September full moon on Norfolk Island

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.

More changeable weather this week with poor visibility in the bays curtailing some of my observations, but the full moon last night brought us some beautiful, settled weather, right on cue, which meant I was able to get out into Slaughter Bay for the first time in ages.

What greeted me wasn’t too pretty either. There is one area of coral I have been watching since the marine researchers from the Sydney Institute of Marine Science were here in March and alerted me to the onset of white syndrome, or white band disease. I have kept an eye on it since then and watched as the colony has gradually died. This week it was virtually unrecognisable, covered by a thick growth of algae. You can see the progression of the disease, below. Heartbreaking.

4 May 2021

11 June 2021

20 September 2021

A sure sign that things are warming up in the water was the sighting of a couple of Lady Musgrave blennies, Cirripectes chelomatus, out and about for the first time in yonks. I have seen them over winter, but it has been incredibly fleeting as they dashed for cover. This week my regular guy was happy to sit and be photographed. No sign of the chestnut eyelash blennies, Cirripectes castaneus, yet, though.

From now on, I expect to see these cheeky guys more and more. They tend to sit up on a prominent piece of coral, flutter up and then dive quickly back down and hide. And they will start to change colour as the season progresses to a beautiful greeny yellow with their blue tails. The first two images are from today. The others are to show you what I expect them to look like very soon.

Lady Musgrave blenny - Cirripectes chelomatus 20.09.21

17 November 2020

2 February 2021

Another fun photograph was of (I think*) a redcap triplefin, Enneapterygius rufopileus. These guys are a master of disguise. Probably less than 1 cm in length, they can be really hard to spot. Blink and they’re gone. The other image is of (I think*) a Doug’s eviota, Eviota hoesei. Similar in size to the redcap triplefin, and looking like a diminutive jewel, he has a black spot near his tail.

Redcap triplefin - Enneapterygius rufopileus

Doug's eviota - Eviota hoesei

To round off the week out on a swim, I thought I’d post one of my favourite butterflyfish, the vagabond butterflyfish, Chaetodon vagabundus. This is one of a pair that were happily flitting around in Slaughter Bay yesterday.

Vagabond butterflyfish - Chaetodon vagabundus

When I first started observing and photographing, I had no idea that there were so many variations on yellow, black and white among the butterflyfish. If you hop over to my reef fish page and scroll down to the Butterflyfish heading you will see what I mean.

*I've tried to get a definitive ID on these tiny critters on iNaturalist.org, but so far I've been unsuccessful.

October 28, 2026

When storms rearrange the reef

Sometimes the sea rearranges a reef in a matter of hours! In the third article of my six-part photographic series, I revisit corals broken, overturned or swept away by powerful swells and storm surges. Some disappeared altogether, while others found surprising ways to survive. Five photographic sequences reveal just how dramatically Norfolk Island's reef can change.

October 26, 2026

When the reef fights back – coral growth and recovery

Not every coral story ends badly! Among six years of underwater photographs are some wonderful examples of growth, survival and recovery. From corals that have grown spectacularly to others that have survived bleaching, breakage or even being turned upside down, this second article in my photographic series celebrates some of the reef's more encouraging stories.

October 24, 2026

The neighbours – six years of watching the same reef

When I began photographing Norfolk Island's reef in 2020, I simply recorded whatever caught my eye. Six years later, those photographs have become a record of individual corals and their changing fortunes – growth, competition, survival and loss. This is the first of six articles looking back at what I've seen, and sometimes what I wish I hadn't.

October 10, 2026

Pulling the rugosity from out of the reef

What do ‘rugosity’, structural complexity and channeling your inner fish have in common? Quite a lot, as it turns out. This week I’m looking at how all the lumps, bumps, branches, holes and ledges on a reef create habitat – with a brief detour into one of my long-standing tricks for navigating tertiary study: write down the jargon until it starts to make sense.

September 27, 2026

How does a sea slug smell?

It started with a close-up of a little Elysia and two rhinophores that looked like tiny rolled-up scrolls. Once I noticed them, I started going back through years of sea-slug photos and realised just how wildly different these sensory organs can be – ridged, rolled, curled, tubular and, in sea hares, distinctly rabbit-eared. So this week’s rabbit hole is all about how sea slugs ‘smell’ underwater, and why their noses come in so many different shapes.

September 19, 2026

The Elite Fleet sails in

Nearly six years ago, my very first blog post was about the strange blue and violet creatures that live at the ocean’s surface – a group I christened Norfolk Island’s ‘Elite Fleet’. Since then I’ve seen plenty of bluebottles and the occasional violet sea snail, but never a by-the-wind sailor. Until this morning. Velella velella is not a true jellyfish, but a colonial hydrozoan with a transparent sail that lets the wind help carry it across the ocean. So what exactly is this extraordinary little creature, how does it ‘sail’, and what connects it to the rest of the fleet?

September 18, 2026

In a nutshell – where I stand on the proposed Norfolk Island Marine Park

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?

September 13, 2026

No seagrass, but plenty of turtles

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.

September 6, 2026

Watching El Niño from Norfolk Island

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.

September 2, 2026

What the world’s reefs are telling Norfolk Island

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.