‘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.
Sabre squirrelfish, Sargocentron spiniferum, seen at Norfolk Island, increasing its known range southwards by 750 km
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.
Read MoreA young Chromis norfolkensis, Norfolk chromis
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.
Read MoreBluespine unicornfish, Naso unicornis. Note the two scalpels at the base of its tail. These fish have been found to live to at least 50 years old. Norfolk Island
Surgeonfish are named for the sharp little scalpels near their tails, but on Norfolk’s reef their more useful work happens at the other end. Pencil surgeonfish, bluespine unicornfish and their relatives help browse algae across the reef – a small daily job that becomes very valuable on an algae-rich lagoon reef like ours.
Read MoreEchidna nebulosa, snowflake moray, Norfolk Island
How did the snowflake moray get its proper (scientific) name Echidna nebulosa, and what does it have to do with Australia’s famous and iconic marsupial, the echidna? Read on to find out more …
Read MoreBlue-barred parrotfish (Scarus ghobban), last seen in September 2021
In my ‘Year in review for 2023 on Norfolk Island’s reef’, published in December 2023, I made a few observations about the apparent disappearance of some fish species from Norfolk Island’s lagoons. I thought I would revisit these, principally because since December there has been so much additional fish activity here, with some exciting population increases and a few new species turning up.
Read MoreA territorial banded scalyfin, Parma polylepis (aatuti), Norfolk Island
The banded scalyfins and the multispine damselfish are arguably two of the most common species in Norfolk Island’s lagoons. People often confuse them, particularly the juveniles, so here are some photos to clarify which are which. Once the differences have been pointed out, you’ll never confuse them again.
Read MoreA small school of scissortail sergeants with one interloper, an Indo-Pacific sergeant, Norfolk Island
There are a few fish species in Norfolk Island’s bays that are easily mixed up. Here’s four commonly confused pairs, with a few pointers to help you identify them.
Read MoreMy grandson
What will my grandson see when he is old enough to snorkel on Norfolk Island’s reef? Will there be anything left as I know it? Or will he think it is all great because of that hoary old phenomenon called ‘shifting baseline syndrome’? This record of all my photos and observations will give him some idea of what we had in our bays in the 2020s.
Read MoreBlack Blenny, Enchelyurus ater found in Slaughter Bay, Norfolk Island
This is a copy of the Australian Fishes journal post about new fish sightings on Norfolk Island: ‘This observation [of a black blenny] highlights the power of citizen scientists working with professional ichthyologists to achieve important outcomes,’ Mark McGrouther, Senior Fellow at the Australian Museum.
Read MoreOne of the pair of ‘sometimes’ resident snubnose darts, Norfolk Island
Norfolk Island’s reef is small and intimate. We can count the numbers of some species of fish on one hand, and that 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 – these snubnose darts (Trachinotus blochii) are a case in point.
Read MoreThreadfin butterflyfish, Chaetodon auriga, Norfolk Island
Butterflyfish are flighty, brightly coloured and beautifully conspicuous on our coral reef in their bright yellows and oranges, white and black livery. On Norfolk Island we regularly see fourteen species, just a small portion of the more than 100 species, globally. Large numbers of butterflyfish are a good sign of a healthy reef.
Read MoreYellowstripe goatfish, Mulloidichthys flavolineatus
If you go for a snorkel on Norfolk Island’s reef, one family of fish that you are bound to see is members of the goatfish family. I have seen have six different species inside our lagoons. You can see them all here.
Read MoreAdult female elegant wrasse, Norfolk Island
It’s always fascinating to see how fish change in appearance as they mature. Today’s blog post features the elegant wrasse, Anampses elegans. But not only do they change how they look, they also change how they socialise and move about the reef.
Read MoreA bluestreak cleaner wrasse (Labroides dimidiatus) cleaning a coral sea gregory (Stegastes gascoynei)
Bluestreak cleaner wrasse, Labroides dimidiatus, are important critters on our coral reefs. These fish offer a swim-through full-body maintenance shop for other fish species – their clients – nibbling away dead skin and any nasty ectoparasites that might be living on their clients. There’s a lot to be learned about a reef from watching these busy little fish.
Read MoreA peacock damselfish – Pomacentrus pavo
Today I am featuring a fish called the peacock damselfish – Pomacentrus pavo. On our tiny reef, you can often count the fish of a particular species on one hand, and the peacock damselfish is a perfect example of this. Our last baby peacock damselfishes appeared in mid-February (2021), but this year juvenile fish for any of the species in our bays have been hard to find. Maybe they are later this year?
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