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Norfolk Island's Reef

Discover a fragile paradise – Norfolk Island's beaches, lagoons and coral reef
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    • Algae
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    • Eels
    • Everything Else
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    • Out On A Swim Index
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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.

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Sabre squirrelfish, Sargocentron spiniferum, seen at Norfolk Island, increasing its known range southwards by 750 km

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.

Read More
In Biodiversity, Fish species Tags Fish, fish species, endemic, native species
Comment

A young Chromis norfolkensis, Norfolk chromis

Endemic, native, undescribed – what do these words actually mean?

August 24, 2026

A Norfolk chromis that turned out not to be Chromis fumea, a blenny found nowhere else, and a tiny goby that may not yet have a name. A look at what we mean by native, endemic, undescribed and newly described – and why scientific names sometimes change.

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In Fish species, Biodiversity Tags Fish, fish species, Norfolk Island, endemic species, native species
Comment

Corals in western Slaughter Bay, close to the Kingston Pier Dredging Project

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.

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In Biodiversity, Ecosystem, Environmental degradation, Corals Tags Environmental protection, corals, coral reef, dredging, Pier, marine environment, marine conservation
Comment

My school’s logo and motto, Christ me spede

Honoured to be featured

September 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.

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In Biodiversity, Ecosystem, Education
Comment

Eclipse butterflyfish – Chaetodon bennetti, Norfolk Island

Celebrating Biodiversity Month on Norfolk Island

September 7, 2025

September is Biodiversity Month – the perfect time to celebrate the astonishing variety of life on Norfolk Island’s reef. From new fish sightings to coral mosaics, every observation is a reminder of how much there is still to learn and protect.

Read more about why biodiversity matters, globally and right here in our lagoon.

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In Biodiversity Tags biodiversity, Fish, corals, Norfolk Island, Emily Bay, Slaughter Bay
Comment

Blue-barred parrotfish (Scarus ghobban), last seen in September 2021

Fish stocktake – the mysteries, the surprises and the wins

April 22, 2024

In my ‘Year in review for 2023 on Norfolk Island’s reef’, published in December 2023, I made a few observations about the apparent disappearance of some fish species from Norfolk Island’s lagoons. I thought I would revisit these, principally because since December there has been so much additional fish activity here, with some exciting population increases and a few new species turning up.

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In Biodiversity, Fish, Fish species Tags Fish behaviour, Fish, weather, rainfall, fish species, observations
Comment

Free weed!

December 22, 2023

I couldn’t resist posting these beautiful images of floating seaweed. Enjoy!

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In Biodiversity, Algae Tags seaweed, algae, Norfolk Island
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
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
Comment

A common view of an aatuti as you swim into its territory!

Phase shifts and biodiversity

March 9, 2023

One species that is doing remarkably well on Norfolk Island’s reef as it inexorably transitions from coral-dominated to algal-dominated is the banded scalyfin, Parma polylepis, which is unsurprising as their main food source is algae. The downside is they harass and bully all the other species that come anywhere near their territory, to the detriment of our biodiversity. Find out more here.

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In Biodiversity Tags banded scalyfin, biodiversity, phase shift, coral reef, algae, water quality
Comment

From front to back: raccoon butterflyfish; blackback butterflyfish; three-striped butterflyfish Back right: Threadfin butterflyfish

No coral? No butterflyfish!

March 4, 2023

Butterflyfish are ‘corallivores’, that is, they feed mainly on coral polyps and the energy-rich mucous that these produce. Corals also make a great place for butterflyfish to shelter in and under. Without healthy corals, then fish like these will become more and more scarce.

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In Biodiversity Tags Butterflyfish, corals, coral reef, fish, fish species, biodiversity
Comment
Featured
In a nutshell – where I stand on the proposed Norfolk Island Marine Park
September 18, 2026
In a nutshell – where I stand on the proposed Norfolk Island Marine Park
September 18, 2026

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?

Read more →
September 18, 2026
No seagrass, but plenty of turtles
September 13, 2026
No seagrass, but plenty of turtles
September 13, 2026

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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September 13, 2026
Watching El Niño from Norfolk Island
September 6, 2026
Watching El Niño from Norfolk Island
September 6, 2026

El Niño is strengthening across the Pacific, but that does not tell us exactly what the coming months will bring to Norfolk Island. After a long wet spell, I am watching our rainfall and water supplies more closely again – and, underwater, keeping an eye on sea temperature, algae, coral recruits and the fish that turn up on the reef.

Read more →
September 6, 2026
What the world’s reefs are telling Norfolk Island
September 2, 2026
What the world’s reefs are telling Norfolk Island
September 2, 2026

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.

Read more →
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.

Read more →
August 25, 2026
Endemic, native, undescribed – what do these words actually mean?
August 24, 2026
Endemic, native, undescribed – what do these words actually mean?
August 24, 2026

A Norfolk chromis that turned out not to be Chromis fumea, a blenny found nowhere else, and a tiny goby that may not yet have a name. A look at what we mean by native, endemic, undescribed and newly described – and why scientific names sometimes change.

Read more →
August 24, 2026
What’s grazing in the green stuff?
August 16, 2026
What’s grazing in the green stuff?
August 16, 2026

A proliferation of Bryopsis on the reef has brought some beautiful little underwater grazers with it. I follow the trail from sap-sucking sea slugs and egg masses to a bigger question – why is there so much Bryopsis around at the moment?

Read more →
August 16, 2026
The clam beneath Emily Bay
August 8, 2026
The clam beneath Emily Bay
August 8, 2026

I’ve seen the beautiful shells of Laciolina chloroleuca in Emily Bay for decades, but I’d never really stopped to wonder where the living animals were. It turns out they may be buried half a metre beneath the sand. A closer look at an easily overlooked clam, its extraordinary shell markings, and the hidden life beneath our lagoon.

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August 8, 2026
Reflections of an accidental marine scientist
August 1, 2026
Reflections of an accidental marine scientist
August 1, 2026

What I thought would be a steady plod towards retirement, with plenty of time spent nursing grandchildren, was abruptly upended exactly six years ago today. This is the story of how an environmental catastrophe changed the course of my life – and led me to reinvent myself. It is a reflection on how, and why, I became an accidental marine scientist.

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August 1, 2026
From ridge to reef: unpicking the Waterway and Wetland Strategy
July 24, 2026
From ridge to reef: unpicking the Waterway and Wetland Strategy
July 24, 2026

Norfolk Island’s draft Waterway and Wetland Strategy will guide work for the next ten years. I support its intent, but it needs to be clear, practical and measurable – joining the dots from ridge to reef so we know whether public money is improving water quality and helping the reef.

Read more →
July 24, 2026

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