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Southern Fleurieu

Water:  Containing new aquatic weeds

High Priority

What is this issue

New and emerging weeds (such as spiny rush, Rhodes grass) affecting aquatic habitat including swamps.

Impacts of the issue

  • Competition with native flora
  • Decline in the condition of remnant habitat, including threatened species habitat


  • Insufficient control
  • Difficulty of control


  • Identification of where emerging weeds are
  • Insufficient knowledge about threat level
  • Plant identification: Good versus bad
  • Not deemed an issue early in the incursion
  • Insufficient resources and competing interests
  • Difficulty getting some weeds declared
  • Reduced numbers of inspectors at point of sale (stock)

Climate impacts and adaptation needs

  • Identify areas that will be more susceptible to weed invasion under future climate change models
  • Identify ALERT weeds to prevent incursion of under climate change scenarios
  • Potential changes to weed behaviour, i.e. flowering time, spread, survival
  • An increase in fire intensity and frequency under climate projections will increase invasion risk in the swamps

Who plays a role


  • Community Groups
  • Department of Environment, Water and Natural Resources
  • Landcare Groups
  • Local Government (District Council of Yankalilla, City of Victor Harbor, Alexandrina Council)
  • Media
  • Natural Resources SA Murray-Darling Basin
  • Non-government organisations
  • Nurseries and relevant industry associations
  • Primary Industries and Regions SA - Biosecurity SA
  • SA Murray-Darling Basin Natural Resources Management Board
  • Schools (engage through NRM Education)
  • State Government

Strategies and Actions

Prevent ALERT weed incursions into the region

  • Education and capacity building for all community members regarding ALERT weeds with a potential to take hold in the region
  • Raise community awareness of high risk garden species and promote alternatives (target urban and peri-urban)
  • Support community surveillance, such as having weed identification services at Natural Resource Centres or networks such as weeds spotters
  • Monitoring of incursion pathways (i.e. major roads, laying of pipelines) and hotspots for likely incursion
  • Prevention of entry to region, keeping, movement and sale of weeds
  • Research to identify likely incursion under climate change or changed flow regimes, such as returning low flows
  • Support voluntary accreditation of nurseries and landscapers in promoting environmental considerate species

Destroy/ eradicate ALERT weed infestations where feasible

  • Detailed surveillance and mapping to locate all infestations
  • Landholders to destroy all infestations including seed banks and juveniles
  • Monitor progress towards destruction
  • Implement quarantine provisions if appropriate
  • Allocate resources to an emergency respond fund to enable early control