Australia - Dive sites for opisthobranchs

Find participant's notes on dive sites in Australia which they find particularly good for sea slugs.

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Gold Coast Seaway - Best Australian City Dive Site ?

August 4, 2006
From: Ian Banks

I consider the Gold Coast Seaway is by far the best dive site in any Australian City. Those of us who have travelled the world diving in exotic locations appreciate the fact that very few locations have this level of diversity and abundance of sea life in an area so easily accessible 365 days a year.

One measure of this is not just the incredible diversity of the fish that inhabit the Gold Coast Seaway but their abundance, even when compared with some sites on the Great Barrier Reef.

The area known as The Sand Pipe has become a safe haven for thousands of fish including big eye trevally, mulloway, luderick and groper. Eagle rays are regularly observed out on the sand pipe, and at night they can be observed feeding on the ascidians. The fish don't feed while they 'hang-out' at the Pipe. They just get serviced by the local cleaner fish in their unique 'Seaway Sanctuary'.

The Gold Coast Seaway is accessible in all weather conditions including times when weather and sea conditions prevent boats from travelling out to the offshore dive sites and it is too rough for the beach front and near shore dive sites. There is parking 10 metres from entry point and off shore boats are not required as the site is in protected waters.

Water Temperature ranges between 27°C maximum in summer and a 19°C minimum in winter. Being an estuary entrance, the best time to dive is on the top of the high tide when the current is least and the water is clearest.Water clarity varies depending mainly on wind direction. When the prevailing wind, from the South-East, is blowing the visibility is usually 10 to 20 metres. Sea conditions very rarely drop the visibility below 10 metres. When the wind direction is from the North to North-East the visibility usually drops to less than 10 metres regardless of sea conditions.

The site caters for all levels of diving ability - Close to the wall is a popular location for teaching beginners and conducting introductory dives. The sand gradually drops to 8m then to 11m and reaches a maximum depth of 15m near the centre of the Seaway.

For the advanced divers the drift and night diving can be excellent and The Seaway is a photographer's paradise.

The Gold Coast Seaway can be divided into 4 main areas.
South Wall - The ultimate area is the South Wall which is usually entered from the shore at the Short Pipe where a cement slab leads to the waters edge. 40 metres east of here is the Sand Pipe which traverses the sea way. Between these two pipes and out along the Sand Pipe is the greatest display of marine biodiversity in one location in any Australian city.

North Wall - Normally dived at the entrance on the eastern end, this area is great for observing schools of pelagic fish which pass along the coast. On the outside of this wall is the only area that you are likely to see whaler sharks. Here you will find plenty of wobbegong sharks, but interestingly it is much harder to find them inside The Seaway. This area requires boat access and is more suited to an advanced diver due to the currents and depths of approximately 19m.

South-West Wall - This is a great starting point for the timid diver. A sandy beach entry with a gradual decline to 5 metres. Following along the wall northwards there are plenty of "muck diving" critters to be found as the current is considerably less than in the main Seaway. This is where sea horses and anemone fish have been located.

Wave Break Island - Constructed on the inside of the Seaway to prevent storm waves entering the broadwater, this island's isolated sandy beach dips gently to 11 metres alongside a rocky wall producing an excellent protected site for introductory dives, scuba lessons and snorkelling. There are lots of small colourful fish around the wall and it is a great "muck dive" location. In fact this is the only area where pipefish are consistently found on the Gold Coast.

Nudibranchs are observed at each of these sites.

For more information, photos, video clips and maps please visit:

Ian Banks.

Banks, I.W., 2006 (Aug 4) Gold Coast Seaway - Best Australian City Dive Site ?. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from

Thanks Ian,

We don't have much in the way of good dive site information on the Forum, but I am happy to include informative accounts if participants wish to provide them. But please keep 'best', and similar superlatives, to a minimum.

Best wishes,
Bill Rudman

Rudman, W.B., 2006 (Aug 4). Comment on Gold Coast Seaway - Best Australian City Dive Site ? by Ian Banks. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from

Notes from Mornington Peninsula, Victoria

January 18, 1999
From: Jane Breidahl

Hello again Bill. Thank you for replying to my question about Spurilla australis - I'm delighted that we found the heart! I have a few more 'finds' to mention especially since I can't seem to find any of them on your species list. Under Mornington pier in 9m of water at 8.45am on Saturday, I found four of the nudibranch Phyllodesmium serratum. I'm quite sure that the identification is correct as the description in Shepherd is spot on. On January 12th under St Leonards Pier, I found Madrella sanguinea - a tiny dot of a thing on Pachydictyon paniculatum. (Again, I think that's right - it's pretty hard to get the seaweeds correctI find) We've seen Madrella before, but isn't it the most spectacular thing under a microscope! My latest find is not really identified. Under Mornington Pier on one of the fine brown seaweeds, I noticed lots of very tiny little orange dots. I think they might be a sacoglossan - they look very like Midorigai australis but are the wrong colour. Can you help here?
Kind regards,
Jane Breidahl

Breidahl, J., 1999 (Jan 18) Notes from Mornington Peninsula, Victoria. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from

Dear Jane,
Thanks for your notes. I'll put pictures of the species you mention on the site as soon as I get a chance. I'm afraid your little orange spots are a bit difficult to identify. Did they have a shell like Midorigai?
Perhaps you can get your photographer friend to take some photos.
Bill Rudman.