Marine Life

The well-lit surfaces of South Australia's natural reefs are generally covered with various types of kelp forest, such as the giant kelps of the southeast. Under the forest canopy lies an unparalleled diversity of other brown, red and green plant-like algae (more than a thousand different species), particularly in deeper and more exposed reefs. Most of these are comfortably within recreational diving limits.

You'll find a diversity of crustaceans, shellfish and starfish within these forests - rarely found anywhere other than southern Australia. Rocky reefs are often supported by adjacent habitats such as seagrass beds that are ecologically important and offer a nursery habitat for other species that visit the reefs. 

Several hundred fish and other swimming species, most of which are unique to Southern Australia, are closely associated with the various habitats described above.  Apart from iconic species such as Australian Sea Lions, Seadragons, Giant Australian Cuttlefish and Great White Sharks, there are many other charismatic or visually appealing species, including the Blue Groper, Blue Devil, Harlequin Fish, Fiddler Ray and Stripped Pyjama Squid.

Australian Sea-lion
Australian Sea-lions differ from 'true sea-lion' by having external ears and propelling themselves through water with their front flippers, as well as being more agile on land. There are just 12,000 which makes them one of the world's rarest seal species. Two-thirds of their population make their home in South Australian waters allowing divers many chances to see these friendly marine mammals in the water, particularly on Kangaroo Island, Eyre Peninsula and southern Yorke Peninsula. A well-established operation at Baird Bay on the Eyre Peninsula conducts regular wildlife tours, including in-water sea-lion viewing.

The natural curiosity of sea-lions commonly leads them swim extremely close to divers. Try a somersault, and the sea-lions will often show you how to do it better! Make sure that your fins are firmly strapped on - removing them from your feet is a game they have been known to play. The experience is best if you leave them in control of the interaction, make no sudden movements - and of course do not reach out and touch them.

Leafy and Weedy Seadragons
The Leafy and Weedy Seadragon, which are related to the seahorse family, are found only in southern Australian waters. They are fascinating in both appearance and behaviour. 

Both species have leaf-like appendages on their heads and bodies. This adaptation helps them to take on the appearance of swaying seaweed, making them difficult to see in the ocean. Seadragons have male mothers - although the female develops the eggs they transfer them to the father where they are fertilised. The father incubates the eggs for four to eight weeks before they hatch. Seadragons are able to change colour depending on age, diet, location and even stress levels.

South Australia exists as the central habitat for these two rare marine creatures, and the Leafy Seadragon, which is afforded some protection, is South Australia's marine emblem. Kangaroo Island and the Fleurieu Peninsula, particularly the Rapid Bay Jetty, are the perfect locations to find them. Seadragons inhabit rocky reefs, seaweed beds, seagrass meadows and structures colonised by seaweed. They feed on plankton, larval fishes and mysid shrimp.

'Leafies' grow to around 30cm long. They have numerous, branching leafy appendages. Adults are usually yellow brown in colour with thin pale dark edged bands. It is possible to identify individual Leafy Seadragons from their distinctive facial markings. 'Weedies' are larger, growing to about 46cm in length and have fewer and smaller leaf-like appendages that occurring singularly or in pairs along the body. Adults are usually reddish in colour with yellow spots and blue-purple bars.

The alert diver might also notice a diversity of related pipefish and pipehorse species! In order to protect these fragile creatures, please ensure that you observe the code of conduct called Diving with Dragons.

Sharks
The Great White Shark is an icon of South Australian waters. Diving with them has been described as the career highlight of many divers and photographers.

The Great White averages four metres in length although they have been recorded up to seven metres in length and weighing 3200 kilograms. Young Great White Sharks eat fish, rays, and other sharks while adults eat larger prey, including sea lions and seals, small toothed whales and sea turtles. Since the 1970s cage diving has provided the opportunity for safe diving with these spectacular creatures. It is available in the waters around the North and South Neptune Islands and Dangerous Reef off the Southern Eyre Peninsula.

Great White Shark diving out of Port Lincoln is available during most of the year. At times (when Southern Blue Fin Tuna are being towed) there will also be opportunities to see other large deep sea sharks that one would not normally see, such as makos and blue sharks. Great White Shark diving is recommended only with a recognised professional.

Giant Australian Cuttlefish
Described as the Chameleons of the Sea, cuttlefish are fascinating creatures. The Australian Giant Cuttlefish is no exception. Cuttlefish use thousands of complex structures embedded in their skin to produce countless different patterns and colours used for mating displays and camouflage.

Cuttlefish have another remarkable means of camouflage. They are able to change shape and texture in order to imitate rock, sand or weed. Should both these tricks fail, the cuttlefish can expel a cloud of black ink and escape in the concealing murk.

Whyalla, on the Eyre Peninsula, is known as the Cuttlefish Capital of the World. Each year from May to August thousands of giant cuttlefish migrate to breed at the reef areas around Black Point and Point Lowly.  They are attracted to this area, as they need a hard rocky surface on to which to attach their eggs. The low rocky reef areas at Black Point and Point Lowly are the only locations of their type on either side of the Upper Spencer Gulf.

The event has been recognised by Australian and international scientists as one of the most significant and spectacular naturally occurring events in Australian marine waters. Cumulations of Cuttlefish in these numbers occur nowhere else in the world.