Hills & Fleurieu
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Seadragons

Seadragons are delicate fishes that can easily be injured. Never touch or chase a seadragon. If you are lucky enough to see one, please respect its space, and try to stay at least two metres away from it. When filming or photographing, allow the seadragon to move at its own pace.

Our southern seas host a wealth of wildlife with many species found nowhere else. South Australia’s marine emblem, the Leafy Seadragon (Phycodurus eques), and the Common or Weedy Seadragon (Phyllopteryx taeniolatus) can be found on reefs off our Fleurieu coasts.

Leafy Seadragon Photo: Carl Charter
Leafy Seadragon (Phycodurus eques). Photo: Carl Charter

Community monitoring of seadragons at Rapid Bay, involving photographing and identifying individual dragons, has been provided with some support by the SA Department for Environment and Water since 2013. Volunteer divers, associated with South Australian Conservation Research Divers, have monitored the population under the Rapid Bay old jetty since 2013, and the project is now expanding to other areas of the State.

What will you find in the dragon’s lair?

Tube-mouthed suckers

Along with seahorses and pipefish, seadragons belong to the scientific family Syngnathidae, a Latin name meaning 'fused jaw'. This relates to the tube-snouted mouth of these fishes. Syngnathid fish also have bony plates surrounding their bodies, rather than the typical scales of fishes.

Swaying in the seaweed

Seadragons resemble swaying pieces of macroalgae or seaweed, which can make them difficult to find in their natural habitat of rocky reefs with brown algae (seaweed), or seagrass meadows. Some jetties provide important dragon habitat too. Seadragons feed on plankton, larval fishes and small shrimp-like crustaceans called mysids, sucking up their prey with their small mouths.

Co-parenting with a twist

Seadragons, like seahorses, have unusual breeding habits. Once paired up, the male and female tend to stay close together, and research is being undertaken to determine for how long. The female develops orange-coloured eggs in her lower abdominal cavity and, during a breeding ritual involving the movement of the pair up towards the sea surface, the female transfers the eggs to a soft and swollen patch of skin under the male's tail. As the male receives the eggs, the soft skin hardens around the eggs to form cup-like structures, and the eggs are fertilised. Mature males can carry around 250-300 eggs per brood. Based on photographs of known individuals, some male seadragons carry two broods per season.

Diving with dragons

If you are planning a dive and hoping to see Leafy or Weedy seadragons, please read the Code of Conduct. This code describes what you should and shouldn't do around seadragons, so as not to harm them or their habitat. It also includes tips for taking better photographs of them.

Citizen science in the sea

Want to help with seadragon research and conservation? Become a citizen scientist! Collecting information about this little-known species can help determine where they live, what their habitat requirements are, when they breed (and how often), whether or not there are changes over time to individuals, groups and their habitat, and why those changes might have happened. How do you take part? Each seadragon has unique markings on the face, head and leafy appendages, which can help identify them.

If you take any seadragon photos in South Australia, they can be uploaded to the citizen science portal iNaturalist. The managers of DragonSearch South Australia can then find your records, and invite you to the project. Once your iNaturalist account is linked to the Dragon Search South Australia project page, you’ll be able to automatically add your records to the project by clicking the Projects box on your upload page.

Rapid Bay dragons

Rapid Bay is a well-known site for viewing seadragons; however, there are concerns over potential disturbance from increasing numbers of visitors to this and other sites. Some of the Rapid Bay seadragons are ‘jetty residents’ and have lived in the area for many years. One seadragon, called 'Wishbone', has been recorded for more than seven years. It is likely that seadragons live for around 10 years in the wild, possibly longer. At certain times of the year the dragons may move further offshore but they seem to return back to the same sites each year.

To keep these and other seadragons safe, the code of conduct was updated. The original version of this code was jointly created by community and government when citizen science project Dragon Search was first developed during the late 1990s.

Dragon search

Prior to recent monitoring, a large-scale community-based survey of seadragons ran across southern Australia for over 10 years. This project advocated for greater protection of seadragon habitat and populations, and a national data base on sightings in Australia was developed. Although the original Dragon Search is no longer active, sightings within SA are still being encouraged via the Dragon Search South Australia project on the iNaturalist portal described above. Over time, the photos and associated data will be used to monitor populations at various sites across South Australia, just as such information was used for the Rapid Bay jetty population during the past decade. The DragonSearch South Australia data will also be shared with a new international initiative, SeadragonSearch, run jointly by Scripps Institution of Oceanography and the Western Australian Museum, with partner organizations, groups and individuals in each state. SeadragonSearch is seeking to identify individuals by using artificial intelligence to process photos.

Go on an underwater adventure

While the best way to observe them is by SCUBA diving, seadragons can sometimes also be seen when snorkeling in shallower coastal waters. If you want to explore the underwater world but do not have much snorkeling experience, check out Experiencing Marine Sanctuaries. This not-for-profit program, supported by the National Parks and Wildlife Service South Australia, provides guided community snorkel and underwater virtual reality adventures throughout the year.

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