Mallacoota Inlet and Gabo Island
At the far eastern tip of Victoria is a remote wilderness that few people have seen. It is Victoria’s Pacific rim, bathed in warm water from the tropical north and buffered by waves generated in the east, a stunning feature of the coastline.
Mallacoota Inlet, with its shimmering lakes, rivers, pristine forests and turquoise sea lapping quiet beaches, is an extraordinary part of Victoria’s coast. Gabo Island is equally prominent, supporting a highly diverse range of animals, including invertebrates, fish, whales, seals and significant sea birds such as the largest known colony of Little Penguins.
What are the key natural features of this area?
- Much of the coastline is formed by mobile sand dunes that are gradually shifting over the border into New South Wales. Bordering these dunes is a mixture of ancient pink granite and purple sandstone formed over 350 million years ago.
- The coast around Mallacoota is made of strongly folded sandstones, shales, slates and cherts. Boulder and cobble beaches and rocky shore platforms are common in the area. Spectacular jagged shore platforms intersected by gutters and rock stacks enhance the wild feel of Victoria’s wilderness coast. Small patches of sandy beach create bars across small lagoons at the mouth of creeks.
- Bastion Point is a prominent feature at Mallacoota. A low rocky reef backed by cliffs and bluffs form a somewhat sheltered cove with sandy beaches on either side of the point.
- A sandy dune-covered barrier often blocks the entrance to Mallacoota Inlet, with a tidal delta just inside the entrance. This delta has sandy spits and bars, as well as islands that support important saltmarshes. A sandy beach with grassy dunes extends from the entrance to Mallacoota Inlet. Freshwater lakes, Lake Barracoota and Lake Wau Wauka occur behind the dune system.
- Mallacoota Inlet is an important feeding and roosting area for birds. The area has important sandflat and saltmarsh habitat as well as estuary grass and lagoon habitats, and is of high conservation value.
- Vegetation on Gabo Island is stunted by salt, wind and harsh weather conditions. Trees include tea-tree and banksia. Tussock grass in amongst the granite boulders provide nesting habitat for Little Penguins and shearwaters.
- The reefs surrounding Gabo Island consist of areas of smooth, sloped bedrock, domed bommies with steep sides and boulder fields intersected with crevices. The reefs of both Gabo and Tullaberga Islands have large areas of sea urchin barrens, where long-spined urchins keep reef surfaces bare of seaweeds and inhabited instead by encrusting coralline algae. Gabo Island also has kelp habitat on the more exposed southern and eastern reefs. Patches of urchin barren habitat are also found around Cape Howe.
- From Telegraph Point to Cape Howe the coastline is dominated by high dunes with blowouts. The shore in this region is mostly sandy except for a small rocky outcrop at Iron Prince Reef, made up of tilted sandstone and shale. These rocks outcrop near the border at Cape Howe, forming the Iron Prince, the last reef in Victoria. A lot of the intertidal shore from Iron Prince Reef to Cape Howe is steeply sloping boulder and cobble beach. Woodland scrub and swamp habitat occurs behind the dune system of this region.
- Extensive deep reef habitat occurs offshore from Iron Prince and Cape Howe. The Iron Prince is composed of a series of rocky ledges and gutters that jut straight out into the sea. The ledges are covered in a dense forest of the brown seaweed Phyllospora that reaches over two metres in length. Beneath this thick, swirling canopy there are many smaller seaweeds, red sea-tulips, sponges, colourful seastars and large shells. Tiny brittle-stars, pill-bugs, and brightly-coloured worms nestle around some large sea-squirts.
- Off this section of the coast, the seafloor tilts steeply down into the deep-sea. In deeper water, where there is not enough light for the large brown seaweeds, the low sandstone reefs are covered with small patches of leafy red seaweeds and many attached animals. Sea-whips are common, arching gracefully up from the seafloor.
- This whole region is alive with a variety of fish, with an assortment of warm and cool water species. Purple Wrasse, Blue-Throated Wrasse and Herring Cale dart among the kelp. Large, disk-like sunfish are relatively frequent visitors, cruising slowly in the surface waters feeding on jellyfish.
- Gabo Island is home to both a penguin colony and a seabird rookery. It supports a highly diverse invertebrate community and a high diversity of fish species, and is important for several listed species including the White-bellied Sea-eagle, the Humpback Whale and the Southern Right Whale. Hundreds of humpback whales pass through the area on their annual migration between the tropics and Antarctic waters, sometimes followed by pods of Orcas.
- Gabo Island supports highly significant colonies of seabirds, such as shearwaters and the world’s largest known colony of Little Penguins. Birds of prey also regularly visit the island from the mainland and many other sea birds can be sighted out to sea depending on the time of year. Seals are often seen in a ‘raft’ off the point from the Light tower. Whales can be sighted as they migrate along the coastline during September and October.
- Other fish species you might include are the large, inquisitive, and charismatic Eastern Blue Groper Achoerodus viridis; the Black Sea-urchin Centrostephanus rodgersii, a common animal amongst the rocks in this area, they ‘glow’ an iridescent blue green; and Coralline algae Amphiroa anceps, with areas of reef at Cape Howe covered with patches of the small, upright, pink coralline seaweed like miniature forests.
- Other forms of coralline grow almost flat, resembling splashes of encrusted pink paint against the rocks. These encrusting corallines compete with each other for space, each one overgrowing the other. To keep themselves clean of other growth, they frequently shed their outer coating.
- There are some major threats to the area including shipping, fishing, climate change and inappropriate coastal development, for example the proposed development at Bastion Point.
Marine Protected Areas:
Cape Howe Marine National Park
Gabo Island Lighthouse Reserve
Cape Conran Coastal Park