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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.

The surf breaking over Norfolk Island’s reef, Slaughter Bay

The Water Rats – the Southern Hemisphere's oldest surf lifesaving club?

November 19, 2023

Can Norfolk Island claim the Southern Hemisphere’s oldest surf lifesaving club? Read on to find out more!

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In History Tags surf, Kingston, World Heritage Area, Convicts
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The marine algae Hydroclathrus clathratus, Norfolk Island

Sponge blob!

October 29, 2023

It’s common, wide spread around the globe, and yet I have only noticed it in recent weeks. It has been hiding in plain sight, yet this spongey algal blob, Hydroclathrus clathratus, is edible, and has been found to possess some remarkable medicinal properties. Read on to find out more!

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In Algae Tags algae, Hydroclathrus clathratus, Medicine, research, anti-viral, edible algae, seaweed
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A bubble-tip anemone, Norfolk Island

Do sea anemones hold the key to immortality?

October 17, 2023

A close relative of corals and jellyfish, sea anemones are soft-bodied animals that ensnare passing prey with their stinging tentacles. No one really knows how long they can live, but in the wild they are thought to live for more than a hundred years. They have some clever adaptations that contribute to their longevity. Maybe they can teach us their secrets for a long life!

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Tags Sea anemone, Norfolk Island, marine invertabrates, immortality, telomeres
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Acropora corals, Norfolk Island’s reef

Brown? Yes. Boring? Definitely not!

October 11, 2023

Norfolk Island’s reef is one of Australia’s most southerly. It isn’t showy like the Great Barrier Reef, and I often hear the comment that it is a little dowdy – boring and brown. I’m here to tell you that it is anything but.

For this little photo essay I randomly selected just a handful of my many ‘boring, brown’ coral images to demonstrate my point. I barely scratched the surface of my photo library, yet I think you will agree, the diversity is just amazing!

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In Corals Tags corals, Norfolk Island, coral reef, Great Barrier Reef, Coral, biodiversity
1 Comment

A Norfolk Island endemic species, the Norfolk Island blenny, Parablennius serratolineatus

Atlas of Living Australia recognises iNaturalist observations for Norfolk Island

August 16, 2023

After about 18 months of asking, and with the help of some wonderful people from the data department of the Atlas of Living Australia and the Australian Museum, the Atlas of Living Australia website now recognises iNaturalist citizen science observations for Norfolk Island. Which is definitely something worth celebrating!

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In Biodiversity Tags Citizen science, iNaturalist, observations, Atlas of Living Australia, Australian Museum, biodiversity, endemic species, Environment, environmental protections, Environmental protection
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Old Military Barracks after heavy rain, November 2020

The clock is ticking for Norfolk Island’s reef

August 1, 2023

Three years ago, on 31 July 2020, we woke after a night of torrential rain to a scene of devastation in Emily Bay on Norfolk Island. Arguably one of the most beautiful bays in the world was a fetid, smelly mess caused by the raw sewage that had flowed from the poorly maintained sewerage works and private septic tanks, down the hill and into the bay. Read on to find out what has happened since that dreadful day.

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3 Comments

Emily Bay, full moon rising, by Norfolk Island photographer Joelene Oliver

Full moon, low tides and Norfolk Island’s reef

June 2, 2023

With the low, low tides associated with a full moon, the bays on Norfolk Island are like a huge, calm swimming pool, giving us some great snorkelling opportunities. These low tides should also let us view the causeway, which will no doubt be exposed too. This post explores these opportunities as well as what the low tides mean for corals. Read more in this fact packed blog post.

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In Corals Tags Norfolk Island, Full moon, Low tide, HMS Sirius, causeway, Emily Bay, Slaughter Bay, coral reef, corals, plastic, plastic pollution
2 Comments

A small school of scissortail sergeants with one interloper, an Indo-Pacific sergeant, Norfolk Island

Same, same, but different – confusing fish identities

May 25, 2023

There are a few fish species in Norfolk Island’s bays that are easily mixed up. Here’s four commonly confused pairs, with a few pointers to help you identify them.

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In Fish species Tags Fish, fish species, coral reef
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Purple velvet sea star, Leiaster leachii, as it broadcasts spawn into the water column, Norfolk Island

Casting your offspring to the currents – sea star reproduction

May 8, 2023

In May on Norfolk Island, the day after the full moon and at low tide, I witnessed an enormous Leach’s sea star, Leiaster leachi, as it broadcast its gametes into the water column. What an amazing WOW moment! And what a privilege to witness such a rare event. Here are some images and video of the action.

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In Sea stars Tags sea stars, starfish, reproduction, spawning, Leach's sea star
2 Comments

Close-up of the underside of the acropora coral colony after being toppled in a storm

The resilience of corals

May 6, 2023

On Norfolk Island’s reef, acropora coral colonies upturned in storm surges in September 2020 initially struggled to survive, but now they are now showing signs of new, healthy growth. This incredible photo is of those early days as it struggled. You can read more and see what it looks like today in my latest blog post, here.

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Crustose coralline algae, Norfolk Island

Pretty in pink – the real coral reef builders

April 8, 2023

Animal, vegetable or mineral? What are crustose coralline algae? Are they important? What role do they play on our coral reefs?

There’s a lot to learn about coralline algae. For a humble lifeform, they really pack a punch.

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In Ecosystem Tags algae, coralline algae, crustose coralline algae, coral reef, corals, sea urchin, coral recruitment
1 Comment

My grandson

For the sake of our grandchildren

March 26, 2023

What will my grandson see when he is old enough to snorkel on Norfolk Island’s reef? Will there be anything left as I know it? Or will he think it is all great because of that hoary old phenomenon called ‘shifting baseline syndrome’? This record of all my photos and observations will give him some idea of what we had in our bays in the 2020s.

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In Environmental degradation, Fish species Tags Environment, Environmental protection, water quality, biodiversity, grandchildren, Norfolk Island, Emily Bay
4 Comments

Black Blenny, Enchelyurus ater found in Slaughter Bay, Norfolk Island

Black Blenny - a new record for Norfolk Island

March 25, 2023

This is a copy of the Australian Fishes journal post about new fish sightings on Norfolk Island: ‘This observation [of a black blenny] highlights the power of citizen scientists working with professional ichthyologists to achieve important outcomes,’ Mark McGrouther, Senior Fellow at the Australian Museum.

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In Fish species Tags black blenny, fish species, Fish, new species, Australasian Fishes project, Australian Museum
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Doris, a week after she was taken into rehab

Doris – just one turtle?

March 24, 2023

Many of the turtles that live in Norfolk Island’s coral-reef lagoons are juveniles. In other words, they are the future of their species, and an important piece in the genetic jigsaw. Yet they seem to fall through the cracks when it comes to being protected by the EPBC Act.

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In Environmental degradation Tags Operation Doris, Turtle rescue, Green sea turtle, water quality, EPBC Act
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One of the pair of ‘sometimes’ resident snubnose darts, Norfolk Island

A pair and a spare – snubnose darts on Norfolk Island's reef

March 23, 2023

Norfolk Island’s reef is small and intimate. We can count the numbers of some species of fish on one hand, and that is how I can watch the comings and goings with interest as I swim among them. I love the stories that play out and which I get to witness – these snubnose darts (Trachinotus blochii) are a case in point.

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In Fish species Tags Snubnose dart, fish, fish species, fish behaviour
3 Comments

A sea mat on the edge of the reef where the waves break, Norfolk Island

A tale of two corals

March 22, 2023

My March focus on Norfolk Island’s reef could almost go on for a full year, there’s so much to write about. But time dictates, so I will confine my efforts to one concentrated effort of randomness! Randomness, because there has been no plan to my posts. They have evolved as the month has progressed. Today I highlight two very different corals commonly seen, but not necessarily common.

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In Corals Tags corals, coral reef, soft coral, hard coral, water quality, biodiversity, IUCN Red List, Vulnerable
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Bubbles of oxygen forming on algae, photobombed by a tiny sea slug, sp, Elysia

Bubble and fizz – a quick guide to coral reef chemistry

March 21, 2023

March is often the warmest month on Norfolk Island’s reef, so it's no surprise that the algae are very busily photosynthesising and flourishing. Yesterday, I noticed that the algae had created a thick carpet of bubbles. As I swam my face was gently brushed by thousands of tingling bubbles, fizzing to the surface. It was quite a sight. And a rather weird sensation. So what is going on here?

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In Environmental degradation Tags Algae, coral reef, corals, photosynthesis, reef chemistry, water quality
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Emily Bay, Norfolk Island, #thecoloursarereal!

Beneath the waves in Emily Bay, Norfolk Island

March 20, 2023

Looking across Emily Bay, do you wonder what is beneath the waves in there? Although this is not strictly part of Norfolk Island’s reef, it is part of one continuous ecosystem; therefore, in today’s March focus on Norfolk Island’s reef I thought it was worth showing you what you can see at your feet as you wade into the shallows.

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In Ecosystem Tags Emily Bay, Snorkelling, Fish, fish species, ecosystem
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Stunning Emily Bay, Norfolk Island.

Tiptoeing through the government silos

March 19, 2023

In the 1960s we had reports voicing concerns around water quality, but nothing was done. When the Commonwealth of Australia’s EPBC Act came into force in 1999, nothing was done. Surely it is high time the issues of failing and inadequate infrastructure, deficient Norfolk Island laws and unsatisfactory protections were fixed once and for all?

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In Environmental degradation Tags Environment, Environmental protection, government, government policy, environmental protections, water quality, sewerage, coral reef, endemic, threatened species, biodiversity
2 Comments

Acropora coral overgrown with algae, Norfolk Island

We can't say we weren't warned

March 18, 2023

Today’s post for the March focus on Norfolk Island’s reef is a letter. Just that, and nothing more. The authors of this letter have very generously given me permission to reproduce it here. In it, Dr Kellie Pendoley and Dr Martin Goldsmith warn us about the future of Emily Bay. Written nearly eight years ago they give the coral reef habitat five to ten years before it is gone as we know it.

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In Environmental degradation Tags Environment, coral reef, corals, Environmental protection
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Featured
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
Nature is my teacher
Dec 3, 2025
Nature is my teacher
Dec 3, 2025

This is a thank-you note. Five years after my first Out on a swim post – written with zero marine science quals and a head full of questions – I’m still in the water, now as a PhD candidate, because an extraordinary mix of locals, volunteers, researchers and public servants decided to share what they knew. This is the story of how nature – and a very patient community – became my teachers.

Dec 3, 2025
Reef grief: what dredging has done to other reefs
Nov 30, 2025
Reef grief: what dredging has done to other reefs
Nov 30, 2025

From Miami to Fiji, from Dubai to tiny village harbours on atolls, dredging near coral reefs has left a long trail of scars – even on ‘small’ projects. This follow-up to last week’s Kingston post walks through real examples of what happened elsewhere, and what that should make us think about before we dig up our own reef.

Nov 30, 2025
To dredge or not to dredge? The Kingston Pier channel project
Nov 20, 2025
To dredge or not to dredge? The Kingston Pier channel project
Nov 20, 2025

How much risk are we really taking with the planned dredging at Kingston Pier – and how much protection do our corals actually have on paper? This piece walks through what the federal approval does and doesn’t guarantee, explains why sediment and light matter so much to the reef, and asks the hard questions we need answered before we trade a deeper channel for a shallower future.

Nov 20, 2025

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