Tiny Plastics, Big Problems

Microplastics – tiny plastic particles that are smaller than 5 mm – have been found in our food, water, and even in the most remote places on Earth like Antarctica and Mt Everest. But they are even closer than that: recent research has found that microplastics are in our bodies, as we ingest up to 52,000 microplastic particles a year (and that’s not even counting the particles we inhale)!

Mirco Investigator scientist Zac from Waverley Park School collecting samples at the Otepuni Stream, Invercargill
Zac from Waverley Park School collects microplastics using a
plankton net at Otepuni Stream
Pūtaiao Tamariki (Science Kids) programme
This is bad news because microplastics can affect our health and environment through a variety of effects, namely carrying toxic contaminants on their surface and accumulating up the food chain, where they could up end on our dinner plates. The combination of these two effects could be even worse over the years, as the cumulative effect of ingesting microplastics with toxic properties or carrying toxins could wreak havoc on our immune systems. What’s worse is that plastics are just everywhere. Our single-use plastic lifestyle means that plastic litter is pervasive and often ends up in all sorts of natural environments where they eventually break down into tiny microplastics.

The majority of literature on plastic pollution is focused on the marine environment, but only a handful of studies in New Zealand have quantified microplastics present in waterways despite evidence suggesting that rivers contain the highest concentrations of plastic pollution. A further complication is the many varied techniques of sample collection, quantification, and identification, preventing scientists from comparing findings. This is where the Micro-Investigators project comes in: a citizen science programme investigating concentrations of microplastics in Invercargill waterways.

Project overview and whāinga

Using established techniques from existing literature, our project adapts and employs a straightforward, inexpensive, and accessible standard operating procedure to sample microplastics in waterways in Invercargill. The procedure involves quick and easy sampling methods, as well as equipment and chemicals that are generally available in a school chemistry laboratory.

The whāinga (goal) is to present a simple and standardised approach that can be easily applied by other students and classrooms, empowering communities through environmental education and addressing the paucity of nationwide data on waterway microplastics through citizen science. By first quantifying the state of microplastic concentrations in New Zealand waterways, measurable efforts can be implemented to reduce microplastic pollution and inform mitigation strategies. In addition, our goal is to raise awareness and to educate the public about the harm of microplastics in our environment because it’s hard to care about what you can’t see, and it’s hard to protect what you don’t care about.

"…it’s hard to care about what you can’t see, and it’s hard to protect what you don’t care about."

Project history and the mahi so far

In 2019, Niamh Edgington – a research student in SIT’s Environmental Management degree programme – began an investigation of microplastics concentrations in two Invercargill inner-city waterways.  At the time, there were no published findings on microplastics in NZ waterways and it was clear that there was a paucity of knowledge around the existence and extent of microplastics pollution in the country.  Since then, a study quantifying microplastics in Auckland region waterways was released, as well as a study from Otago University.  There has also been a handful of information on government initiatives, including an Environment Southland commissioned report by the Cawthron Institute on the risks of microplastics in Southland.  This shows that New Zealand is at the forefront of microplastics research with academic projects and government initiatives (e.g. Scion, ESR, MPI, NIWA, MBIE) coordinating efforts towards quantifying and characterising microplastics pollution.

This is an opportunity for New Zealand to be a leading example in the widespread effort to quantify, monitor, and subsequently mitigate the spread of microplastics in the environment. We believe that the best approach towards an immense effort like this is to engage and enlist the community through citizen science: by developing a simple quantification method for use by citizen scientists, ‘hotspots’ that warrant more focus and extensive characterisation can be identified.  This can help us to better understand the sources and inform mitigation strategies.

Niamh found microplastics in both her study sites – the Waihopai River and the Otepuni Stream – and 11 out of 16 samples showed a presence of microplastics.  The number of microplastics in her samples ranged from 0 to 25 particles.  She also found that over the course of the sample period, Otepuni Stream had consistently higher numbers of microplastic particles compared to the Waihopai River.

In 2020, another research student in the Bachelor of Environmental Management – Cicy Zhang – took the project one step further and measured river flow during sample collection so that she could work out the concentration of microplastics in the river.  In addition, a USB microscope was used in the visual examination step so that she could see the tiny particles better (Niamh previously had only counted larger microplastics measuring 1-5 mm).  Using this microscope, Cicy was able to categorise the microplastics she found into type and colour, in order to provide clues to the origin and source of the fragments.  Cicy found that the two rivers were polluted by microplastics in varying degrees (0 to 231 particles per sample, or 0 to 3.87 particles per m3).  These microplastics were categorised into four main shapes: foam, film, fibre, and fragment, and into seven different colours.  The most common shape by far was hard plastic fragments (up to 219 pieces per sample) and the prevailing colours were white and transparent pieces.

Micro-Investigators and Pūtaiao Tamariki (Science Kids)

Over the past two years, we have had great success measuring microplastics with secondary and tertiary students at SIT, continuing the mahi of monitoring microplastics concentrations in Invercargill waterways as class exercises and student research. 

The next step in the citizen science programme was to establish partnerships between Invercargill schools and community groups in order to share our knowledge and resources with the public.  This month, we had the amazing experience of working with the Southland Community Nursery and Pūtaiao Tamariki (Methodist Mission Southern), a programme that offers environmental field sessions to schools, giving students from all backgrounds the chance to explore science in a manner that is fun, interactive, environmental, and cultural.

As part of the programme’s “Awa” session, we were able to trial the Micro-Investigators project with kids from Waverley Park School, Ascot Community School, and Donovan Primary School. They were all ecstatic to hear that they would be doing science, which made them all citizen scientists! In addition to collecting microplastics samples, they learned about and tried different methods of measuring water quality, as well as how awa fit in te ao Māori and their importance to tangata whenua.  

We carried on our ethos of collaboration between all levels of education by enlisting high school students from Southland Girls’ High School to help with the chemistry lab work component of the methodology: the school kids had collected the microplastics for us, and now the high school students would isolate and extract the microplastics in the lab. It was delightful to see that kids from every age group from the wee ones to the teens were engaged and showed a great interest in the science.

In collaboration with WasteNet Southland, we are in the process of setting up a website hub for schools and citizen scientists to upload and view their microplastics data. With this long-term repository of data, it will be possible to compare over time and monitor the state of microplastics in our waterway. An added bonus is that the kids find it so cool that they have published data as citizen scientists!

Te ara and future outlook

We are hoping to secure funding from sources such as Unlocking Curious Minds (MBIE) or the Waste Minimisation Fund (Ministry for the Environment).  This funding will enable us to run our citizen science programme with schools, community groups, and tertiary institutions beyond the region. The merger of polytechnics and institutes of technology into Te Pūkenga (formally known as NZIST) is not only an opportunity for collaboration of expertise on this project, but also to explore expanding Micro-Investigators nationally through the different hubs.

This partnership approach enables the possibility of sharing resources between schools and better-equipped institutions for laboratory aspects of the project, and also facilitates the dialogue around microplastics pollution while fostering a heightened sense of community. An added benefit of the programme is that the partnership between schools and Te Pūkenga institutes will help in the recruitment of future students, as well as promoting interest in STEM related courses.

Children and students from all levels of education and all walks of life will be able to take part in this important mahi – they will be able to learn about microplastics in our waterways and can teach their whānau in turn. Only when microplastics are no longer “invisible” to us will people begin caring and take action towards reducing microplastic pollution in our environment.


Micro-Investigators Photo Gallery

For more information contact Christine Liang, Programme Manager of Environmental Management at Southern Institute of Technology.