Many native species face significant threats such as entanglement or ingestion from debris in waterways. This can lead to behaviour changes, neurotoxicity, and death.
A program was designed to categorise the debris in the River Torrens / Karrawirra Pari, Adelaide, and its tributary catchments. The river is an iconic component of the South Australian landscape with high ecological importance and significant cultural value for Kaurna people. Overarching aims of the project are to identify potential debris sources, associated risks to wildlife, and to identify and deliver mitigative actions to reduce these risks.
Adelaide University has undertaken a trial monitoring program at the confluence of Third Creek and the River Torrens / Karrawirra Pari to evaluate the most effective and deliverable methods for the wider catchment monitoring program. Phase 2 has expanded the monitoring across the broader metropolitan area and has surveyed gross pollutant traps (GPTs), stormwater outfalls and riparian transects. Plastic material was found to be most common across all survey types comprising up to 65% of the debris collected from stormwater outfalls. On average, 36% of the material collected from the different surveys contained loops, which are considered high risk items for species such as rakali and platypus. Foam and metal items were also prevalent.
Phase 3 of the program will work towards source identification and management. The results from prior phases will then be used to develop mitigative actions. These actions may range from local behaviour change programs, to collaborating with stakeholders towards influencing policy change.