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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.

29 Mar 2021 (50).jpg

The sea-wolves of Emily Bay

January 21, 2021

Another underwater drama has been playing out in the shallows of Emily Bay over the last few weeks.

At the end of November, I photographed a mass of newly hatched fry gathered around what looks like an old oil drum. Over time they’ve grown bigger; In the following weeks I saw some of them in open water having left the safety of the drum's coral crevices, and other refuges, to head for the reef.

View fullsize 19.11 (2)_reduced.jpg
View fullsize 23.11 (143)_reduced.jpg
View fullsize 19.11 (1)_reduced.jpg

Attracted by the easy pickings, I then watched as the silver trevally – Pseudocaranx sp 'dentex' – arrived. Like a sleek pack of wolves they swept around, in and out of the drum scooping up whatever they could. The fry shrank back, huddling together, trying to stay out of the maelstrom and away from so many hungry mouths.

The fry’s numbers have been depleted considerably by these regular visits made by the insatiable trevally, but still some survive and are growing bigger by the day. They are mainly juvenile big eyes – the Norfolk cardinalfish, or Ostorhinchus norfolcensis – but there are also some juvenile smoky pullers – Chromis fumea – in their number.

Last week another visitor arrived on the scene. This time a lone blue trevally – Carangoides ferdau. It's agonising to watch, but then you also have to admire these sleek streamlined hunters as they speed around the tight corners, swooping on anything in their path.

View fullsize Blue trevally - Carangoides ferdau
Blue trevally - Carangoides ferdau
View fullsize Silver trevally - Pseudocaranx sp 'dentex'
Silver trevally - Pseudocaranx sp 'dentex'
View fullsize Silver trevally - Pseudocaranx sp 'dentex'
Silver trevally - Pseudocaranx sp 'dentex'
View fullsize Silver trevally - Pseudocaranx sp 'dentex'
Silver trevally - Pseudocaranx sp 'dentex'

You probably don’t realise it, but this daily drama unfolds right by your feet as you wade into the peacock-blue shallows of Emily Bay for a swim.

As an aside, in previous years, much of this action happened beneath the raft, where there was a fantastic underwater 'cave' for the babies. The new raft has very little space beneath its rafters because of the way it has been constructed. And of course the weed hasn't yet had a chance to grow back as luxuriantly as it was before. So far this year, very few fish have decided to make it their nursery. It will be interesting to see if that changes as the weed grows. I'll be watching with interest.

View fullsize February 2020 - beneath the raft
February 2020 - beneath the raft
View fullsize January 2021 - beneath the raft
January 2021 - beneath the raft
← Once a boy, always a boy – the marbled parrotfishUnderwater wars! Aatuti versus the elegant wrasse →
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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