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Norfolk Island's Reef

Discover a fragile paradise – Norfolk Island's beaches, lagoons and coral reef
  • Home
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    • Norf'k Ilen's Language
    • Algae
    • Corals
    • Eels
    • Everything Else
    • Kingston, Norfolk Island
    • Nudibranchs, Sea Slugs and Flatworms
    • Octopuses
    • Out On A Swim Index
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    • Sharks
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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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Elysia marginata, Norfolk Island

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?

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In Sea slugs, Ecosystem Tags Algae, Bryopsis, nutrients, coral reef, Elysia, sea slugs
Comment

View across the cricket pitch to Old Military Barracks, Kingston, Norfolk Island

Norfolk’s water quality – when action is reported as outcome

June 15, 2026

A recent Australian Government media release presents investment, monitoring and catchment works as progress on Norfolk Island’s water quality. Some of that work is useful, and some of it was badly needed. But activity is not the same as proven improvement. This post looks at Kingston sewerage, wetlands, cattle, acid sulfate soils, groundwater and reef health, and asks whether Emily Bay and Slaughter Bay are actually being better protected.

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In Water quality, Environmental degradation, Corals, Ecosystem Tags Water quality, Kingston, Norfolk Island, coral reef, Reef health, sewerage, public health, Acid sulfate soils
2 Comments

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
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Quality Row, Kingston, Norfolk Island, January 2025. The year began deep in drought.

A year in review – 2025 on Norfolk Island's reef

December 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.

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In Ecosystem Tags corals, rainfall, Coral disease, drought, Norfolk Island, Review
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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

Nepean Island (left) and Phillip Island (right) to the south of Norfolk Island are free of rats. Rat-free seabird rookeries are important for the health of coral reefs.

Poop power

June 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.

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In Ecosystem Tags Fish, coral health, seabirds, faeces, poop
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The view across Emily Bay and Slaughter Bay’s contiguous reef at low tide. Quintal’s Passage can be seen as two parrallel lines of rocks. It runs from Emily out to sea.

Blasting a passage through the reef, Norfolk Island

April 6, 2024

We have shaped Kingston, Norfolk Island, to suit our own ends, whether it is by draining the swamp, undertaking major earthworks, or by using it for agriculture and grazing. Our interventions have placed the reef at risk. But simultaneously, the confluence of human activity and a unique natural environment have created a place of incredible significance, which deserves some special management to preserve all its facets.

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In Ecosystem Tags Kingston, World Heritage Area, Norfolk Island, Water quality, Quintal's passage, coral reef, coral health, coral disease, Colonial settlement
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Norfolk Island’s inshore reef during low tide and at sunrise

A year in review – 2023 on Norfolk Island's reef

December 29, 2023

Sadly, the year didn’t bring any obvious improvements to Norfolk Island's reef in terms of reductions in incidences of coral disease, or runaway algal growth. And while some fish seem to have departed the scene, another species has re-established its home. Here’s a rundown of what I've been doing during the last four years of observations, and what I've seen happening on our reef in 2023.

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In Ecosystem Tags 2023, Norfolk Island, coral reef, Fish, fish species, water quality, coral health, White syndrome
4 Comments

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

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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Tiny shells collected from the beach, Norfolk Island 1990s

You don’t always know what you’ve got – ’til it’s gone

March 8, 2023

On Norfolk Island, Australian Marine Parks recently issued a no-take area in our coral reef lagoon habitats. My hope is that with these bans in place, in addition to curbing runaway algal growth, there will be an improvement across the reef ecosystem in a number of different species, with subsequent knock effects for others, including for our molluscs, wrasse and octopus species.

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In Ecosystem Tags Environmental protection, no-take zones, algae, water quality
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Be like Senator David Pocock - wear a rashie

Sunbeams and sunscreens

December 19, 2022

Did you know that sunscreen is highly toxic?

From 1 January 2021, Hawaii banned all sunscreens containing the reef-harming chemicals oxybenzone and octinoxate, and with good reason. This radical action was taken because unsafe sunscreens can, and have, caused ecological ruination to coral reefs.

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In Ecosystem Tags corals, coral reef, coral reproduction, fish, Fish reproduction, Sunscreens, reef-safe sunscreen, Norfolk Island
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A flatworm, Pseudobiceros sp, dining on the tunicates

Sea squirts – friend or foe?

October 17, 2022

Emily Bay and Slaughter Bay have recently experienced a significant increase in the numbers of overgrowing tunicates. In this post I take a look at these critters – which, incredibly, are distant cousins to humans – and ask some questions about their presence and impact on our coral reef ecosystem.

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In Ecosystem Tags tunicates, sea squirts, coral reef, corals, SlaughterBay, Emily Bay, ecosystem, biofouling, flatworms, ocean, Norfolk Island
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Featured
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.

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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.

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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?
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.

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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.

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July 24, 2026
Reef reality in pictures
July 13, 2026
Reef reality in pictures
July 13, 2026

Let the pictures do the talking. This is the reality on Norfolk Island’s reef today, laid out in a two-minute video.

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July 13, 2026

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