Enormous surf, squally winds and poor viz!

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.

On the 26 May, we witnessed a clear sky and a lunar eclipse. For a few days before this event, we’d had cool blustery winds from the south and southwest. But the day following it became calm and settled, so much so even my weather app decided winds of less than 1 km an hour should be expressed as ‘calm’!

The following day, the weather quickly turned again, and the remainder of this week has seen enormous surf, squally winds and poor visibility in the water. In fact, just about zero viz!

Today is the first day of winter, with cool winds blowing straight up from Antarctica. Many readers will laugh, but for a sub-tropical island, we are really feeling the wind chill at the moment. In a conversation I had with a fellow swimmer this morning, we agreed that if you just keep swimming, you don’t even notice it getting cooler. It really is a case of mind over matter. When it gets a little cold in the water, or rather when I get out, I always remind myself that there are reef fish in there, and they don’t like cold water! Like the beautiful Three-striped butterflyfish, Chaetodon tricinctus, drawn by @narwee_sketch for us this week.

Despite the conditions, I only missed swimming on one day, and I still managed to see a few beautiful things during the week. I always love to capture a photo of the green moon wrasse, Thalassoma lutescens. This one is giving me a quizzical sideways glance! And I was lucky enough to witness an initial phase surge wrasse, Thalassoma purpureum, eating a crab lunch.

Another exciting observation this week was the turtle. It always feels such a privilege to come around a corner and face to face with one of these amazing creatures.

Surge wrasse - Thalassoma purpureum

Green moon wrasse - Thalassoma lutescens

Green sea turtle - Chelonia mydas

Tonna melanostoma

Professor Andrew Baird, a researcher from James Cook University contacted me this week about my images of corals on this website (check them out here). So he could have a better look, I uploaded around 350 of them to a Dropbox folder. He has kindly gone through them, giving me IDs on many, and asking for some further images on a few he thinks maybe rare or endemic to Norfolk Island.

This is incredibly exciting. Andrew and a colleague plan to visit in August to have a look for themselves.

And, saving the most exciting news til last, and a little delayed as I have been waiting on confirming an ID: on 10 May I photographed a tun shell in the bay and uploaded the images to iNaturalist. Many regular swimmers will see these from time to time in the deeper areas of our bays, although sightings are definitely becoming rarer. Tuns are a large species of sea snail, or mollusc. This particular tun was quickly identified as being Tonna melanastoma. This truly is an amazing observation. There have been very few specimens identified over the last century, often trawled up from depths of 300 m. Apparently, this is the only photograph of a live mollusc in the public domain.

Since then, I have co-authored a paper with Chris Vos, a Belgian conchologist with some 45 years’ experience in the field. It is going to be published in August in a journal in Europe. I’ll definitely keep you posted on this one!

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.

August 25, 2026

When the map changes

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.

August 24, 2026

Endemic, native, undescribed – what do these words actually mean?

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.

August 16, 2026

What’s grazing in the green stuff?

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?

August 8, 2026

The clam beneath Emily Bay

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.

August 1, 2026

Reflections of an accidental marine scientist

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.

July 24, 2026

From ridge to reef: unpicking the Waterway and Wetland Strategy

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.

July 13, 2026

Reef reality in pictures

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

June 28, 2026

The red seaweed behind low-methane beef

A small red seaweed on Norfolk’s reef has become part of a much bigger story. Asparagopsis taxiformis can look like a delicate red feather duster or, at another stage of its life cycle, like a tiny cottony pom-pom. It is beautiful, easily overlooked, and now being used in the cattle industry to help reduce methane emissions. This post looks at the reef oddity behind the low-methane beef story – and why repeated local observation can be more useful than it first appears.