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Norfolk Island's Reef

Discover a fragile paradise – Norfolk Island's beaches, lagoons and coral reef
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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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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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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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Tonna melanostoma

Citizen science in action on Norfolk Island

February 28, 2022

My photos of the Tonna melanostoma, a giant underwater mollusc, are the only ones of the live animal in the public domain. We are so fortunate to have these special and rare creatures living in our coral-reef lagoons; their existence here serves to highlight what a special habitat Norfolk Island’s reef really is. It is an ecosystem that must be preserved at all costs.

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Tags Tonna melanostoma, Royal Belgian Society for Conchology, molluscs, tun shell, Emily Bay, Gloria Maris, ecosystem, rare sea snail
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Stylocheilus striatus – commonly called the lined sea hare, blue ring sea hare or furry sea hare

Furry sea hares as eco-warriors

December 12, 2021

Stylocheilus striatus – commonly called the lined sea hare, blue ring sea hare or furry sea hare – have appeared in numbers at one end of the shallows of Emily Bay. These little sea hares are great to have around as they consume the toxic blue-green alga that fish and other herbivores don’t or can’t eat or tolerate.

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Tags sea hares, eco-warriors, ecosystem, algae, nutrients, pollution, water quality, Emily Bay
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Surge wrasse - Thalassoma purpureum

Nuptial colouration in blennies

October 12, 2021

Warmer water and some behavioural changes: some fish are getting their nuptial colours on, while others have started incubating eggs in their mouth. It is all happening ‘out on a swim’. Catch up on the last week in Norfolk Island’s lagoons here.

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Tags nuptual colouration, Blenny, Emily Bay, Raft, pontoon, Southern Eagle Ray, environment, ecosystem, water quality
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Featured
From coral scar to aatuti farm
June 20, 2026
From coral scar to aatuti farm
June 20, 2026

Aatuti are bold little algae farmers, but how does one of their farms begin? Over the past year, I have been following several coral patches as small white scars became algal footholds, then larger defended patches. I still cannot say what caused the first wounds, but the photo sequences show something fascinating: on a reef where algae is already gaining ground, even tiny changes on the coral surface can become part of a much bigger story.

June 20, 2026
Norfolk’s water quality – when action is reported as outcome
June 15, 2026
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.

June 15, 2026
How surgeonfishes got their name
June 14, 2026
How surgeonfishes got their name
June 14, 2026

Surgeonfish are named for the sharp little scalpels near their tails, but on Norfolk’s reef their more useful work happens at the other end. Pencil surgeonfish, bluespine unicornfish and their relatives help browse algae across the reef – a small daily job that becomes very valuable on an algae-rich lagoon reef like ours.

June 14, 2026
A shrimp storm
May 28, 2026
A shrimp storm
May 28, 2026

While setting my research cams last week, I swam into what looked like an underwater snowstorm. It appeared to be the aftermath of a mass moulting event, with large numbers of tiny, translucent shrimp-like exoskeletons drifting together near the surface.

May 28, 2026
Kingston dredging: what happens when a reef does not fit the framework
May 28, 2026
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.

May 28, 2026
Kingston dredging: the project advances, the questions remain
May 24, 2026
Kingston dredging: the project advances, the questions remain
May 24, 2026

Kingston dredging is edging closer, and the paper trail is growing. This post brings together earlier correspondence with the Department and the latest media release so readers can see what has been asked, what has been answered, and what still remains unclear about the project, its rationale, and the protections proposed for the reef.

May 24, 2026
The lime-green coral in Slaughter Bay – a 40-year paper trail
May 17, 2026
The lime-green coral in Slaughter Bay – a 40-year paper trail
May 17, 2026

Green Mountain – the name I give this coral in my database – is a coral I’ve photographed for years as I swim past. Then I found its backstory in the Norfolk Island National Parks archives: a rough map, reused paper, a note in the margin – ‘still thriving’. That’s how baselines begin.

May 17, 2026
What Norfolk Island’s reef tells us about environmental blind spots
April 5, 2026
What Norfolk Island’s reef tells us about environmental blind spots
April 5, 2026

The Kingston dredging proposal on Norfolk Island raises a bigger question than dredging alone: how well do standard environmental assessment tools capture the real significance of a remote and unusual reef system like Norfolk Island’s?

April 5, 2026
Hammer coral time!
March 30, 2026
Hammer coral time!
March 30, 2026

Hammer corals have unique tentacles that are large, fleshy, and tubular; these terminate in a ‘T’-shaped, hammer-head or anchor. Beneath all these softly waving tentacles is an extraordinary skeleton structure, which helps define them as a large polyp stony coral.

March 30, 2026
Norfolk Island’s fishes: drifters, residents and the ones still missing
March 24, 2026
Norfolk Island’s fishes: drifters, residents and the ones still missing
March 24, 2026

Norfolk Island’s fish fauna reflects both connection and isolation. Some species may arrive from elsewhere as drifting larvae, some populations appear to persist locally, and some fishes known from islands on either side of Norfolk have still not been recorded here. This post looks at what old survey work, regional checklists and genetic studies suggest about that more complicated picture.

March 24, 2026

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