A pair and a spare – snubnose darts on 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 blog is rated in the Top 20 Coral Reef Blogs in the world.

DAY 23 – MARCH FOCUS ON NORFOLK ISLAND’S REEF

Norfolk Island’s reef is small and intimate. We can count the numbers of some species of fish on one hand, which is how I can watch the comings and goings with interest as I swim among them. I love the stories that play out and which I get to witness, and these snubnose darts (Trachinotus blochii) are a case in point.

There are a pair of them that always hang out together. I have images going back to March 2020 of the same individuals, and I can tell they are the same ones because one of them has a slight nick out of the top fork of its caudal fin. They are what I call a ‘sometimes’ visitor. They come. They go. But more often than not they seem to reappear in March and disappear in November.

I have no idea what sex they are, but I do know that in mid 2021 they were joined by a much larger snubnose dart, which I assumed was a male. He was an impressive specimen, much larger, with a streamlined body of mirrored metallic silver. He stayed with the pair for a month or so, although I can’t tell you if he was with them 24/7 or if he came and went as the mood took him.

The juvenile trevally, smaller than my little finger

By October 2021, the pair were once again on their own, happily hanging in their favourite spots, either at the Lone Pine end of Emily Bay, or in the shallows of Slaughter Bay (although occasionally you will see them swimming between these two places). This time they were joined by a tiny passenger, a juvenile (baby) trevally. I’ve put a ring around him in the photo because he is so hard to see otherwise. If you click on the photo, it will enlarge.

I like to take credit for that baby’s introduction to the pair. The baby trevally had attached himself to me, swimming beside and around me for more than half of my hour-long swim. I am sure anyone who was watching from the shore thought I was demented as I spun around trying to capture him on film, so closely was he glued to my side.

I probably represented food or protection of some kind, but even so, it was quite the privilege to connect with this busy, happy little thing as he darted in and out of my field of vision. At the end of my swim, I found the two resident snubnose darts close to the Lone Pine end of Emily Bay. My little companion transferred his affiliations in a quicksilvery flash!

Fast forward to last week, in March 2023, and there were the pair of besties back foraging in Slaughter again. And there with them was a third wheel. A juvenile (teenager) trevally.

A tiny trevally inside the circle, October 2021

A trevally with the two darts, March 2023

The much larger (male?) snubnose dart with the two smaller residents in August 2021

I wonder? What do you reckon?

He is quite a bit bigger than before, but could it be the same one, 18 months later? The three of them circled around me a few times as I took their photo and then swam off.

Maybe I am being fanciful. But I do hope it was the same little trevally, because it certainly makes a delightful story.

There’s a lovely postscript, too. A week ago I spotted a young snubnose dart on its own in Emily Bay. Is it the progeny of the tryst made back in mid-2021 when the larger dart gatecrashed our lagoon, seemingly to court our two ‘sometimes’ residents? Who knows.

Why are there always so many more questions than answers?

Jun 13, 2025

Glimpses of recovery: what the reef could be if we let it

Day 6 of this photo series from Norfolk Island coincides with the final day of the UN Ocean Conference in Nice. After a week of documenting decline, today’s post offers a different view – what reef recovery can look like when conditions improve. Drought in 2024 gave the reef a break, and the results were unmistakable: healthier corals, lower disease, and more fish. This is what’s possible if we act.

Jun 12, 2025

Warning signs: quiet and unnoticed collapse of two coral colonies

Day 5 of my blog series for the UN Ocean Conference: two long-lived coral colonies in Norfolk’s lagoon died quietly from disease. No drama – just slow collapse and overgrowth by algae. A reminder that not all reef losses are loud, but they are happening.

Jun 11, 2025

Warning signs: what Norfolk Island’s reef is telling us

Day 4 of a week-long photo series from Norfolk Island, shared during the UN Ocean Conference in Nice. Today’s post spotlights a Hydnophora pilosa colony where white syndrome appeared suddenly and spread quickly, taking out around a quarter of the coral. In the months that followed, algae quietly filled the gap – a subtle but telling shift from coral to algae that’s happening across the reef.

Jun 10, 2025

Warning signs: coral disease takes hold

In Day 3 of this blog post series, published while leaders gather at the UN Ocean Conference in Nice, we see Norfolk Island’s coral reef lagoon quietly delivering a stark warning: recurrent land-based pollution, coral disease, and delayed decisions are dismantling this ecosystem in real time.

Jun 9, 2025

Warning signs: coral growth anomalies – the slow cancers of the reef

Day 2’s post coinciding with the UN Ocean Conference looks at coral growth anomalies – sometimes called coral ‘cancers’. These slow-moving diseases quietly weaken coral colonies, making them far more vulnerable to storm damage and algal takeover. On Norfolk Island’s reef, I’ve watched this exact process play out over several years. This is how chronic stress silently dismantles coral ecosystems.

Jun 8, 2025

Warning signs: shifting baselines on Norfolk Island’s reef

Today is World Ocean Day — a timely moment to launch my week-long blog series on Norfolk Island’s reef. Each day this week, I’ll be sharing photo essays that document the slow but steady pressures reshaping this fragile reef. Today: how shifting baselines make us blind to what we’ve already lost.

Apr 29, 2025

The Governance–Government Vacuum: Norfolk Island’s Forgotten Ecology

A personal reflection on Norfolk Island’s coral reef environment, political denial, and what John Wyndham’s The Kraken Wakes can still teach us about slow-moving disasters — and why this election matters more than ever.

Feb 20, 2025

Cute as buttons – Astrea curta

Astrea curta corals are ‘small, moderately plocoid [flattened], distinct, and almost circular’ . Normally grey-green in colour, you can see from the images here, ours are often beautiful rich gold, although they do vary. They have a neat growth habit and button-like corallites, which can grow in columns, spherically or flattened. Large colonies of these can form gorgeous undulating bumps.

Jan 26, 2025

From 'Watch' to 'Warning'

Last week, the chance of coral bleaching in Norfolk Island’s inshore lagoons was raised from ‘Watch’ to ‘Warning’ and will more than likely rise to Alert levels one and two in coming weeks. So why do I worry about water quality all the time when bleaching seems inevitable these days and so the reef is probably doomed anyway? Read on to find out.

Jan 4, 2025

From little things – watching them grow

Small numbers of different fish species is not an unusual phenomenon on Norfolk Island’s reef, but it does demonstrate what a tiny, precious, coral reef ecosystem we have, when we can count individuals on one hand and watch each of them grow, like these little blackeye thicklips, a member of the wrasse family.