly called the lined sea hare, blue ring sea hare or furry sea hare – have appeared in numbers at one end of the shallows of Emily Bay. These little sea hares are great to have around as they consume the toxic blue-green alga that fish and other herbivores don’t or can’t eat or tolerate.

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Tags sea hares, eco-warriors, ecosystem, algae, nutrients, pollution, water quality, Emily Bay
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#LittleFig, my puppa, following me in for a swim at Cemetery Bay, the island’s dog beach.

Penis fencing flatworms

November 2, 2021

Here’s a quick round up of what has been happening on Norfolk Island’s reef in the last couple of weeks. There is always so much going on. Read on to find out about the mating habits of flatworms, and see a busy bluestreak cleaner wrasse hard at work cleaning his wide variety of customers.

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Tags flatworms, Coral disease, Emily Bay, pollution, cleaner wrasse

Surge wrasse - Thalassoma purpureum

Nuptial colouration in blennies

October 12, 2021

Warmer water and some behavioural changes: some fish are getting their nuptial colours on, while others have started incubating eggs in their mouth. It is all happening ‘out on a swim’. Catch up on the last week in Norfolk Island’s lagoons here.

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Tags nuptual colouration, Blenny, Emily Bay, Raft, pontoon, Southern Eagle Ray, environment, ecosystem, water quality
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Bubble-tip anemone

Turtles and snake eels

September 28, 2021

Emily Bay never fails to lift my spirits. Today in my ‘Out on a Swim’ blog, I talk about our beautiful, elegant snake eels. We have at least three different species. I also saw my elusive spotfin squirrelfish, and our two resident green sea turtles snoozing next to each other. Naawww!

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Tags Green sea turtle, Snake eel, banded snake eel, Convict snake eel
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Full moon rising over our home on Norfolk Island, #DownArthurs

Full moon rising over our home on Norfolk Island, #DownArthurs

September full moon on Norfolk Island

September 21, 2021

The full moon last night brought us some beautiful, settled weather, right on cue, which meant I was able to get out into Slaughter Bay for the first time in ages. Click here to read what was happening in the coral reef lagoons of Norfolk Island.

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Tags Coral disease, corals, coral reef, Lady Musgrave blenny
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Emily Bay in the spring sunshine. The seas outside the lagoons were wild this week.

Emily Bay in the spring sunshine. The seas outside the lagoons were wild this week.

Jockeying for space on the reef

September 14, 2021

I won’t lie, it has been a wipe-out in the bays this week with huge swells and poor visibility. I more than made up for it this morning. Everyone was out and about enjoying the spring sunshine. Apart from the turtle. She was asleep! Read here to find out who else was enjoying the sunshine.

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Tags corals, coral reef, Bluespine unicornfish, Green sea turtle, butterflyfish, bluespotted cornetfish
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A school of sand mullet, Myxus elongatus

Report released into the health of Norfolk Island's reef

September 7, 2021

This week’s observations while out on a swim, included some very active and inquisitive green moon wrasse. One, in particular, followed me for a good half an hour as I made my way around the reef off the Salt House. Find out more about what was happening beneath the waves on Norfolk Island this week.

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Tags sea hares, green moon wrasse, sand mullet, school of fish, Emily Bay, water quality, pollution, Sydney Institute of Marine Science
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Convict snake eel - Leiuranus versicolor

Banded, convict and spotted snake eels - know the difference

August 31, 2021

A beautiful banded snake eel, Leiuranus semicinctus, popped into view on Saturday. These gorgeous guys are docile and will dive head first into the sand if you get too close. Read on to discover how many types of snake eel we have in Norfolk Island’s lagoons.

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Tags Snake eel, banded snake eel, Convict snake eel, Spotted snake eel, Norfolk cardinalfish, Emily Bay, cleaner wrasse
1 Comment

When corals go blue!

August 24, 2021

August is the coldest month of the year in the water here on Norfolk Island, with the temperature hovering around 18–19C. Not only do some swimmers turn a little bit blue if they stay in too long, so too do some of the corals. Read on to find out why.

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Tags butterflyfish, Tracy Ainsworth, Sydney Institute of Marine Science, blue coral, Coral, coral reef
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Snubnose dart

Winter snorkelling on our reef

August 17, 2021

I can guarantee that each time I head out into Norfolk Island’s lagoons I will see something new or interesting. This week was no different. Here is a quick wrap up of some of my more noteworthy observations this week while out on a swim.

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Tags snubnosed dart, Bluespine unicornfish, blacktip morwong, Atagema spongiosa, Green sea turtle, Southern Eagle Ray
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Collector urchin - Tripneustes gratilla

Collector urchin - Tripneustes gratilla

The importance of sea urchins

August 10, 2021

August on Norfolk Island is the coolest month of the year. The southerly winds have been bringing in pounding surf and reduced visibility in the bays. For those who are interested, the water temperature has been hovering between 17C and 18C. This week I showcase some of the different species of sea urchins in our bays and provide a few fast facts about them.

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Tags sea urchin, wunna, sea slugs, environment
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Healthy Acropora, plate coral, in Cemetery Bay

Healthy Acropora, plate coral, in Cemetery Bay

The state of play on Norfolk Island's reef

August 3, 2021

We’ve had more than 55 years of warnings, reports and alarm bells about the water quality entering ‘pristine’ Emily and Slaughter Bays, so we know exactly what is harming our marine ecosystem. Now we just have to fix it.

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The clear water of Emily Bay lagoon on Norfolk Island

Playing the long game: Norfolk Island’s coral reef and lagoons

July 25, 2021

What has taken me down the path from a day job as a writer, editor and communicator to creating a website about Norfolk Island’s coral reef habitat? The story of how and why norfolkislandreef.com.au came into being.

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1 Comment

A platygyra that has dramatically asserted its own space

War of the coral worlds!

July 20, 2021

How do corals assert their space on the reef? Who are the best gardners and protective parents? And have you heard of white syndrome? Sadly we have it on Norfolk Island’s reef. Read more here.

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Tags corals, coral reef, Norfolk Island, coral disease, banded scalyfin, Parma polylepsis, Inscribed wrasse, Notolabrus inscriptus
2 Comments
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Featured
How surgeonfishes got their name
June 14, 2026
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.

June 14, 2026
A shrimp storm
May 28, 2026
A shrimp storm
May 28, 2026

While setting my research cams last week, I swam into what looked like an underwater snowstorm. It appeared to be the aftermath of a mass moulting event, with large numbers of tiny, translucent shrimp-like exoskeletons drifting together near the surface.

May 28, 2026
Kingston dredging: what happens when a reef does not fit the framework
May 28, 2026
Kingston dredging: what happens when a reef does not fit the framework
May 28, 2026

This correspondence with DCCEEW is about more than one dredging proposal. It is about what happens when an ecologically distinctive place is assessed through standard tools that do not always make its most important values easy to see. I am publishing it here because that is something we need to be aware of, both on Norfolk Island and more broadly in Australia.

May 28, 2026
Kingston dredging: the project advances, the questions remain
May 24, 2026
Kingston dredging: the project advances, the questions remain
May 24, 2026

Kingston dredging is edging closer, and the paper trail is growing. This post brings together earlier correspondence with the Department and the latest media release so readers can see what has been asked, what has been answered, and what still remains unclear about the project, its rationale, and the protections proposed for the reef.

May 24, 2026
The lime-green coral in Slaughter Bay – a 40-year paper trail
May 17, 2026
The lime-green coral in Slaughter Bay – a 40-year paper trail
May 17, 2026

Green Mountain – the name I give this coral in my database – is a coral I’ve photographed for years as I swim past. Then I found its backstory in the Norfolk Island National Parks archives: a rough map, reused paper, a note in the margin – ‘still thriving’. That’s how baselines begin.

May 17, 2026
What Norfolk Island’s reef tells us about environmental blind spots
April 5, 2026
What Norfolk Island’s reef tells us about environmental blind spots
April 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?

April 5, 2026
Hammer coral time!
March 30, 2026
Hammer coral time!
March 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.

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

March 24, 2026
18 Jun 2025 (20)_crop.jpg
March 7, 2026
Alveopora or flowerpot coral – how to tell the difference
March 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.

March 7, 2026
Norfolk’s lagoonal reef – the 2025 report, in plain English
February 27, 2026
Norfolk’s lagoonal reef – the 2025 report, in plain English
February 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.

February 27, 2026

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