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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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A peacock damselfish – Pomacentrus pavo

The curious case of the peacock damselfish

March 7, 2023

Day 7 – March focus on Norfolk Island’s reef

Juvenile peacock damselfish, Pomacentrus pavo, February 2021

Today in my March focus on the coral reef of Norfolk Island I am featuring a fish called the peacock damselfish – Pomacentrus pavo. They are a delicate little fish, a gorgeous neon blue with a pale lemon-tipped tail, which only grow to 8.5 or 9 cm. It can be distinguished from similar fish (such as the neon damsel) by the tiny dark ‘ear’ spot near its gill cover.

I’m rather curious about this guy’s life cycle. Our inshore reef – from Emily Bay to Slaughter Bay – is small, so it’s relatively easy to get to know what is in there. Often you can count the fish of a particular species on one hand, and the peacock damselfish is a perfect example of this.

Because I have been only looking at three individuals, it is interesting to notice how their colours change throughout the year (see the images below). Or maybe it is a trick of the light. Certainly, they seem to lighten up from October through to February.

For ages we had just one that I would see regularly hugging a large bommie in Emily, often on the shady side. I never saw any others of his kind, until one day I saw five babies near a small inshore rock, quite some distance from the original bommie. So clearly there must have been a few others around. That was in February 2021. These babies seemed to disperse across the Emily Bay and channel area that runs between the two bays. At first, I could find four of them, then one disappeared and we were left with just three. For the next 18 months or so I would stop by and observe these three individuals, all living quite distant from each other in a solo existence on their respective coral bommies.

I usually find them midway up the side of a reef wall, although when the coral spawns they get a little more daring and will swim happily around just above the reef, presumably snacking on the coral spawn like the other damsel species.

The curious thing is, that almost overnight at the very end of December, all three of these fish disappeared. Did a message get passed across the water column for them to meet up for breeding? And if so, how? Will they come back? Will there be more babies? I always seem to have so many questions and so few answers!

This year, juvenile fish for any of the species in our bays have been hard to find and I have no idea why. Maybe they are later this year? Maybe the influx of freshwater has driven them out beyond the confines of the lagoons. Our last baby peacock damselfishes appeared in mid-February (2021), so I confess that I had expected to see some by now. I’ll keep looking!

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View fullsize 26 Dec 2022 (227)_crop.jpg
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In Fish species Tags Peacock damselfish, Fish behaviour, Fish, fish species
← You don’t always know what you’ve got – ’til it’s goneDraining the swamp →
Featured
How does a sea slug smell?
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In a nutshell – where I stand on the proposed Norfolk Island Marine Park
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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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No seagrass, but plenty of turtles
September 13, 2026
No seagrass, but plenty of turtles
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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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Watching El Niño from Norfolk Island
September 6, 2026
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September 6, 2026

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What the world’s reefs are telling Norfolk Island
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What the world’s reefs are telling Norfolk Island
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Two major new coral reef reports carry a clear message for Norfolk Island: reefs can recover when pressures ease, but the time available for recovery is shrinking. Norfolk Islanders were raising concerns about water quality, runoff and the health of Emily and Slaughter Bays nearly forty years ago. Today we have much better science, a changing climate and a far clearer understanding of how closely the catchment and reef are connected. This article looks at what that means for water quality, long-term monitoring, dredging and how we manage Kingston from land to sea.

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September 2, 2026
When the map changes
August 25, 2026
When the map changes
August 25, 2026

A fish once thought to belong only to Norfolk turns up elsewhere; another appears here hundreds of kilometres beyond its known range. Cardinalfishes and a Sabre squirrelfish show how our maps of species distributions are revised.

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August 25, 2026
Endemic, native, undescribed – what do these words actually mean?
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What’s grazing in the green stuff?
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