A study is underway to measure the amount of plastic pollution in the Swan Canning estuary and to determine the impact of WA’s Plan for Plastics as it takes effect over the next five years.
The study will provide baseline data before the introduction of WA’s Plan for Plastics, which will see the phasing-out of a range of single-use plastics including plates, cutlery, stirrers, straws, thick plastic bags, polystyrene food containers and helium balloon releases.
The Swan Canning Estuary supports biodiverse floral and faunal communities. However, as an urban estuary, elevated nutrients, increasing salinity and temperature and other contaminants can impact on the biodiversity. While data is collected on these factors, plastic pollution has not yet been studied across the entire system. Understanding the prevalence, sources, and potential for impact of plastics is vital for the effective management of the Swan Canning Estuary.
The study will be undertaken by the Department of Biodiversity, Conservation and Attractions and the Department of Water and Environmental Regulation. The first phase, to be conducted this week, is to test the methodology for sampling the shore and riparian zones (land directly adjacent to the river from the water mark up into the fringing aquatic vegetation) on the Applecross, Bicton and Point Walter shorelines.
Data gathered over an 18-month period will provide information about plastic pollution across multiple locations on the estuary and at different times of the year. The project aims to determine the distribution, extent and types of plastics found in surface water and on the banks, make seasonal comparisons, and establish if the sources of plastic pollution can be determined.
DBCA Rivers and Estuaries Science Environmental Officer Dr Peter Novak said the information collected would provide a snapshot of plastic pollution in the estuary before the introduction of WA’s Plan for Plastics.
“Most human-caused marine debris is made up of plastics, which pose a health risk to marine animals. When these plastics are ingested by animals, they may lodge in the gut causing a decline in health and potential starvation. Pollutants from the plastic may accumulate within the animal’s tissue and enter the food chain,” Dr Novak said.
“This research will give us a baseline of plastic pollution and will be used to assess the extent of the problem in the Swan Canning Estuary, its potential impact to the river’s ecosystem and importantly the success of future environmental policy actions.”
DWER Senior Environmental Officer Joanne O’Connor said similar comparisons of beach clean-ups before and after the State Government’s 2018 plastic bag ban showed fewer plastic bags were contributing to beach litter after the ban was introduced.
“We can safely assume that a ban on a range of single-use plastics will result in fewer microplastics entering the environment, but this study will help determine the impact on our river systems and their surrounds, as well as hopefully determine the sources of plastics pollution,” Ms O’Connor said.
