We recently received the following email message from Bradley Clarke-Wood, Conservation Ecologist, Regional Operations – Limestone Coast Region | National Parks & Wildlife Service Division, Department for Environment and Water: –
“As you may be aware, the Limestone Coast holds one of the few Thrombolite communities in Australia within Lake Hawdon South wetland complex. As you would appreciate, these life-forms have unique and distinct conservation needs but despite this, very little is known about them.
I was wondering if there was appetite within the Marine Life Society of South Australia Inc. to form an “interest group” with the mission of researching, monitoring, and conserving Thrombolite communities in the Limestone Coast? One approach could be to set up a friends of parks group: Home – Friends of Parks and Nature South Australia – regular grants (big and small) are available to friends of groups, which can support such activities.
There may be other models – very happy to discuss.
Kind regards,
Bradley Clarke-Wood”
The above details were posted to our Facebook page on 25th February, as follows: –
“Is there anyone interested in forming an “interest group” with the mission of researching, monitoring, and conserving Thrombolite communities in the Limestone Coast?
One approach could be to set up a friends of parks group. Regular grants (big and small) are available to friends of groups, which can support such activities.
The Limestone Coast holds one of the few Thrombolite communities in Australia within Lake Hawdon South wetland complex. These life-forms have unique and distinct conservation needs but, despite this, very little is known about them.”
Although both Faith and Peri Coleman commented on the post, there has not been anyone taking up the offer after the first week.
Here is the article that I wrote about thrombolites some 12 years ago: –
(I noticed a report in The Advertiser today (4th March 2025) saying that Lake Hawdon North has been cleared of native trees for a new wetland. 1100ha of native vegetation has been cleared. The $13.7m Lake Hawdon North wetlands plan is funded from a joint federal-state Healthy Coorong, Healthy Basin program. The Department of Environment and Water says that the project had the approval of the native vegetation council which had conducted rigorous environmental assessments.)
According to Wikipedia, “Lake Hawdon South Conservation Park is a protected area”.
The conservation park’s conservation significance is described as follows: –
“It supports biota of conservation significance including “17 vertebrate fauna species, seven plant species and three plant communities.”
Two plant communities are considered vulnerable at a state and regional level, being the “Baumea juncea / B. arthrophylla sedgeland on the western side of the lake and Gahnia filum / G. trifida sedgeland.”
It contains a field of microbial accretionary structures known as thrombolites which cover an area of 3.20 square kilometres (1.24 sq mi).
It contains about 100 native fauna species including the western grey kangaroo, wombat and bush rat, eight amphibian species and 15 reptile species including the state endangered glossy grass skink.
The conservation park is classified as an IUCN Category VI protected area.”
I found these images at https://vk5pas.org/2018/03/15/lake-hawdon-south-conservation-park-5cp-110-and-vkff-1045/ : –
(Source: https://vk5pas.org/2018/03/15/lake-hawdon-south-conservation-park-5cp-110-and-vkff-1045/)
I also found this image showing “The Drain L catchment including Lake Hawdon” at https://natureglenelg.org.au/wetland-restoration-and-an-elusive-little-fish/ : –
The Drain L catchment including Lake Hawdon
(Source: https://natureglenelg.org.au/wetland-restoration-and-an-elusive-little-fish/ )
A post by the Nature Glenelg Trust says, “Lake Hawdon South supports a suite of ecological values of national environmental significance including populations of Australasian bittern, little galaxias and a diverse and abundant community of migratory shorebirds. Other significant fauna includes glossy ibis, southern emu-wren and the enigmatic Australian mudfish, for which the wetland is a major stronghold. A unique formation of thrombolites also occupies approximately 300 ha of the reserve. The water regime is reliably seasonal, with a maximum depth of approximately 1 metre, and the salinity is fresh-brackish.”
Further details about the thrombolites can be found at https://natureglenelg.org.au/your-last-chance-for-a-new-and-unique-way-of-experiencing-a-wetland-treasure-from-our-region-the-thrombolites-of-lake-hawdon/ .
The web page includes this image by Ben Taylor: –
Thrombolites in Lake Hawdon South
(Photo taken by Ben Taylor)
(Source: https://natureglenelg.org.au/your-last-chance-for-a-new-and-unique-way-of-experiencing-a-wetland-treasure-from-our-region-the-thrombolites-of-lake-hawdon/ )
Ben Taylor, Senior Wetland Ecologist for Glenelg Nature Trust says that there are no visitor facilities at Lake Hawdon South Conservation Park and no access track to the thrombolites.