Species sighted at Witton Bluff & Christies Reef

by Steve Reynolds

As reported in My Early Diving Days , Witton Bluff is the high point on the coast between Port Noarlunga and Christies Beach. It is named after the 1839 wreck of the David Witton. I did my first sea snorkel there in January 1978. I returned there later that year with 10 scuba dives under my (weight) belt. I was back there again at the end of that year for my 15th scuba dive.

I wasn’t keeping any details about my dives there at this point, only the date, location and who my dive buddy was. This improved the following year. I returned to Witton Bluff for a MARIA (SA) dive on 21st October 1979. I had been appointed as the diving officer for the day. We had a dozen divers in the water that day, and some one dozen onlookers too.

Writing a dive report up was one of my duties as the day’s diving officer. A bonus of this was that my report was published in the Society’s new Journal. It is in the November 1979 issue of the MARIA Journal, Vol.1, No.2 under the title “MARIA Field Trip Report”.

The Journal’s editor seems to have added many of his own comments, and spellings too. My dive log had the correct spelling for Witton Bluff, Chris Douglass, Phill McPeake, etc.. yet the report in the Journal used spellings such as ‘Whitton Bluff’, ‘Chris Douglas’ and ‘Phil. McPeak’.

The editor had added some comments that I later had to explain were not mine. He also added the scientific names for some species sighted on the day. This is something that I would’ve been unable to do myself at that time. The bonus is that I can now report those sightings here: –

The rocks exposed by the low tide “were conspicuously covered by the long green cabbage weed Entromorpha (now Ulva/sea lettuce)”.

“Rock-crabs were everywhere”

Some of the feather stars were rather spectacular”

“A short spined variety of brown sea-urchin was common in the rockpools”

“a longer spined brown variety existed further out in 10 or so feet of water under ledges”

"there were abalones (Haliotis conicopora [now Haliotis rubra ssp. conicopora]and H. emmae [now Haliotis scalaris ssp. emmae],
chitons  (Aulacochiton crimolia, Ischnoradsia evanida [now Ischnochiton australis]) 
& Ischnochiton elongatus) shrimps, 
shark eggs, key-hole limpets, nudibranchs, worms, various small fish, and the molluscs 
Granata imbricate (imbricata) & Stomatella auricular"

“Denise found a green sea centipede about 2 inches long”

Much green and brown algae was seen during the dives, with “the very occasional tuft of Caulerpa (misspelled) cactoidesbrownii, as well as very small quantities of Caulerpa scallpelliformis . . . . but not much more in the way of submerged green algal sea-weeds”

“Particularly noticeable are the numerous gastropods Phasianotrochus eximus on the brown kelp, as well as the smaller darker variety P. bellulus”

“The brown kelp Eklonia was everywhere, so was the pink murex Lepsiella flindersi”

“On the blades of the sea grass Amphibolis antarctica we found Stenochiton cymodocealis . . . as well as Thalotia conica

I had noted in my log book having collected a coralfish, a nudibranch and some scallops. My (shared) dive report included reference to these, plus pencil urchins and caulerpa.

I didn’t return to the location again until 20th November 1983, accompanied by a handful of (now MLSSA) members. Unfortunately, I didn’t record any sightings at all. That was possibly the last time that I dived there. I did, however, return close to the spot this year with Dan Monceaux. I say ‘close’ because we entered the water from the southern end of Christies Beach to explore the shallow reef area just north of Witton Bluff. We are calling this site “Christies Reef”.

I mainly wanted to try out a new video light and flex-arm for my camera. I quickly wrote down in my log book that I had seen fish such as an eagle ray, juvenile bullseyes, brown-spotted wrasses, moonlighters, magpie perch, juvenile red mullet, a leatherjacket, sweep, crabs, Ceratosoma brevicaudatum nudibranch, hermit crabs, abalone, other molluscs, caulerpa, algae sea urchins and corals. I also recorded that Dan reported seeing more leatherjackets and eagle rays, and some strongies, (Dusky Morwong).

I thought that compiling a sighting list from the 1979 & 2018 dives might be reasonably easy, but scientific name changes have made it a bigger job than I had imagined. I have also had to go through the many photos that I took on my 2019 dive. The photos have increased the level of my sightings immensely.

Please forgive me if any of the following names are outdated, I have tried to use some of the names used by iNaturalist. I can now summarize the above mentioned sightings as follows: –

Species sighted at Witton Bluff in 1979

Phylum Arthropoda, Sub Phylum Crustacea, Class Malacostraca, Order Decapoda

Rock crabs


Phylum Echinodermata
Class Echinoidea -Sea urchins
A short spined variety of brown sea urchin (common in the rockpools)
A longer spined variety of brown sea urchin (under ledges in 3m depth of water or more)
(Slate?) pencil urchins (Goniocidaris tubaria?)

Class Crinoidea – Feather stars

Phylum Mollusca


Abalones – Haliotis rubra, Blacklip abalone & Haliotis scalaris ssp. emmae

Thalotia conica, conical top shell (on the blades of Amphibolis antarctica)
Granata imbricata, Tiled false ear shell
Stomatella auricular, false ear shell
Phasianotrochus eximius, kelp shell (on the brown kelp)
Phasianotrochus bellulus, necklace shell
Lepsiella flindersi, pink murex
Keyhole limpets – Family Fissurellidae (Vetigastropoda clade)


Polyplacophora – Chitons

                Aulacochiton crimolia 

                Ischnochiton australis

                Ischnochiton elongatus, the Lengthened chiton or Elongate Chiton

               Stenochiton cymodocealis (on the blades of the sea nymph wireweed Amphibolis antarctica)

Bivalvia – Scallops


Worms including a green sea centipede about 2 inches long

Truncate coralfish/Talma, Chelmonops truncatus
shark eggs
various small fish

Algae & seagrasses

Phylum Chlorophyta – much green algae including “the very occasional tuft of Caulerpa cactoides & Caulerpa brownii, as well as very small quantities of Caulerpa scallpelliformis

Ulva sea lettuce (on the rocks exposed by the low tide)

Phylum Phaeophyta – much brown algae. The brown kelp Eklonia was everywhere

Phylum Magnoliophyta – Amphibolis antarctica (wireweed)

Species sighted at Christies Reef in 2019


Southern eagle rays, Myliobatis tenuicaudatus

Bullseyes  – Pempherididae (juvenile)

Brown-spotted wrasses, Notolabrus parilus

Moonlighters, Tilodon sexfasciatus

Magpie perch, Cheilodactylus nigripes

Blue-spotted goatfish (juvenile), Upenichthys vlamingii


Banded sweep, Scorpis georgiana

Dusky Morwongs, Dactylophora nigricans

Smooth toadfish, Tetractenos glaber

Phylum Arthropoda, Sub Phylum Crustacea, Class Malacostraca, Order Decapoda


Hermit crabs

Phylum Mollusca


Blacklip abalone, Haliotis rubra

Murex, Pterochelus triformis

Common Warrener, Lunella undulata

Tulip shells, Pleuroploca australasiae

Short-tailed nudibranch, Ceratosoma brevicaudatum,


Scallops – Family Pectinidae

Algae & seagrasses

Phylum Chlorophyta –

Caulerpa species, including Sea Rimu, C. brownii, and C. cactoides

Sea lettuce, Ulva

Phylum Phaeophyta – including Common kelp, Ecklonia radiata

Phylum Rhodophyta – Red algae, including coralline algae – Order Corallinales

Phylum Magnoliophyta – seagrasses, including eel grasses, genus Zostera

Phylum Echinodermata

Class Echinoidea 

Western Pacific purple sea urchin, Heliocidaris erythrogramma

Class Asteroidea 

Common biscuit stars, Tosia australis

Velvet sea star, Petricia vernicina

Phylum Cnidaria – Plesiastea versipora, Green coral

Phylum Bryozoa – Bryozoans

Phylum Porifera – Sponges, including Cream honeycomb sponge, Holopsamma laminaefavosa

Phylum Chordata

Ascidians (solitary)

Botrylloides leachii, Ladder ascidian

The above lists are not thorough, or exhaustive, as there was no intention to compile such a list at the time of the dives. The only way to improve on these lists would be to return to the sites to record more sightings.

Society member Dan Monceaux has set up an iNaturalist project recording sightings at Christies Beach. The project aims to collect data about the biodiversity of the inshore reef between Witton Bluff and Christies Beach, and Horseshoe Reef. According to the project’s blog , more than 240 observations have been made and 84 species ID’d for the designated area as at 27/9/19. As stated, the area includes Horseshoe Reef, but the 300 metre swim out to Horseshoe Reef has limited the number of sightings made there.

I never got to dive at Horseshoe Reef myself. I only got to decide on one attempt that there was too much current there.

Many of the 84 species recorded by the project are listed above, but several of those were not sighted or recorded during the 1979 and 2019 dives. One should consider both the above lists in conjunction with the project list for a more complete picture of life in the area.

My thanks go to Dan Monceaux for setting up the iNat project for the area. All of the above underwater photos were taken by Steve Reynolds at Christies Reef in 2019.


By Steve Reynolds

Steve Reynolds is the current President of MLSSA and is a long-standing member of the Society. Steve is a keen diver, underwater explorer, photographer and is chief author of the Society's extensive back catalogue of newsletters and journals.

3 thought on “Species sighted at Witton Bluff & Christies Reef”
  1. Great work Steve… I’m glad you were able to find your notes from your early dives there and compare them with the current Christies Beach project on iNaturalist. The project continues to grow, with several new species added after my most recent snorkel out to Horseshoe Reef, including Haeckel’s jelly, Lion’s mane jelly and the nudibranch Verconia verconis.

  2. Dan,
    Was there any Common Kelp on Horseshoe Reef?
    I’ve not dived that Reef for decades and the main reason is that in the first half of my diving life I saw it deteriorate from a reef with at least a fair amount of Ecklonia radiata to a reef with essentially none. The last memory I have, which would be roughly 20 years ago looking through clear water from a friend’s boat on our way back to the ramp after a dive on Noarlunga tyre reef or thereabouts, is of a reef completely devoid of any canopy algae (no Kelp but also no fucoids eg Sargassum or Cystophora).I remember thinking what a shame, it would not even have warranted a quick snorkel.
    Of course I was comparing it with its far healthier state when I was a teenager, so many people snorkeling there now -mostly later generations- won’t realise how it once looked and how degraded it is now. I myself as a teenager was probably seeing it in an already significantly degraded state.
    So sad.
    David Muirhead

    1. Good news in part at least, Dave. The inshore wall of the reef has good Ecklonia cover, at least it did on my last snorkel out from the beach over a year ago. The shalloows/top surface does appear to be something of an urchin barren though, at least the southern quarter or so, as that’s the only part I’ve explored when swimming out from shore. I find it a rewarding snorkel on a calm day when the swim out isn’t impeded by surf.

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