Home » Ecosystems » In it for the long term – the Sandy Cape Lighthouse Weeding Program

In it for the long term – the Sandy Cape Lighthouse Weeding Program

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Lighthouse keepers manned Sandy Cape Lighthouse between 1870 and 1997. Like many lighthouses in remote locations, supplies came in, but nothing left the site, with rubbish dumped ‘over the hill.’  With only tank water, hardy plants were introduced by keepers. Many of these survived and escaped, spreading out over 1Km radius.

The historical Sandy Cape Lighthouse, K’gari constructed 1869 –1870

In 1997, Queensland Parks and Wildlife Service commenced a program to eradicate the garden escapees.  In 2008, the last ranger was withdrawn from Sandy Cape, and in 2007, a volunteer weeding program officially started. The partnership includes Sandy Cape Lighthouse Conservation Association (including Volunteer Caretakers Sandy Cape Lighthouse), Lower Mary River Land and Catchment Care Group (Landcare) and Park Rangers from QPWS.

Weeds identified at the site were prioritised based on their potential to be eradicated (prevented from flowering), and their significance as an environmental weed (ability to form monocultures, destroy native species or alter natural vegetation type). Based on this, the program initially focussed on four priority species – climbing asparagus fern, Easter cassia, green panic and sisal. Green panic, in particular, is very difficult to control as it can emerge and set seeds within six weeks. 

Other weeds are removed if time allows. Mother-in-law’s tongue, ground asparagus, Madeira vine, and Gloriosa lily have also been reduced to low numbers. In 2017, progress enabled volunteers to add coral berry (which can cover large areas preventing trees from emerging), mother-of-millions, corky passion vine, Mossman River grass (burr) and crow’s foot grass to targeted weeds. 

One advantage of Sandy Cape over other sites on K’gari is that it only has single tenure, making it far easier to coordinate management. QPWS has mapped the weeds, with most located in six valley floors. These have been subdivided into 96 work blocks that have all been geo-referenced and named. 

Blocks are systematically monitored and weeded by the volunteers.  All 96 work blocks are listed on sheets on a pinboard in the volunteer accommodation. When volunteers finish a block, they record the month and year beside the block name. Incoming volunteers then know which blocks were recently weeded and which are due to be done.

Effort has to be commensurate with the scale of the problem. Project Coordinator, Don Bradley with sisal hemp at Sandy Cape (Photo: Lesley Bradley)

Different coloured tape is used for colour coding, with outlier weed sites marked with flagging tape and a GPS location. Volunteers send their weeding report to the project coordinator with the block number, weed species, method of weeding (manual, chemical) and the number of weeds treated or removed. The coordinator records all data on QPWS forms before they are forwarded to the Ranger in Charge (RIC). Data is compared between years to track progress with an annual report sent to the RIC. 

Other than the program’s evident progress, achievements have included increasing awareness of weeds and their significance amongst the Sandy Cape volunteers. This has been enhanced by gathering weed samples (preserved in a folder) and general information posters. 

After 13 years, considerable progress has been made, but the program highlights the difficulty of eradication in remote locations and the need for a systematic approach. Progress has only been made with the dedication of the partners and with thousands of hours of volunteer effort. In 2019 alone, 14 volunteers contributed 625 hours to the program.

Weed management effort also has to be sustained over a very long time. Volunteers are still finding new weeds or pop-ups at the site such as flannel weed and red natal grass, and new areas where weeds were previously not mapped. 

The table below represents the total number of weeds detected (per species) during the 2019 calendar year and historically high numbers (scale) since the program commenced.

SpeciesHistorical High Number/ScaleCurrent Number/Scale
Climbing asparagus fern12,649374
Easter cassia6022
Sisal hemp2,9153
Green panic1,21335 (est.)
Madeira vine850
Mother-of-millions1,000s1,000s
Mother in law’s tongue5570
Coral berry10,000s10,000s
Corky passion vine1,000s1,000s
Mossman River grass/burr10,000s100s
Crow’s foot10,000s100s

The project represents a considerable commitment by volunteers. Their effort will need to be sustained at the current level for at least the next decade (until weed seed banks have been exhausted) and the team can step back to monitoring and detection of new incursions. 

When lighthouse keepers manned their stations to protect mariners and ships at sea, little did they know the weed legacy that they would leave behind. A footprint that one day would bring people back to their lighthouses to restore the natural integrity of the island that they called home. 

Article developed by Sue Sargent in conjunction with Lower Mary River Land and Catchment Care Group


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