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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.

One of the pair of ‘sometimes’ resident snubnose darts, Norfolk Island

A pair and a spare – snubnose darts on Norfolk Island's reef

March 23, 2023

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.

View fullsize A tiny trevally inside the circle, October 2021
A tiny trevally inside the circle, October 2021
View fullsize A trevally with the two darts, March 2023
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?

The juvenile in March 2023

In Fish species Tags Snubnose dart, fish, fish species, fish behaviour
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