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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.

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
Comment

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
2 Comments

Threadfin butterflyfish, Chaetodon auriga, Norfolk Island

Butterfly, flutterbyfish

March 17, 2023

Butterflyfish are flighty, brightly coloured and beautifully conspicuous on our coral reef in their bright yellows and oranges, white and black livery. On Norfolk Island we regularly see fourteen species, just a small portion of the more than 100 species, globally. Large numbers of butterflyfish are a good sign of a healthy reef.

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In Fish species Tags butterflyfish, Fish, fish species, biodiversity, coral reef
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Yellowstripe goatfish, Mulloidichthys flavolineatus

By the hair of a goatfish's chinny chin chin!

March 16, 2023

If you go for a snorkel on Norfolk Island’s reef, one family of fish that you are bound to see is members of the goatfish family. I have seen have six different species inside our lagoons. You can see them all here.

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In Fish species Tags goatfish, Fish, fish species
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Adult female elegant wrasse, Norfolk Island

Ageing elegantly – the elegant wrasse's lifecycle

March 15, 2023

It’s always fascinating to see how fish change in appearance as they mature. Today’s blog post features the elegant wrasse, Anampses elegans. But not only do they change how they look, they also change how they socialise and move about the reef.

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In Fish species Tags fish species, Fish, Elegant wrasse
1 Comment

Norfolk Island blenny, Parablennius serratolineatus

Norfolk Island's endemics on record

March 14, 2023

It is fascinating to me that, in terms of biodiversity, there is still a slight feel of the frontier to Norfolk Island. So remote and isolated from any other land mass, it stands to reason that we have some different species that are found only here. On such is the Norfolk Island blenny.

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In Biodiversity Tags fish species, Fish, endemic, Norfolk Island, Norfolk Island blenny
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A bluestreak cleaner wrasse (Labroides dimidiatus) cleaning a coral sea gregory (Stegastes gascoynei)

One small fish for one big job

March 13, 2023

Bluestreak cleaner wrasse, Labroides dimidiatus, are important critters on our coral reefs. These fish offer a swim-through full-body maintenance shop for other fish species – their clients – nibbling away dead skin and any nasty ectoparasites that might be living on their clients. There’s a lot to be learned about a reef from watching these busy little fish.

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In Fish species Tags Bluestreak cleaner wrasse, cleaning stations, Fish, reef fish, fish species, parasites, Fish behaviour
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Low tide at Cemetery Bay, Norfolk Island

A rare gem – Cemetery Bay, Norfolk Island

March 12, 2023

No focus on Norfolk Island’s reef would be complete without a look at Cemetery Bay. It’s worth strolling along this beautiful beach at low tide. It is the island’s dog beach, so you will see plenty of locals out walking here, but better still is what you can see in the water – healthy corals happily growing right up to the beach.

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In Corals Tags Cemetery Bay, corals, Coral, coral reef, rockpools
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Featured
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
A coral reef out of balance
Nov 8, 2025
A coral reef out of balance
Nov 8, 2025

After the long dry spell, the lagoon was crystal clear and full of life. But with the return of the rains, something else has returned too – the brown, filamentous mats of Lyngbya. It’s not seaweed, it’s a cyanobacterium, and when it takes hold it smothers coral and rubble alike. The reef’s way of showing us that every drop of water, from tank to tide, is connected.

Nov 8, 2025
Aglow among the spines
Oct 25, 2025
Aglow among the spines
Oct 25, 2025

Ever seen a sea urchin that seems to glow blue from the shadows? That’s Diadema savignyi showing off its reef shimmer. Beautiful, a little spiky, and definitely not to be messed with.

Oct 25, 2025
The funky seventies sea slug – Halgerda willeyi
Oct 15, 2025
The funky seventies sea slug – Halgerda willeyi
Oct 15, 2025

If ever a sea slug was channeling the 1970s, it’s Halgerda willeyi. With its groovy orange lines and chocolate-brown bumps, it looks straight out of a vintage lounge suite – the kind with shag pile carpet and bold floral cushions. Proof that nature was nailing retro design long before humans caught on.

Oct 15, 2025
Haddon's barometer
Oct 5, 2025
Haddon's barometer
Oct 5, 2025

This Haddon’s anemone has been quietly living in the middle of Norfolk Island’s Emily Bay for years, bleaching and recovering with the seasons. Like corals, sea anemones host microscopic algae that provide most of their food. When stressed by heat or rainfall changes, they lose colour – and tell a story about seasonal changes to the weather.

Oct 5, 2025
Honoured to be featured
Sep 30, 2025
Honoured to be featured
Sep 30, 2025

I left school in the UK nearly 50 years ago, so it was a pleasant surprise to be invited to share some images and take part in an interview for an article about my work, to be published in the annual glossy magazine the school now produces. Here is the end product.

Sep 30, 2025

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