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  • Backyard Battle is a citizen science programme run by Keep New Zealand Beautiful. It gets students, teachers, volunteers and other citizen scientists out collecting litter at key inland sites such as public recreational spaces, highways and railways, car parks and residential, retail and industrial sites. The goal is to help create a better understanding of litter’s pathway across the land of Aotearoa New Zealand.

    Rights: Keep New Zealand Beautiful

    Backyard Battle

    Keep New Zealand Beautiful’s Backyard Battle sees students become citizen scientists as they act to prevent litter entering our waterways whilst also collecting valuable data.


    Reach: New Zealand

    Nature of science focus: As a citizen science programme, this project allows students to experience a range of aspects of the Nature of Science (NoS). Backyard Battle links students to real-life science, giving them the opportunity to participate in science processes and contribute to national and international research.

    Identify aspects of NoS that your students need to develop their understanding of and frame your unit to focus these aspects within the context of Backyard Battle.

    Science capability focus: As a hands-on interactive and experiential learning opportunity, Backyard Battle aligns with the curriculum focus on the development of capabilities that are strengthened through practice. This project has the scope to develop all the science capabilities – Participating and contributing, Investigating science, Understanding about science, Engage with science, Gather and interpret data, Use evidence, Critique evidence, Interpret representations.

    Identify which ones your students need to develop or understand more fully and then frame your pedagogy to be very clear about these things when you do them.

    Rights: Keep New Zealand Beautiful

    Sorting litter

    Once litter is collected during a Backyard Battle, it is sorted into categories enabling the collation of data that will help Keep New Zealand Beautiful create a better understanding of litter’s pathway across Aotearoa.

    Science focus: Living World – ecology; Planet Earth and Beyond – interacting systems, pollution, environmental science, waste, sustainability

    Some suggested science concepts:

    • Litter and waste impact natural ecological systems.
    • Ecosystems maintain interacting systems such as the water and carbon cycles. The impact of litter and different forms of waste becoming part of these cycles impacts the environment and the climate.
    • Socio-ecological issues such as waste stem from manufactured products used mostly on land.
    • Chemicals used in the manufacturing process and within materials that become waste impact ecosystems.
    • The difference between natural and human induced impacts of waste.

    Some examples of learning outcomes:

    Students can:

    • ask questions, find evidence, explore simple models and carry out appropriate investigations to develop simple explanations
    • explore and act on issues and questions that link their science learning to their daily living
    • explain how living things are suited to their particular habitat and how they respond to environmental changes, both natural and human induced
    • find out about the uses of common materials and relate these to their observed properties
    • investigate the water cycle and its role in climate, landforms and life
    • describe how natural features are changed and resources affected by natural events and human actions.

    Backyard Battle has been readily adopted by schools nationwide that embrace environmental education and who seek to engage their students as citizen scientists.

    Keep New Zealand Beautiful CEO Heather Saunderson

    About Backyard Battle

    Litter starts out as something that we’ve created and used. If inappropriately disposed of, these products become litter that pollutes land, waterways and oceans. It causes harm to the environment we live in, the water we drink and the ecosystems we’re a part of. It’s not just our activities out at sea or on our rivers and lakes that cause water pollution – a vast majority of litter found in our oceans and waterways comes from land-based activities by being washed or blown into the water by rivers, waterways, sewage, stormwater or winds. This means that the litter we see inland poses an extreme risk to life both on land and in the water!

    Rights: Keep New Zealand Beautiful

    Auditing litter

    Backyard Battle not only sees students taking meaningful action towards keeping New Zealand Beautiful, it also has them engaged in real-world data collection.

    In 2019, Keep New Zealand Beautiful carried out a National Litter Audit that compiled empirical data through comprehensive physical inspection and visual counting of litter in a number of specific fixed sites. The methodology and monitoring plan for the National Litter Audit was developed in consultation with Stats NZ, the Department of Conservation and the Ministry for the Environment to ensure that the audit provided high-quality, robust statistics and baseline data on litter across Aotearoa. Because of the success of the 2019 audit, with the findings used to inform policy development at both a local and national level, Keep New Zealand Beautiful embarked on a second National Litter Audit in 2022. All citizen scientists can join in auditing New Zealand’s litter problem by completing one (or more!) Backyard Battles – the citizen science version of the National Litter Audit. With your contribution, more ground, more seasons and more time points can be covered.

    Rights: Keep New Zealand Beautiful

    Contributing to a national dataset

    As Backyard Battle citizen scientists, students involved collect, sort and weigh litter. They contribute to a dataset that helps Keep New Zealand Beautiful understand how litter makes its way from the land to the ocean through our waterways.

    Backyard Battle is a citizen science programme run here in Aotearoa by Keep New Zealand Beautiful. It uses a similar methodology as the National Litter Audit but each survey will be conducted by citizen scientists from all over New Zealand.

    The data collected from Backyard Battle will provide a secondary dataset to the National Litter Audit and will contribute to growing our national knowledge base about the type, location and density of litter in Aotearoa and how it makes its way from the land to the ocean through our waterways.

    The data will also be available for research and to help inform local and national legislation as well as helping Keep New Zealand Beautiful target its programming and behaviour change campaigns into the areas of our communities most in need.

    Nature of science

    As a citizen science programme, Backyard Battle aims to enable students to become “responsible citizens in a society in which science plays a significant role” ( by linking students to real-life science, giving them the opportunity to investigate and contribute to national and international research.

    Related content

    This resource explores the different ways we deal with rubbish.

    In this activity, students play an active game to sort plastic items into three categories: reuse, recycle and rubbish. The image We can sort rubbish according to its properties has useful links to explore alongside this activity.

    The future of plastics: reusing the bad and encouraging the good dives further into this socio-ecological issue.

    Planning pathways – thinking about plastic provides ideas and resources for teaching and learning about plastics.

    This Connected article looks at a project called sea science.

    Read the Connected article Down the drain to see how students in Petone, Lower Hutt, took action to prevent rubbish from entering their local marine environment.

    We have curated information from the Building Science Concepts Book 60 Rubbish: How Do We Deal with It? for use in the early to middle primary years.

    Human litter has worked its way into remote and inaccessible parts of the ocean where even humans haven’t managed to penetrate. The article Oceans of rubbish explores a large-scale survey of the Earth’s oceans.

    Citizen science

    Here are some planning tips for when you intend to use a citizen science project with your students. See these helpful webinars: Getting started with citizen science and Online citizen science.

    See Mizuiku Upstream Battle, also run by Keep New Zealand Beautiful, which aims to collect and audit litter at key upstream sites such as rivers, lakes and streams to help provide a better understanding of the root causes of ocean pollution.

    Check out how one teacher used The Plastic Tide citizen science project in this unit plan and case study. There are lots of other associated resources in these articles.

    Try these similar citizen science projects with your class: Litter Intelligence and Litterati.

    Useful link

    Find out more about the 2022 National Litter Audit on the Keep New Zealand Beautiful website here, including the option to download the full report.


    This citizen science article has been written by Rebecca Hampton from Keep New Zealand Beautiful.

    Rights: Keep New Zealand Beautiful

    Keep New Zealand Beautiful

    Keep New Zealand Beautiful is a not-for-profit organisation that has been inspiring tidy Kiwis to ‘Do the Right Thing’ and Keep New Zealand Beautiful since 1967.

      Published 1 August 2023 Referencing Hub articles
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