Fauna
The diverse geology of the Sanctuary provides a variety of habitats including sponge gardens on the deeper reef, intertidal reef, rockpools, boulder fields and sandy beaches. The large brown kelps, Durvillea and Phyllospora are the dominant plants growing on the reef and on the large rocks within the Marine Sanctuary. The kelps provide shelter for a wide range of invertebrates present on the reef include sponges, hydrozoans, gorgonians, yellow zooanthids, stony coral, lace bryozoans, green and black lipped abalone, nudibranchs, rock lobsters, hermit crabs, mosaic sea star, feather stars and sea tulips. The shore rock platforms are covered in swathes of Neptune's Necklace, a brown algae that looks like strings of beads. The deeper rock pools are full of life including octopus, decorator crabs, chitons and schools of tiny silver fish. The offshore rocks are fringed by swirling Bull Kelp, which thrives in the breaking waves. Colourful sea-tulips and encrusting sponges grow on the rocks. Blue Throated Wrasse, Rosy Wrasse and Sea Sweep are common fish. Schools of Yellow-eyed Mullet swim by. There are Cat Sharks in the kelp and stingarees, skates and rays on the sand. Port Jackson Sharks can be seen resting in a sandy corral past Eagle Rock. These prehistoric-looking sharks with a crested head have rows of small pointed teeth that are used to crush pipis and other molluscs that they forage from the sand, as well as urchins and seastars from the reef. Johnsons Weedfish (Heteroclinus johnstoni) Although it is big mouthed, big eyed and the biggest weedfish in Australian waters, Johnsons Weedfish is still hard to detect in its natural habitat because it is perfectly camouflaged amongst the seaweeds of the kelp understorey. They are a seafloor predator and eat shrimp, crabs and small fish. Their prominent, branched nasal tentacles serve as an effective sensory aid in the wave turbulence. Johnsons Weedfish is only found in southern Australia in the waters around Tasmania and in between Kangaroo Island and Port Phillip Bay. Port Jackson Shark (Heterodontus portusjacksoni) Harmless, docile and gregarious in nature, this seafloor-dwelling shark is commonly seen nestled in groups under rocky ledges in Bunurong. At night Port Jackson sharks venture out and explore the reef, their flattened rows of pointed teeth and their strong jaws enabling them to crush reef animals such as marine snails, urchins, and crabs. Often these sharks will regroup in the same crevice as daylight approaches. Each October the females lay between 10 and 16 dark, corkscrew-shaped egg cases that they wedge into ledges with their mouths. You might be lucky enough to find one of these hatched egg cases on the beach. Geological, Hydrological and Landform Features The geology of this sanctuary is varied with a complex mixture of sandstone and basalt and incorporates a range of shore platforms, pools, subtidal fissures and boulder fields. Within the Marine Sanctuary two distinct rock types are easily observed. The oldest are the layers of basalt formed from eruptions of volcanoes during the Eocene period (36 million years ago). When this area was covered by the ocean during the Miocene (~15 million years ago) the yellow limestone which is a major feature of this section of the coast was formed. The cliffs are full of caves and ledges and the shore is beset with boulders. Offshore there are two large rocks: Eagle Rock, a tall volcanic stack capped by limestone and Table Rock, which has been levelled by the incessant waves.
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