Coochiemudlo Island: Weeds, biodiversity and biosecurity

By Angela Hoskins

National Biosecurity Week as on 25-31 August. Australia also dedicates a whole month — September — to biosecurity awareness! Five weeks of focus on what must be an important issue. Why?

Biosecurity plays a critical role in protecting our environment, agricultural industries, food supply, communities and overall economy — maintaining good lifestyles into the future, too.

North-east corner of Coochiemudlo Island in Moreton Bay, Queensland.

Islands are particularly at risk from biosecurity threats. On islands, populations of native species are usually smaller and confined to narrow habitats — a pest invasion could wipe out an entire species (Invasive Species Council). Imported red fire ants have been found on the island, and dealt with before the infestation got out of control, and ongoing vigilance is required. Cane toads are on the island, out-competing native species for food and habitat. Invasive weeds have steadily taken over areas of island’s Emerald Fringe and Melaleuca Wetlands and, if ignored, these weeds will continue to spread and impact island’s ecosystem and biodiversity of native species.

Welcome signage at the entrance to the Melaleuca Wetlands states:

Yura Oodjeroo Oodjeroo Dabil Jara nu

Welcome to the Melaleuca Wetlands

For thousands of years Quandamooka people have valued these wetlands. We have an ongoing connection to this special place through inherited responsibilities, traditional knowledge, shared stories and surviving cultural sites.

The spirit of Caring for Country continues.

This Oodjeroo Oodjeroo (Melaleuca) sanctuary is protected by the Ramsar Convention, an international treaty to conserve our most valuable wetlands through wise use and management.

By keeping to the pathway you are showing respect and helping to look after this fragile environment.

For thousands of years, Quandamooka people looked after and valued the Melaleuca Wetlands.

Back in 2015, a Weed Management Plan was commissioned for Coochiemudlo Island, but it was never implemented. Ten years on, the weeds have significantly worsened. It is not too late to put together another plan of action for the sections of the Emerald Fringe and the Melaleuca Wetlands where mother-in-law tongues, asparagus fern, Singapore daisy and many more weeds are taking hold.

Mother-in-law tongues, Singapore daisy and other weeds in the Melaleuca Wetlands, Innes Street, Coochiemudlo Island

View fullsize

Ageratum in the Melaleuca Wetlands, growing on the Elizabeth Street border. If you are viewing on a large screen, click the photo to see the spread of this species in the background, 20+ metres deeper into the Wetlands. Photo taken in September 2025.

Corky passion vine and asparagus fern on the western side of the Emerald Fringe.

A shared responsibility

The Biosecurity Plan for the Redlands Coast

The Redlands Coast Biosecurity Plan 2025-2030 includes a shared responsibility framework requiring efforts from all stakeholders. This includes RCC and the community.

Coochiemudlo Island has a long history of community groups and individual residents volunteering time and working towards managing invasive species on the island.

The Great Cane Toad Bust on Coochiemudlo Island is coordinated by island resident, Clare Levin. With help from island residents, hundreds of cane toads on the island are caught and composted during January.

Coochiemudlo Bushcare was formed in the 1990s. Since then, they have been steadfast with working towards managing the island’s natural environment through managing invasive weeds and regenerative plantings of native plants. RCC provides Bushcare with equipment, materials, training to support this group of volunteers.

Coochiemudlo Island Coastcare was formed in 2013 with a focus on island’s eastern shoreline. Much of their work includes erosion monitoring, managing the invasive weeds on the Emerald Fringe, and regenerative plantings of native grasses.

Coochiemudlo Native Nursery work on a voluntary basis to grow native plants for the island. They regularly donate plants to the island’s Bushcare and Coastcare groups, and Indigiscapes on the mainland.

Areas on the Emerald Fringe (north-west, west, and south-west of the island), and in the Melaleuca Wetlands, that have extensive invasive weed growth are outside of both Bushcare’s and Coastcare’s mandated work zones. Let’s hope that RCC can offer some practical guidance towards managing these areas.

All local government areas in Australia are obligated to have current biosecurity plans to manage invasive species. The aim is to protect not just the environment but also our economy and lifestyle into the future. The Redlands Coast Biosecurity Plan 2025-2030 was updated in June 2025.

The Plan covers invasive biosecurity matters across all land and waterways on Redlands Coast. It includes an extensive list of declared pests, or invasive species, in our local government area. Coochiemudlo Island isn’t specifically noted in the document, neither the SMBIs.

Declared pests of Coochiemudlo Island

Declared pests on the island as listed in the Redlands Coast Biosecurity Plan 2025-2030:

Animals: Cane toads

Imported red fire ants are not known to the be on the island at the time of writing. The community remains vigilant. An island resident reported an incidence of fire ants on her property in June 2025, and she put in place the required action put in place to eradicate them.

Plants: Arum lily; Asparugus fern; Corky passion vine; Glycine; Guinea grass; Leucaena; Morning glory; Mother of millions; Mother in law tongues; Ochna; Painted spurge; Purple succulent; Singapore daisy; Dutchman’s pipe; Velcro weed.

See photos of these invasive weeds on the Coochiemudlo Native Nursery website.

Responsibilities, education, and awareness about invasive species

Business Queensland has stated that everyone is obligated to take all reasonable and practical steps to minimise the risks associated with invasive pests.

The following photos of garden waste on the Emerald Fringe, and invasive weeds on both the Emerald Fringe and Melaleuca Wetlands, were taken in August 2025.

Actions to consider

No more dumping of garden waste onto public land

In our environment, many garden plants quickly spread when dumped in bush or public land (see the first photo below). Council operates a waste disposal depot on the island with a section allocated for green waste. We can also add garden weeds to the weekly wheely-bin pickup on the island.

Invasive weeds should be sealed in tough plastic bags.

Educating RCC’s outdoor workers and contractors

Council’s landscape workers and contractors would benefit from additional training to understand what are native plants, and what plants are invasive weeds. This training could lead to improved job satisfaction for outdoor workers on the Redlands Coast.

Maybe interested residents could be invited to attend this training, too?

Mother-in-law-tongues growing on the nature strip between Elizabeth Street and the walking path.

Image from Coochie Community Facebook post: Native grasses on the nature strip near the ferry terminal, planted by the island’s Native Nursery voluteers, inadvertently cut down by council workers. This action was not ill-intentioned. Awareness and guidance about the island, offered to workers, will be beneficial.

Community awareness about plants to avoid in our gardens

Learn to identify invasive weeds on the island. Many of us move to the island without much knowledge about invasive species. Excitement and enthusiasm about planting out our gardens can result in us buying or accepting plants that turn out to be pests — in our gardens and further afield when birds spread the seed.

Work out strategy for larger-scale management of invasive plants

In relation to managing larger areas of invasive weeds on public land, working out an action plan with RCC will be a good start. There is little or no practical guidance available on the RCC website about managing or eradicating invasive weeds on the Redlands Coast. It would be good if there was an online resource for the community to confidently be guided by considering the state of many sections of our Emerald Fringe and the Melaleuca Wetlands.

Could it be helpful to have a skip or bin on the island for sealed bags of weeded invasives to be dumped in? And from there, what would be the next part of the process?

Sunshine Coast Council has a page about invasive plant control options with information about solarization that states:

‘Solarisation uses the suns heat and black plastic cover to control invasive plants and reduce the seed bank in the soil. To solarise invasive plants cover them in thick black plastic and weigh it down on all sides or use pegs to keep the plastic down. The plastic will stop light reaching the plants which will stop them from being able to photosynthesise and will trap heat which will reduce the amount of seeds able to germinate in the soil. The process takes around 2 to 4 months depending on the weather. Factors such as rain and temperature will affect the success of solarisation. Solarisation is not usually effective for deep rooted plants as the soil temperature is usually only hot enough in the top couple of centimetres’ (Sunshine Coast Council).

Further reading and listening:

Audio

Who is responsible for solving the world’s problems – me or the System? (ABC RN: The Philosopher’s Zone, 15 August 2025)

Changing Australia: Tim Low and getting rid of invasive species (ABC RN Breakfast, 26 August 2025)

Articles

Queensland Government information about prohibitive invasive plants