‘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.
From front to back: raccoon butterflyfish; blackback butterflyfish; three-striped butterflyfish Back right: Threadfin butterflyfish
Butterflyfish are ‘corallivores’, that is, they feed mainly on coral polyps and the energy-rich mucous that these produce. Corals also make a great place for butterflyfish to shelter in and under. Without healthy corals, then fish like these will become more and more scarce.
Read MoreThe black-mouthed tun snail as it clambered over the reef
When I took my first photographs of the live black-mouthed tun snail (Tonna melanostoma) and posted them on iNaturalist, I had no idea that there were no other – as in none, zip, nada – images of it in the public domain; just one of a broken shell that is housed in the Auckland Museum. This is my featured image for 3 March.
Read MoreBait fish, Emily Bay, Norfolk Island, September 2020
For 2 March I've chosen to feature a ball of bait fish photographed in September 2020. There is something awe-insipring about being encircled by a huge seething mass of tiny fish all moving in unison. It takes your breath away. The question is, where have these bait balls gone?
Read MoreHealthy montipora coral on Norfolk Island’s reef
After three years of observations, I have a unique library of some 80,000 images recording life in Norfolk Island’s lagoons. So I thought it would be worth spending the month of March looking back to see what has changed in that time and what hasn’t. Each day I will feature a different image. For 1 March I have picked a simple brown coral – a plate coral from the genus montipora. Read on to see what is happening to our montipora now.
Read MoreWhite-speckled sea hare, Aplysia argus, in Emily Bay, Norfolk Island
Sea hares, little submarine shreks that lumber their way slowly around intertidal zone are fascinating, and quite common, although most people won’t have heard of them. Their appetite for algae makes these a really useful species to have in our bays, along with parrotfish, sea cucumbers and sea urchins. And it is the algae that dictates their colouring.
Read MoreHannah and Trish with Doris
This morning marked the end of a four-month journey for Doris the green sea turtle. From a sick, emaciated turtle with lesions across her shell, and covered with an unhealthy growth of algae, she has been transformed to glossy beautiful health. Hannah slid Doris over the side of the boat and back into the bosom of the ocean, her home. We’ll miss her, but as she swam away, our hearts sang, too. She’s back where she should be.
Read MoreHornpike long tom - Strongylura leiurus
It only takes your observation of one little fish out of its previously understood ‘comfort zone’ to add to a body of evidence that may prove, or disprove, scientific theories, which may then in turn be used to inform government policy on climate change, preserving the environment, and much more. That is citizen science at work. And it can be powerful and fulfilling.
Read MoreLone Pine photographed from Emily Bay, showing the freshwater layer caused by innundation from the creek.
It’s always a good time to take stock of the year that was, so I’ve been thinking about what 2022 held for Norfolk Island’s reef. La Niña superimposed on La Niña has meant copious rainfall and a lagoon under stress: more algae, more coral disease, fewer fish. Here’s a quick run down of what has been happening on our reef during 2022.
Read MoreBe like Senator David Pocock - wear a rashie
Did you know that sunscreen is highly toxic?
From 1 January 2021, Hawaii banned all sunscreens containing the reef-harming chemicals oxybenzone and octinoxate, and with good reason. This radical action was taken because unsafe sunscreens can, and have, caused ecological ruination to coral reefs.
Read MoreBlack-mouthed tun snail, Tonna melanostoma
The black-mouthed tun shell’s egg mass is photographed almost daily over a period of six weeks, from the morning they are laid until becoming dislodged from their rock after a period of big swells and storm surges.
Read MoreIt’s been widely reported since the 1960s, at least, that nutrient-laden water flowing out the channel into Emily Bay is having a detrimental effect on Norfolk Island’s reef – a reef where it is thought that as much as 30 per cent of the corals are as yet undescribed. Are we going to do something about it before the reef has gone? Because, quite seriously, we have no time left to lose.
Read MoreDoris in her rehab tank
The following update on Norfolk Island’s rescue turtle, Doris, was released by Australian Marine Parks on 7 November 2022. For more information on Doris follow the hashtag #operationdoris.
Read MoreAt this time of year, as the mating season begins, the delightful little Lady Musgrave blennies, Cirripectes chelomatus, change colour from dark inky blue black with a few barely visible red spots to a showy and vibrant mustard yellow.
Read MoreA flatworm, Pseudobiceros sp, dining on the tunicates
Emily Bay and Slaughter Bay have recently experienced a significant increase in the numbers of overgrowing tunicates. In this post I take a look at these critters – which, incredibly, are distant cousins to humans – and ask some questions about their presence and impact on our coral reef ecosystem.
Read MoreDoris, a young green sea turtle, in a bad way
One of our Norfolk Island turtles was covered in an unsightly algal growth. Not just her shell but over her eyes and her flippers too. I could see she needed help, but we had no facilities to nurse a sick turtle; however, with a strong community behind us, and plenty of caring people, this is just what we did. This is how #operationdoris unfolded.
Read MoreCorals found in the lagoons of Norfolk Island
There were three confirmed coral spawning events on Norfolk Island’s coral reef during the 2021–2022 season. The evidence for these has now been published in Galaxea, Journal of Coral Reef Studies. Written by Professor Andrew Baird, chief investigator at the ARC Centre of Excellence for Coral Reef Studies, I am very kindly cited as a co-author because of my observations of these events. Read here to find out more.
Read MoreSurge wrasse – Thalassoma purpureum
Wrasse and parrotfish often get confused, but they each have quite differen roles to play on our reefs. Parrotfish are vital to the health of coral reefs. They clean up the surface algae that live on and compete with the coral. Read more to find out how they differ.
Read MoreSea cucumber, class Holothuroidea
The beautiful sand of Emily Bay, Norfolk Island, didn’t get there by accident. It is the direct result of the hard pooping work of generations of marine animals, including parrotfish and sea cucumbers. This post takes a closer look at sea cucumbers and their role in the coral reef’s ecosystem.
Read MoreEmily Bay: Paragoniastrea australensis, also known as the lesser star coral, is a species of stony corals in the family Merulinidae. It occurs in shallow water in the Indo-Pacific region. (Source Wikipedia)
We have some beauties when it comes to brain corals inside our lagoons. They are quite amazing, and a hugely important part of a healthy reef. Here’s the low down!
Read MoreThe Norfolk chromis, or Chromis norfolkensis
Norfolk Island now has a new species of fish. What was once classified as Chromis fumea has been recognised as a separate species, Chromis norfolkensis.
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