In the middle of the Huon River, two low-lying sections of marshy land stretch for over 10 kilometres south of Huonville. Known as the Egg Islands, they were created by the accumulation of fine sediment in the river and are now considered the least disturbed estuarine depositional landform in Tasmania.
Keen to see more of the islands that we had only glimpsed from afar, a friend and I launched our kayaks from a boat ramp near Cradoc on the eastern side of the river. A few minutes of paddling and a favourable current took us the 100 or so metres across the river to the edge of the islands. We let the current push us downstream, staying close enough to be able to reach out and touch the sedges and grasses that dominate the marshy banks.
Before long we found what we were looking for – a 20-foot-wide canal cut through the width of the islands.
In the early years of European settlement in the Huon Valley, the hubs of activity centred around modern-day Wattle Grove, Cradoc, Cygnet and Franklin. Water travel across the river between these towns was made difficult by the location of the Egg Islands, and the natural channel that divides the north and south sections islands was too far north to be convenient. To solve the issue, convict labour was used to cut a canal between Cradoc and Franklin in 1838. It experienced such issues with silting that a new, deeper canal was commissioned in the 1880s. This laborious work took two alternating teams of horses and dredge almost a year to complete. Today, it is considered the oldest operational canal in Australia.
Navigating into the canal immediately brought respite from the strength and noise of the river current and our kayaks soon floated to a gently-turning rest. The sedges and rushes continued to blanket the banks here but now we were shaded on both sides by a canopy of thick melaleuca scrub and black gum woodland behind. Birdlife darted through the branches, and from our seats on the water we peered upwards, trying to identify them from among the dozens of native bird species that forage and nest on the islands.
As we paddled slowly through the canal, we kept watch for signs of the native mammals that have thrived here in the absence of feral cats, including pademelons, potoroos and brown and eastern-barred bandicoots. We kept an even closer watch for the tiger snakes for which the islands are famous. If they were there, they were well camouflaged.
It didn’t take long to reach the end of the canal and be able to look across the river to the walking paths, sports oval and rowing club on the Franklin waterfront. As we considered the township before us, with the knowledge of another not far behind us, we could understand why the canal played such an integral role in connecting the early Huon settlements. Their central location also meant the islands were used for a variety of activities throughout the 19th and 20th centuries including apple and pear orchards, the growing of vegetables, grazing of cattle and sheep, harvesting timber, duck hunting and greyhound training. The ground was so swampy that drains needed to be dug by hand to improve the conditions, and most agriculture on the islands had been abandoned by the 1950s. Today, the main evidence of human impact on the islands is the canal. We turned and began our slow paddle back through, brushing near the native grasses on the banks that trail in the water like skirts and soften what must have once been a raw scar in the landscape.
In the years since the islands were used for human activities, they have regained much of their original natural value. They now host relatively intact vegetation communities, including large remnant forests of endangered black gum, and provide habitat for a range of threatened animal species, including the swift parrot, the grey goshawk, the Australasian bittern, the masked owl and the wedge-tailed eagle. The islands have been recognized as one of the most important breeding grounds in Tasmania for birds like the black swan, swamp harrier and chestnut teal.
These natural values mean that almost the entire 443 hectares of Egg Islands is now protected, most of it within the Egg Islands Conservation Area, and managed by the Tasmanian Parks and Wildlife Service. About 136 hectares is owned and managed by the Tasmanian Land Conservancy (TLC). When it bought the land in 2008, the TLC identified a number of weeds as key threats to the natural values of the island, including Spanish heath. A decade of control efforts means that the bulk of this declared weed has been removed and the native vegetation is re-establishing. The TLC is now working to treat introduced flax on the islands.
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As we floated back through the canal, I slowed to take in the stands of tall black gum alongside us. I had been too busy failing to identify bird species and spot nocturnal mammals on our first pass through here to appreciate the vegetation. Prior to European colonisation, black gum forests extended throughout Tasmania and supported a rich diversity of native wildlife. This includes the now-endangered swift parrot, which relies on black gum flowers as a primary food source during the breeding season. However, Tasmanian black gum forests have been cleared extensively for agriculture and urban use, with only about 5 per cent of those original forests remaining today. These tall, silent sentinels watching us float through the canal are part of the largest remnant black gum community in south-east Tasmania. I smiled to think of these two friends, the grand black gum and the tiny swift parrot, finding a refuge from the serious threats that surround them both in this little-known but critical outpost.
The exit into the wide Huon River approached, and I looked back one last time to take in the calm of the canal, before turning and ploughing into the current, heading for home.
Grace Heathcote is a Tasmanian writer. With a background in ecology and conservation. She has worked throughout Australia but has a soft spot for all things Tasmanian. Her writing has been published nationally, including in The Guardian, and her academic publications can be found in peer-reviewed journals such as Conservation Biology and Wildlife Research.