Black Blenny - a new record for Norfolk Island

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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DAY 25 – MARCH FOCUS ON NORFOLK ISLAND’S REEF

Today’s post is to highlight how little we still know about Norfolk Island’s reef.

Below is a copy of the Australian Fishes journal post about new fish sightings on Norfolk Island. You can find the original post here: Black Blenny - a new record for Norfolk Island

Author: Mark McGrouther, Senior Fellow at the Australian Museum.

This small fish in the image above was photographed by Susan Prior (@susanprior) in Slaughter Bay, Norfolk Island. Susan couldn’t identify the fish so she uploaded the observation identified simply as a ‘Ray-finned Fish’ to the Australasian Fishes Project.

Francois Libert (@francoislibert) subsequently correctly identified it to family, then Malcolm Francis (@francism) tentatively identified it as a Black Blenny, Enchelyurus ater. Malcolm tagged me for my input, so I referred the observation to Australian Museum Senior Fellow, Doug Hoese who confirmed Malcolm’s tentative identification.

Malcolm was particularly interested in Susan’s observation because for some years he has maintained a checklist of the coastal fishes of Lord Howe, Norfolk and Kermadec Islands. Malcolm noted that the Black Blenny had not previously been recorded from Norfolk Island.

This observation highlights the power of citizen scientists working with professional ichthyologists to achieve important outcomes. It also illustrates the fact that users shouldn’t be afraid to upload observations of fishes that they can’t identify. Most of the time someone will step up to the plate with an identification.

Thanks to everyone involved in bringing this new record to light.

Comments to the above post

Posted by francism: This is not Susan Prior's (@susanprior) first new fish record from Norfolk Island. In the past month alone she has recorded three new fish records for the island that I will be including the next time I update the checklist. A big thank you to Susan for her excellent observations! Thanks also to my Australian fish colleagues, Doug Hoese and Mark McGrouther (@markmcg) for their help with identification.

Susan's other recent new fish records are the sabre squirrelfish (Sargocentron spiniferum) and dusky wrasse (Halichoeres marginatus).

Posted by markmcg: Thanks for your excellent comment @francism.

Susan has made a terrific contribution to our knowledge of the fish fauna of Norfolk Island. She has found a total of eleven new fish records from the island (list below). For more details, see her blog post.

Banded sergeant - Abudefduf septemfasciatus
Wartylip mullet - Crenimugil crenilabis
Marbled parrotfish - Leptoscarus vaigiensis
Dot-and-dash Goatfish - Parupeneus barberinus
Bluebarred Parrotfish - Scarus ghobban
Palenose parrotfish - Scarus psittacus
Yellowtail barracuda - Sphyraena flavicauda
Hornpike Long Tom - Strongylura leiurus
Dusky wrasse - Halichoeres marginatus
Sabre squirrelfish - Sargocentron spiniferum
Black Blenny - Enchelyurus ater

June 20, 2026

From coral scar to aatuti farm

Aatuti are bold little algae farmers, but how does one of their farms begin? Over the past year, I have been following several coral patches as small white scars became algal footholds, then larger defended patches. I still cannot say what caused the first wounds, but the photo sequences show something fascinating: on a reef where algae is already gaining ground, even tiny changes on the coral surface can become part of a much bigger story.

June 15, 2026

Norfolk’s water quality – when action is reported as outcome

A recent Australian Government media release presents investment, monitoring and catchment works as progress on Norfolk Island’s water quality. Some of that work is useful, and some of it was badly needed. But activity is not the same as proven improvement. This post looks at Kingston sewerage, wetlands, cattle, acid sulfate soils, groundwater and reef health, and asks whether Emily Bay and Slaughter Bay are actually being better protected.

June 14, 2026

How surgeonfishes got their name

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.

May 28, 2026

A shrimp storm

While setting my research cams last week, I swam into what looked like an underwater snowstorm. It appeared to be the aftermath of a mass moulting event, with large numbers of tiny, translucent shrimp-like exoskeletons drifting together near the surface.

Kingston dredging: what happens when a reef does not fit the framework

This correspondence with DCCEEW is about more than one dredging proposal. It is about what happens when an ecologically distinctive place is assessed through standard tools that do not always make its most important values easy to see. I am publishing it here because that is something we need to be aware of, both on Norfolk Island and more broadly in Australia.

May 24, 2026

Kingston dredging: the project advances, the questions remain

Kingston dredging is edging closer, and the paper trail is growing. This post brings together earlier correspondence with the Department and the latest media release so readers can see what has been asked, what has been answered, and what still remains unclear about the project, its rationale, and the protections proposed for the reef.

May 17, 2026

The lime-green coral in Slaughter Bay – a 40-year paper trail

Green Mountain – the name I give this coral in my database – is a coral I’ve photographed for years as I swim past. Then I found its backstory in the Norfolk Island National Parks archives: a rough map, reused paper, a note in the margin – ‘still thriving’. That’s how baselines begin.

April 5, 2026

What Norfolk Island’s reef tells us about environmental blind spots

The Kingston dredging proposal on Norfolk Island raises a bigger question than dredging alone: how well do standard environmental assessment tools capture the real significance of a remote and unusual reef system like Norfolk Island’s?

March 30, 2026

Hammer coral time!

Hammer corals have unique tentacles that are large, fleshy, and tubular; these terminate in a ‘T’-shaped, hammer-head or anchor. Beneath all these softly waving tentacles is an extraordinary skeleton structure, which helps define them as a large polyp stony coral.

March 24, 2026

Norfolk Island’s fishes: drifters, residents and the ones still missing

Norfolk Island’s fish fauna reflects both connection and isolation. Some species may arrive from elsewhere as drifting larvae, some populations appear to persist locally, and some fishes known from islands on either side of Norfolk have still not been recorded here. This post looks at what old survey work, regional checklists and genetic studies suggest about that more complicated picture.