Scourge purge

How a group of volunteers went into the wilderness and did what the authorities said could not be done


photographer JON MARSDEN-SMEDLEY


In July 2023, my eco-anxiety was triggered by one of Hobart’s warmest winters on record. Every morning I’d look up optimistically to kunanyi, waiting for the dusting of snow that wouldn’t come. The lack of snowfall being a sign of bigger problems, I decided to shake off anxiety and malaise in favour of proactivity. I signed up to volunteer for the Wilderness Society.

During the first meeting I attended, a campaigner put me in touch with Dr Jon Marsden-Smedley, an environmental scientist and advocate whose achievements tell us that hope is not yet lost, and that passionate individuals have the power to make enormous contributions to the environment.

Dr Marsden-Smedley has been drawn to the ancient wilderness of Tasmania’s remote south-west since the 1970s. With large areas accessible only by foot, boat or plane, he described the ragged mountain ridges, button grass plains, deep harbours and long stretches of windswept coastline, and the many unique plants and wildlife, of the south-west wilderness as “one of the last great environmental strongholds of Tasmania, and the world”.

“It’s one of the most amazing wilderness areas worldwide. The area south of Strahan, between Cape Sorrell and Port Davey, is almost unvisited. Aside from a few cruise ships going up the river, a couple of boats coming in Port Davey, the usage by humans is minimal. I’ve spent almost my entire career involved in the management of this area. For about 20 years I was the bushfire management and research officer for the Tasmanian Wilderness World Heritage Area, so this was effectively my office. But I’ve also hiked it recreationally, going for about two to six weeks at a time.”

Marsden-Smedley has spent a cumulative total of more than two years trekking and camping around the south-west wilderness, chasing the remote experience that comes from hiking days on end not seeing another person, the serenity of having a beach to himself, save for a circling white-bellied sea eagle, watching a red sun slip into the water on the horizon.

Unfortunately, not all the South-West region is protected and as a result faces threats, including an influx of invasive weeds, choking out native flora and disrupting the sensitive ecosystem.

In the early 2000s, Jon Marsden-Smedley identified an increase in the numbers of invasive weeds, including marram grass and a flowering plant called sea spurge. “Over the years I noticed less and less signs of human visitors. Campsites became overgrown. But what didn’t disappear were the weeds,” he said.

Sea spurge invaded Western Australia and South Australia in the early part of the 20th century, likely via ship ballast water. It quickly spread beyond control, and is now present across the southern, south-western and south-east coastlines of mainland Australia as well as much of Tasmania.

Sea spurge causes considerable damage to the environment due to its ability to change the structure of beach and dune environments and displace native plants, including shrublands, herbfields and grasslands, as well as shorebird nesting sites and marsupial feeding areas. It also releases a toxic sap which can cause skin and eye irritation to humans and animals.

Marsden-Smedley alerted authorities to the increasing threat of sea spurge and marram grass in the south-west wilderness, but was told to give up: the problem was too extensive, and it would be problematic to attempt eradication of weeds in such a remote, inaccessible region. Dr Jon Marsden-Smedley considered the challenge, and ignored the advice to give up.

He took leave from his post-doctoral research position, and spent six weeks mapping areas of affected coastline: identifying access sites, campsites and weed management sites between Cape Sorrell and Cockle Creek. With the assistance of experienced remote area weed management people from the Blue Mountains in New South Wales, the volunteer group Sea Spurge Remote Area Teams (SPRATS) was formed. Since then, SPRATS members spent summers progressively weeding the Tasmanian south-west.

Eventually, SPRATS proved its value, garnering the support of state and federal governments. Tasmanian Parks and Wildlife and, more recently, CSIRO, have come on board. Thanks to Marsden-Smedley and up to 70 volunteers per year, more than 14 million plants across about 850 kilometres of coastline have been removed. Specifically, SPRATS has reduced the number of invasive weeds by more than 99 per cent, allowing significant recovery of native vegetation.

“The biggest success of our program is that we helped minimise the impact on the environment,” Marsden-Smedley says.

“We got this under control before shorebird levels started to drop significantly. It is always easier to protect the environment than to rehabilitate.”

Re-invasion from ocean-dispersed seeds poses a continuing threat to the goal of permanent eradication, so a group of about 25 volunteers is still required for ongoing low-level maintenance each summer. Marsden-Smedley hopes this time-consuming work can be reduced with the introduction of bio-control methods supported by CSIRO. Specifically, CSIRO is trialling release of Venturia paralias, a fungus which targets sea spurge, slowly killing the stem of invasive plants without infecting or spreading to native species.

Healthy, biodiverse ecosystems are vital to life on Earth, and play a particularly important role in south-west Tasmania. Well-functioning biospheres help mitigate climate change, and are more resilient against its effects. Rich ecosystems are also a source of medicinal plants and food, and underpin clean air and water systems. Eco-tourism depends largely on the appeal of nature at its most natural; abundant local flora and fauna, springs, waterfalls and unspoiled wilderness afforded through maintenance of a balanced ecosystem.

Tasmania’s south-west has been identified as a critical environment for shore-nesting and feeding birds, including the hooded plover, pied oystercatcher, sooty oystercatcher and orange-bellied parrot. Further, according to Marsden-Smedley, the large natural land area makes south-west Tasmania a logical candidate for traditional aboriginal land management practices.

What can you do to help?

For any reader struggling with the weight of eco-anxiety, as I was, here are some ways to make a positive difference:

  • Sign up to volunteer with environmental protection groups, such as the Wilderness Society
  • Register your interest to volunteer for SPRATS by emailing sprats.tas@gmail.com
  • Take your voting power seriously by researching the environmental policies of political candidates and parties

For more information

DPIPWE-Sea-Spurge-Guidelines.pdf (nre.tas.gov.au)

Southwest National Park | Parks & Wildlife Service Tasmania


Helena Gjone is an Australian-based, Norwegian-born writer with a background in psychology, dance and acting. She has had fiction published in short story anthologies such as Talent Implied and non-fiction published in media outlets including The Conversation and Dancetrain magazine. She is currently completing a PhD in creative writing, and working on her first novel.

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