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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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    • Everything Else
    • Kingston, Norfolk Island
    • Nudibranchs, Sea Slugs and Flatworms
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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.

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
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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
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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
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Featured
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
Celebrating Biodiversity Month on Norfolk Island
Sep 7, 2025
Celebrating Biodiversity Month on Norfolk Island
Sep 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.

Sep 7, 2025

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