No, it's not a parrotfish! — Norfolk Island's Reef

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.

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I often get people excitedly telling me how they have seen a parrotfish. And it is quite possible that they have. But to be honest, the few parrotfish that we do have are rather dull when compared with their more flamboyant wrasse cousins and there are very few of them, both in numbers of parrotfish species and in the numbers you will see of each one. If I see a parrotfish, any parrotfish at all, it is rare. And when I do see them it is often just an individual or possibly a small family group. So it is more likely that the large brightly coloured fish they are telling me about is either a surge wrasse – Thalassoma purpureum, or a green moon wrasse – Thalassoma lutescens, both of which are plentiful in the lagoons.

Green moon wrasse - *Thalassoma lutescens*

I have observed five species of parrotfish inside the reef. You can find them all under P for parrotfish if you scroll down on my fish page on this website. Keep scrolling down to W for wrasse to see the amazing variety of these.

Parrotfish are a subspecies of the wrasse family. Like wrasses, they swim using their pectoral (side) fins, which can look a little like mini wings as they move through the water.

One of the features that sets them apart from wrasses is their toothy grin and fused teeth – about 1000 of them lined up in 15 rows – in a beak-like form, hence their name. They eat ‘microscopic filamentous bacteria that live on, and just a few millimeters underneath, the calcareous surface of the reef’, and to get at these they chow down on the hard coral skeletons. More teeth in their throat (plates known as a pharyngeal mill) grind the coral into a paste so they can extract the nutritious coral polyps and algae. What comes out the other end is beautiful white sand.

Wrasse, on the other hand, like to consume invertebrates, such as shrimps, crabs, sea urchins and gastropods. They have soft protractile lips to help them nibble.

Parrotfish are vital to the health of coral reefs. In places where they have been overfished, the ecosystem is not as productive. So perhaps it’s best to leave them where they are.

More information about parrotfish can be found in this fascinating article from the Smithsonian here: ‘Tough Teeth and Parrotfish Poop’, Ocean.

Bluebarred parrotfish - Scarus ghobban

Marbled parrotfish - Leptoscarus vaigiensis

Pacific Bullethead Parrotfish - Chlorurus spilurus

Palenose parrotfish - Scarus psittacus

Surf parrotfish - Scarus rivulatus

Fused front teeth of the bluebarred parrotfish

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.

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.