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Norfolk Island's Reef

Discover a fragile paradise – Norfolk Island's beaches, lagoons and coral reef
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    • Eels
    • 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.

Convict snake eel - Leiuranus versicolor

Banded, convict and spotted snake eels - know the difference

August 31, 2021

The last day of winter, but here on the island spring is already with us. The bees are furiously busy with the clover in our paddock and the lavender hedge, while the tips of the frangipani trees are pushing out new leaves.

Glorious sunshine and winds from the southwest for a couple of days this week meant I was battling against it while swimming at the weekend!

A beautiful banded snake eel, Leiuranus semicinctus, popped into view on Saturday (top image). I haven’t seen any of these, apart from one dead one a few weeks ago, over winter, so it was wonderful to see this handsome fellow the other day.

Banded snake eel - Leiuranus semicinctus

I often get asked if these are sea snakes and if they are dangerous. They are in fact, as their name suggests, eels, and I find them to be very docile and will generally swim away or dive incredibly fast into the sand when approached too closely.

We have a few different snake eels: spotted, banded and convict. I’ve included photos of all three here so you can see the difference. It has been suggested to me that we may have a couple of different subspecies of these – which are, as yet, undescribed – because a couple look a little different. This isn’t something I know much about, but it would be exciting beyond belief if we did have some unique ones here.

Below are images of the three different types of snake eels found in Norfolk Island’s lagoons.

View fullsize Ocellate snake eel - Myrichthys maculosus
Ocellate snake eel - Myrichthys maculosus
View fullsize Ocellate snake eel - Myrichthys maculosus
Ocellate snake eel - Myrichthys maculosus
View fullsize Ocellate snake eel - Myrichthys maculosus
Ocellate snake eel - Myrichthys maculosus
View fullsize Banded snake eel - Leiuranus semicinctus
Banded snake eel - Leiuranus semicinctus
View fullsize Banded snake eel - Leiuranus semicinctus
Banded snake eel - Leiuranus semicinctus
View fullsize Banded snake eel - Leiuranus semicinctus
Banded snake eel - Leiuranus semicinctus
View fullsize Convict snake eel - Leiuranus versicolor
Convict snake eel - Leiuranus versicolor
View fullsize Convict snake eel - Leiuranus versicolor
Convict snake eel - Leiuranus versicolor
View fullsize Convict snake eel - Leiuranus versicolor
Convict snake eel - Leiuranus versicolor
View fullsize Convict snake eel - Leiuranus versicolor
Convict snake eel - Leiuranus versicolor
View fullsize Convict snake eel - Leiuranus versicolor
Convict snake eel - Leiuranus versicolor
View fullsize Convict snake eel - Leiuranus versicolor
Convict snake eel - Leiuranus versicolor

A convict snake eel, Norfolk Island

One thing I love to watch is the bluestreak cleaner wrasse, Labroides dimidiatus, hard at work. You often see fish queueing up for a once-over from this little guy. This morning it looked like they were all getting in early for a spring clean! I’ve included a few photos of this busy beaver cleaning some yellowstripe goatfish, Mulloidichthys flavolineatus (left) and a Coral Sea gregory, Stegastes gascoynei (right).

View fullsize Bluestreak cleaner wrasse with goatfish
Bluestreak cleaner wrasse with goatfish
View fullsize Bluestreak cleaner wrasse with a Coral Sea gregory
Bluestreak cleaner wrasse with a Coral Sea gregory
Tags Snake eel, banded snake eel, Convict snake eel, Spotted snake eel, Norfolk cardinalfish, Emily Bay, cleaner wrasse
← Report released into the health of Norfolk Island's reefWhen corals go blue! →
Featured
Biomimicry: How a Boxfish Caught Mercedes Benz’s Eye
Aug 10, 2025
Biomimicry: How a Boxfish Caught Mercedes Benz’s Eye
Aug 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.

Aug 10, 2025
Patchwork Corals: How Colonies Fuse to Form Living Mosaics
Aug 3, 2025
Patchwork Corals: How Colonies Fuse to Form Living Mosaics
Aug 3, 2025

Some corals wear more than one colour for a reason. When Paragoniastrea australensis colonies fuse early in life, they form living mosaics. A beautiful reminder of coral cooperation on Norfolk Island’s reef.

Aug 3, 2025
Reef relief
Jul 28, 2025
Reef relief
Jul 28, 2025

Today, 28 July, is World Nature Conservation Day. After the dry 2024, Norfolk Island’s reef is looking healthier – a brief reprieve as less water - laden with nutrients - flowed into the lagoon. These photos show what’s possible. It’s a reminder that recovery is within reach – though renewed runoff could quickly undo the gains.

Jul 28, 2025
Emily Bay's big 'brain' coral
Jul 20, 2025
Emily Bay's big 'brain' coral
Jul 20, 2025

In Emily Bay, Norfolk Island, a single coral bommie – Paragoniastrea australensis – has stood for decades as a micro-reef, harbouring diverse marine life and local memories. Once photographed in 1988 and still thriving today, it remains a keystone of reef biodiversity and a living link between past and present.

Jul 20, 2025
Biodiversity matters
Jul 14, 2025
Biodiversity matters
Jul 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.

Jul 14, 2025
Poop power
Jun 17, 2025
Poop power
Jun 17, 2025

Not all poop on a reef is bad poop. In fact some kinds of poop can be a reef’s most important invisible engine. Fish poop, bird poop – even poop that gets eaten again by other fish – all of it keeps the ecosystem ticking over in a way that’s nothing short of extraordinary.

Jun 17, 2025
Glimpses of recovery: what the reef could be if we let it
Jun 13, 2025
Glimpses of recovery: what the reef could be if we let it
Jun 13, 2025

Day 6 of this photo series from Norfolk Island coincides with the final day of the UN Ocean Conference in Nice. After a week of documenting decline, today’s post offers a different view – what reef recovery can look like when conditions improve. Drought in 2024 gave the reef a break, and the results were unmistakable: healthier corals, lower disease, and more fish. This is what’s possible if we act.

Jun 13, 2025
Warning signs: quiet and unnoticed collapse of two coral colonies
Jun 12, 2025
Warning signs: quiet and unnoticed collapse of two coral colonies
Jun 12, 2025

Day 5 of my blog series for the UN Ocean Conference: two long-lived coral colonies in Norfolk’s lagoon died quietly from disease. No drama – just slow collapse and overgrowth by algae. A reminder that not all reef losses are loud, but they are happening.

Jun 12, 2025
Warning signs:  what Norfolk Island’s reef is telling us
Jun 11, 2025
Warning signs: what Norfolk Island’s reef is telling us
Jun 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.

Jun 11, 2025
Warning signs: coral disease takes hold
Jun 10, 2025
Warning signs: coral disease takes hold
Jun 10, 2025

In Day 3 of this blog post series, published while leaders gather at the UN Ocean Conference in Nice, we see Norfolk Island’s coral reef lagoon quietly delivering a stark warning: recurrent land-based pollution, coral disease, and delayed decisions are dismantling this ecosystem in real time.

Jun 10, 2025

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