Merri Creek Management Committee

ZarasGroupCleanUpMay2021MCMC supports many litter clean-ups undertaken by community volunteers. We give our thanks to Zara Hakam who organised a litter clean-up in East Brunswick for a university assignment and wrote about her experience, explaining how it relates to broader ecological issues. 

Of the 13kg of litter Zara and her six friends collected in one hour along Merri Creek in May 2021, over 97% was plastic. Most were single use items such as disposable face masks (9), plastic bottles (18) and plastic straws (35). Zara calculated that if these levels of litter were found along the entire 60-kilometre length of the creek, the Merri would hold approximately 2.5 million individual pieces of plastic!

MCMC supported Zara's clean-up efforts with advice and equipment.

Photo: Zara, 2nd from left, and friends sorting Merri Creek litter

To read Zara's report, follow the read more prompt.

MERRI CREEK LITTER - by Zara Hakam

Introduction

By hosting a litter pick-up event along Merri Creek, I sought to contribute to my community’s long-standing efforts to protect the ecology of Merri Creek and reduce the amount of rubbish entering Port Phillip Bay. I also aimed to gain a better understanding of how anthropogenic waste impacts the environment.

Methodology

On Saturday 1 May 2021, six of my friends and I collected rubbish along Merri Creek within 50 metres south of the footbridge near Sumner Reserve and Northcote High School. Litter was collected between 12:00 and 1:00 pm and was removed using pick up sticks and placed into large, reusable hessian sacks.

Based on the MCMC’s recommendations, the bags of litter were weighed and separated into five broad categories (metal, plastics, glass, polystyrene, other). Each piece of litter was counted as a single item regardless of size, and some approximations were made. All rubbish was put into appropriate bins, and the data was uploaded on-line to LitterWatch Victoria.

Results

In one hour, a total of 13 kg of litter was collected. Most of the litter was caught in tree branches and plants along the creek’s bank. A summary of the prevalence of different types of litter is provided in the following table.  

Type

Sub-category

Item Count

Total

Percentage of Total Items

Plastics

Medical/sanitary

15

2058

97.5%

Food/packaging

278

Other/unidentifiable

1754

Cigarette related

3

EPS

8

Glass

Bottles

2

2

0.1%

Metal

Aluminium

10

14

0.7%

Other metals

4

Other

E-waste

2

37

  

1.8%

Rubber

1

Textiles

33

Miscellaneous

1

 

2111

Zaralittercleanup2021Table 1: This table is a simplified version of the results I uploaded to LitterWatch Victoria (https://www.litterwatchvictoria.org.au/) – for more detail, see appendix.

Discussion

Within the area of Merri Creek surveyed, over 97% of the litter collected was plastic. Of this figure, most were single use items, such as disposable face masks (nine), plastic bottles (18), and plastic straws (35). If these levels of pollution remain consistent for the entire 60-kilometre length of the creek, the Merri would hold approximately 2.5 million individual pieces of plastic.

As the Yarra River’s second-largest influent, it is evident that plastic pollution in Merri Creek has major ecological consequences for Port Phillip Bay (Preston, 1989, p.123). Rivers such as the Yarra are major disseminators of land-based refuse, and consequently, plastic comprises over 80% of total oceanic rubbish (Almroth et al., 2019, p.317). The risk plastic poses to marine animals through suffocation, injury and entanglement is well-documented. Additionally, research by Everaert et al. (2020) posits that the blankets of plastic debris floating on top of the Mediterranean and Yellow Sea blocks sunlight from penetrating the surface and is likely to have “harmful effects” on marine ecosystems (p.8).

The ecological consequences caused by plastics also relates to the way they break apart over time to form microplastics (smaller than 5mm). Due to their small size and low density, these fragments disperse easily by water and wind and are present all over the globe. They are entrenched in the geological layers of the earth and have even been found on the moon (Zalasiewicz, 2019, p.63). As plastic fragments to form microplastics, there is evidence that these particles have the potential to both adsorb and release toxic substances. Consequently, once exposed to these particles, some aquatic invertebrates have been found to exhibit hormonal and reproductive changes (Zalasiewicz, 2019, p.148-150). Similarly, in another recent study, it was found that plastic residue in soil may impede nutrient absorption in plants (Chen et al. 2021, p.9). While risks such as these have been acknowledged by the scientific community, evidence about microplastics is still considered to be in its preliminary stages.

Conclusion

After investigating both the type and prevalence of rubbish in Merri Creek, I discovered that plastics are ubiquitous not only in my local aquatic environment but are the most abundant form of litter in the ocean. By drawing on recent research, I have illustrated how plastic pollution has long-term, wide-reaching environmental risks – many of which are yet to be discovered.

Photo: The author in action on the litter clean-up day.

Bibliography

Almroth, B.C., & Eggert, H. (2019). Marine Plastic Pollution: Sources, Impacts, and Policy Issues. Review of Environmental Economics and Policy, 13(2), p.317–326. https://doi.org/10.1093/reep/rez012
Chen, Y., Awasthi, A. K., Wei, F., Tan, Q., & Li, J. (2021). Single-use plastics: Production, usage, disposal, and adverse impacts. The Science of the Total Environment, 752. https://doi.org/10.1016/j.scitotenv.2020.141772
Everaert, G., De Rijcke, M., Lonneville, B., Janssen, C. R., Backhaus, T., Mees, J., Van Sebille, E., Koelmans, A. A., Catarino, A. I., & Vandegehuchte, M. B. (2020). Risks of floating microplastic in the global ocean. Environmental Pollution, 267, p.1-9, https://doi.org/10.1016/j.envpol.2020.115499
Preston, G. (1989, February). Merri Creek Management Plan [Paper Presentationhttps://search-informit-org.ezproxy.lib.rmit.edu.au/doi/10.3316/informit.519352103303695">https://search-informit-org.ezproxy.lib.rmit.edu.au/doi/10.3316/informit.519352103303695
Zalasiewicz, J. A. (2019). The Anthropocene as a geological time unit: a guide to the scientific evidence and current debate. Cambridge University Press.

Note - during COVID 19 restrictions

MCMC offers litter clean-up gear via our "click and collect" service and Julia Cirillo is available for advice on safe litter sites, etc: This email address is being protected from spambots. You need JavaScript enabled to view it..
For further information on litter cleanups, go to: https://www.mcmc.org.au/get-involved/volunteering-opportunities.

Merri Events Calendar