Impacts of plastic pollution on Australia’s marine environments

Globally, plastic litter in the marine environment is a major environmental concern. Reaching all the oceans of the world in substantial quantities, plastic litter is negatively affecting marine life, ecosystems, communities, and even human health (through bioaccumulation up the food chain). 

The marine plastic pollution challenge 

According to research by the CSIRO: 

• Around the world, nearly half of all seabird species are likely to ingest debris. 

• Approximately one third of marine turtles have ingested debris, with most items eaten by turtles being plastic and buoyant. 

• Within Australia, approximately 75% of the rubbish along the coast is plastic and is from Australian sources, with debris concentrated near urban centres.  

• In Australian coastal and offshore waters, most floating debris is plastic.  

• Human deposition is the most important factor in determining how much plastic debris can be found at a site.  

https://www.csiro.au/en/research/natural-environment/oceans/marine-debris 

What can be done about marine plastic pollution? 

Plastic litter is difficult and costly to clean up once it has entered marine environments. The most effective mitigation strategy for plastic litter is prevention.  

This can be achieved either through litter reduction strategies or through reducing the consumption of plastic items that have the greatest potential to be littered (e.g., single-use plastic or SUP items). Recent Marsden Jacob studies found that SUPs are 13 times more likely to be littered as compared to other plastic items. 

Working together, industry, governments and communities can make significant strides to reduce marine debris impacts in coastal areas and in the marine environment 

Projects that tackle the plastic pollution problem 

Over the past few years, Marsden Jacob has undertaken circular economy projects for a wide range of government agencies at both state and Commonwealth levels. These projects have focused on reducing litter impacts and improving recycling and recovery outcomes through initiatives such as: 

• The phase out or banning of single-use plastic (SUP) items (e.g., lightweight plastic shopping bags, plastic straws).  

• Incentives to reduce plastic debris, such as the introduction of new container deposit schemes (CDS) into more Australian states and territories. 

• Expansion of the scope of containers eligible for established container deposit schemes and plastics that are eligible for kerbside recycling. 

Measuring plastic litter in marine environments 

In undertaking these studies, Marsden Jacob typically use three key data sources to estimate litter counts and volumes for terrestrial and marine settings:  

1. The Australian Litter Measure (ALM) – collected across a range of sites in metropolitan and regional areas, and both inland and coastal areas, covering beaches, industrial, recreational parks, residential, and retail.

2. Key Litter Items Study (KLIS) data – surveys all the litter items at low tide found between the waterline and the high tide mark along transects that follow the shoreline. 

3. The (recently superseded) National Litter Index (NLI) data. 

We use statistical techniques to combine these data sets and estimate litter propensities. The baseline litter propensity for each item type is a key input to any economic analysis (e.g., cost-benefit analysis) because it is against this baseline level that the effectiveness of a policy initiative is measured. For example, the inclusion of a type of beverage container within the CDS might reduce its litter propensity from 5% to 2-3% due to the financial incentive to redeem the container rather than litter it. 

Although plastic litter is a serious marine pollution problem, Marsden Jacob is hopeful that our waste reduction modelling and litter data analysis can help #ShapeTheFutureWisely. We look forward to continuing to collaborate with the public and private sectors to develop and improve recycling and recovery initiatives and circular economy outcomes across Australia’s marine and coastal environments.   

For more information, contact Marsden Jacob’s circular economy specialists, David Rogers: https://www.marsdenjacob.com.au/profile/dr-david-rogers/ and Peter Kinrade: https://www.marsdenjacob.com.au/profile/dr-peter-kinrade/.