Discover a 20-year wetland restoration success story on SA's Limestone Coast

Is a swamp something to be celebrated? In the movies, they’re all ogres, despair and perilous quicksand. Historically, swamps have been seen as problems for humans to solve: soggy land that needs draining to make way for 'progress' like farming and building.

Reframing our view of swamps

Over the last half century however, a rosier light has begun to dawn on swamps. Or as they’re slightly more sympathetically known, wetlands.

In 1971 the Ramsar Convention on Wetlands, an international treaty to protect wetlands, was signed in the city of Ramsar, Iran.

The Ramsar organisation spells out the values in its 2025 global wetlands outlook: “Wetlands offer unparalleled benefits to biodiversity, the climate, water resources and human health.

"They regulate floods, store carbon, purify water and support food security for billions of people.”

More than mosquito-infested sludge, then! So with that re-brand of ‘swamp’ in mind, discover Pick Swamp, a restored wet wonderland within Piccaninnie Ponds Conservation Park, south of Mount Gambier.

How does a freshwater swamp occur by the coast, without a river?

The Limestone Coast, as it’s known in this region, is actually just the edge of a deep shelf of limestone which continues far inland, underground. It began developing when the area was under the sea from around 40 million years ago.

Then around 15 million years ago, the sea retreated and its floor of sand, coral, shells and fish skeletons hardened into fossil-rich limestone.

Today, inland rainfall soaks through surface soil and into this porous rock.

The water creates distinctive features including sinkholes, caves and underground rivers in the limestone (known as a karst landscape). In a journey of 30 years or more, water seeps towards the sea.

The freshwater wells up to the surface near the coast in seasonal and permanent springs and wetlands.

These once covered around half of the Limestone Coast landscape, teeming with plant, animal, bird and water life.

Since the 1860s most of this land has been drained for farming.

Wetlands and all the biodiversity that relied upon them have dwindled to isolated pockets, about 5% of the original wetland area.

The good news? It’s not too late to make a difference. Pick Swamp is a living demonstration of how wetlands can rebound when water is returned.

From wetlands to cow paddock … and back again

Pick Swamp is now part of the Piccaninnie Ponds Conservation Park and its wetlands. But just 20 years ago the area was a flat, grassy cow paddock.

The land had been artificially dried out for decades. The clear, fresh groundwater welling up from the limestone was channelled straight out to sea.

In 2005 the South Australian Government purchased 230 hectares of farmland to extend the conservation park and return to nature.

Restoration works were planned and carried out by Department for Environment and Water staff with significant input from volunteers, and funding sourced from local, state and Australian government agencies.

Beginning in 2007, earthworks, levees and water control gates were engineered to allow the land to hold freshwater again.

Pick Swamp refilled. Fishways were constructed to let aquatic life travel to and from the sea.

Aquatic grasses and reeds re-established, mostly by themselves. Woodland vegetation around the swamp was replanted in massive efforts by government-funded and local volunteer groups.

Nature, nursed back to health, has taken over again

Today, two decades after the property purchase, Pick Swamp teems with life.

Around 25 species of native fish thrive, from little galaxias and thousands of southern pygmy perch to larger species such as congoli (freshwater flathead) and short-finned eels.

Stands of woodland, wet tea-tree shrublands and coastal scrub shelter birds, reptiles and native mammals including rakali, swamp wallaby, bush rat and swamp antechinus.

Claire Harding, Conservation Ecologist with National Parks and Wildlife Service, has been part of a team of DEW ecologists, university researchers and consultants monitoring the health of the swamp and Piccaninnie Ponds.

Claire said, “whilst there have been water quality and quantity concerns at Piccaninnie Ponds over recent years, Pick Swamp continues to support a huge amount of aquatic biodiversity, with the highly productive swamp likely acting to cycle some of the excess nutrients in the system. Pick Swamp has been very important over recent dry years, as a permanent water source that provides drought refuge for many waterbirds.”

Also part of the monitoring group, Lachlan Farrington, Senior Ecologist of Nature Glenelg Trust, said, “you can see the abundance of aquatic plants.

"That vegetation does a great job in treating any excess nutrients that might be coming in, which we’ve seen at other sites."

185 bird species spotted

Birdlife flocks to the wetland for food, water and shelter. Since restoration began, 185 bird species have been recorded here.

Brolgas, a vulnerable species in South Australia due to loss of wetland habitat, have returned. Magpie geese, once considered fully extinct in the region, congregate here daily in their thousands. It's sight to behold at sunrise.

Locals Bob Green and Jeff Campbell have been part of a volunteer group monitoring birds at Pick Swamp for Birdlife Australia, for almost 20 years.

Bob said, "it's been fantastic to be a part of seeing that journey from just the cow paddock that got wet occasionally to what is now regarded as a major restoration success."

The endangered Australasian bittern has been one of the area's great success stories.

Jeff said, "the Australasian bittern is a bird I’ve been very excited to see, and now we generally see those every time we go there. Magpie geese breed there in large numbers and there's at least a couple of breeding pairs of brolgas."

"It's a phenomenal site for Australasian bitterns, "Bob said, "and the highest number I've seen was 16 individual birds in one morning. From a global population estimate of only 1300, that's more than one per cent."

Wetlands fight climate change

Healthy wetlands like Pick Swamp are powerful carbon sinks. They're vital weapons in the fight against climate change.

Aquatic and swamp plant life is highly efficient at capturing carbon from the atmosphere.

When dead plant matter builds up under the right waterlogged conditions, the carbon is locked away for the long term, becoming saturated peat soil.

(Thought peat was only found in the Scottish highlands? Find out more here: What is peat? - International Peatland Society.)

Reinstating natural wetlands at the coast also helps stabilise local groundwater levels and buffer surrounding land, including farmland, against drought conditions.

A more resilient, balanced landscape is better able to sustain a range of activity for people and nature, into the future.

A Ramsar-listed wetland since 2012

The wetland of Piccaninnie Ponds Conservation Park was listed as a Wetland of International Importance under the Ramsar Convention in December 2012.

Now, just over two decades since the Pick Swamp land purchase extended the park, the thriving biodiversity here shows us what is possible when we work towards a landscape that can support us all.

Discover another wetland restoration just beginning on the Limestone Coast: Saving our springs: Karst springs and alkaline fens restoration | Engage Limestone Coast Landscape Board

Discover more about the Piccanninnie Ponds Conservation Park: 2019_piccaninnie_ponds-teacher_resource_pack_lowres.pdf

Special mention to Steve Clarke, Wetlands Conservation Ecologist, who passed away in 2018. Steve was instrumental in the restoration of Pick Swamp and leaves a legacy for generations.