Students help restore mauri to the Oruarangi Stream
An industrial purple dye spill devastated the Oruarangi Stream ecosystem in 2013. It’s hard to believe such an event could have a positive outcome, but it was the inspiration behind a Participatory Science Platform project involving students from Aorere College, Makaurau Marae, Wai Care, NIWA and Ngā Pae o te Māramatanga.Together, they are working to restore mauri to the local awa (stream).
The project is a mix of science and local history and has become the stepping stone for further citizen science projects in the South Auckland community.
Dye affects the Oruarangi Stream
The banks and water of the Oruarangi Stream were adversely affected when over 1,000 litres of methyl violet dye leaked from an industrial storage tank. Freshwater and marine life died as a result of a dye spill.
Oruarangi Stream – an awa of local significance
Oruarangi Stream holds special significance to local iwi. Their papakāinga is Auckland’s oldest settlement. The stream was an important link to the Manukau Harbour – providing both food and navigation. The Mangere Wastewater Treatment Plant disrupted the stream’s flow for 40 years. Upgrades to the treatment plant in 1998 once again connected the stream to the harbour, and Makaurau Marae members worked to clean up and restore the stream. (Read about the history of this area in the article Ihumātao – past and present.)
In 2013, more than 1,000 litres of methyl violet dye spilled into a local catchment pit and was carried through the Oruarangi Stream. The effect on freshwater and sea life was devastating. But there is a silver lining to this tragedy.
Restoring mauri to Oruarangi Stream
In 2015, year 9 students from Aorere College teamed up with youth and elders from Makaurau Marae. They learned about the local history and stories associated with the stream. Armed with a better understanding of the link between people and place, the group worked to learn about and help restore the stream’s ecosystems. Science experts from Wai Care and NIWA guided students as they investigated water-quality testing, species diversity and ecosystems and what they can do to improve them.
Water-quality monitoring protocols
A range of standard water-quality indicators are measured on site. Physical factors include water clarity, pH, temperature and streambed type. Biological factors include micro and macroinvertebrates, plants and larger animals. Water and streambed substrate samples are often collected for off-site analysis.
Water clarity
Water clarity is an important indicator of stream health. Just like plants growing on land, aquatic plants need sunlight to grow. Aquatic plants provide food and protection for other species. Plants also produce oxygen. Stream water can become cloudy (turbid) with sediments from erosion, run-off or algae. Turbidity blocks sunlight and limits plant growth and the oxygen that plants produce. Sediments in the water also absorb heat, raising the water temperature and reducing dissolved oxygen supplies. Sediment can block the gills of aquatic animals.
Testing water clarity
Water clarity is assessed with a 1 m long acrylic tube.
pH
pH measures the acidity or alkalinity of the water. A pH of 7.0 is considered neutral. The optimal pH for many aquatic species is between 7.0 and 9.0.
Vegetation and geology can influence stream pH. Accidental spills or run-off alter pH. For example, higher than usual alkaline readings indicate an excess of lime fertiliser or detergents, both of which may cause unwanted plant growth.
Testing water for pH
pH is a water quality indicator. Chemical spills and run-off can change stream pH, making it difficult for aquatic life to thrive.
Temperature
Water temperature is mostly determined by weather, but there are land-use practices that influence temperature. Macroinvertebrates – an important part of aquatic food webs – tend to prefer cool, fast-running water. Streamside vegetation provides shade and helps to keep water cool. Removing vegetation and damming waterways, which slows or reduces water flows, can cause water to warm.
Substrate
The streambed substrate (soft or hard bottom) influences the types of organisms that live in a stream. Soft-bottomed, muddy streams often have a slower flow and more plants. Stony, gravelly, hard bottoms usually have faster flows and support a more varied invertebrate community. Changes to a stream’s substrate will affect the ecosystem it supports.
Muddy bottom
This small tributary to the Oruarangi Stream has a muddy base. This will influence the types of aquatic life that live in the stream.
Biological monitoring
Macroinvertebrates are used to assess water quality. They are easily collected in most aquatic environments. Some species, like mayflies and caddisflies, are sensitive to physical and chemical changes to their habitat. They are called indicator species because their presence or absence is an indicator of water quality. These species like cold, rushing water so they are harder to find in slow-moving streams in warmer areas, even if the water quality is considered to be good. Macroinvertebrates are affected by decreases in oxygen levels as well as by pH, temperature and substrate changes.
Macroinvertebrates are part of aquatic food webs that include larger species like eels, fish and birds.
Species count at city stream
Students involved in a citizen science project in Auckland identify and count the number of species they collected in a water sample at a local stream. A diverse species count can be an indication of good water quality.
Any work to restore a stream must begin with a stock-take of what species are present and what issues are likely affecting the stream.
Community outcomes
The project established more than just baseline data from which to judge water quality in the Oruarangi Stream. The students learned scientific protocols in a relevant and meaningful context. Strong personal links developed between students, the marae community and science professionals. The timeline River investigations and the nature of science documents many of these moments.
River investigations and the nature of science
Students from Manurewa High School and rangatahi from Makaurau Marae investigated the ecological restoration of the Oruarangi Stream. Learn about their work and how it reflects the nature of science.
Note: To use this interactive timeline, move your cursor or finger over any of the labelled boxes and select to get further information. You can also scroll forwards and backwards or use the arrows in the top section.
Transcript
1 July 2013 – Dye spill
More than 1,000 litres of dye spills into the local Oruarangi Stream system.
Nature of science
Science is a knowledge system. Scientific research is not about emotional or legal responses, such as assigning blame – it works to identify and assess any damage and facilitate restoration.
Acknowledgement: Eel image © Auckland Council and Stream image © Te Warena Taua
1 August 2013 – Ongoing restoration
Iwi and Auckland Council continue with restoration work that had been in progress prior to the dye spill.
Nature of science
Participatory science is a form of science in which the community is actively involved in all aspects of a project, often working alongside scientists.
Acknowledgement: Victoria Metcalf/Participatory Science Platform
1 February 2015 – Asking questions
Students from Aorere College and rangatahi from Makaurau Marae ask how they could measure the effectiveness of the stream restoration projects.
Nature of science
Observing and asking questions is a fundamental scientific process. Questions form the base of every scientific investigation.
Acknowledgement: Sarah Morgan/Comet Auckland
June 2015 – PSP funding
Aorere College teacher Chloe Innes applies for funding. The government’s Participatory Science Project pilot projects are selected.
Nature of science
Science both influences society and is influenced by society. As society’s priorities change, so do scientific priorities. Funding is often tailored to meet these priorities.
Acknowledgement: Crown copyright, 2016.
16 November 2015 – Mātauranga Māori
Students spend the night at Makaurau Marae. They learn about the validity of cultural knowledge passed down through generations.
Nature of science
Mātauranga Māori recognises that Māori have a long and close association with the natural environment, collected by careful observations, often over years or even generations. This information is important for how we understand changes over time.
Acknowledgement: Sarah Morgan/Comet Auckland
17 November 2015 – Collaboration
Students work with scientists from NIWA and Waicare. The experts introduce students to sampling and identification protocols.
Nature of science
Collaboration is common among scientists. Each person can bring specialist knowledge to a project. Combining different areas of expertise adds depth to investigations.
Acknowledgement: Sarah Morgan/Comet Auckland
24 November 2015 – Fieldwork
Students use the protocols to gather data on water quality.
Nature of science
Data is recorded observations. Data needs to be collected systematically. Collected data also needs to be relevant to the questions that have been asked. Using standard scientific protocols helps ensure reliability of results, enabling data points to be compared.
Acknowledgement: Sarah Morgan/Comet Auckland
24 November 2015 – Ethical decisions
Students leave nets out overnight to sample fish species. They catch both pest and native species. Students decide not to return pest fish to the stream.
Nature of science
Credible scientific evidence can help address difficult socio-scientific issues like pest control.
Acknowledgement: University of Waikato. All Rights Reserved.
24 November 2016 – Microscopy and biological drawing
Students return to Aorere College and use magnifying lenses and microscopes to identify macroinvertebrates collected during fieldwork. They make observational drawings.
Nature of science
Scientific observations can be made directly with our own senses – sight, for example – or we can extend and refine our basic senses with tools like microscopes.
Acknowledgement: Sarah Morgan/Comet Auckland
26 November 2016 – Sampling setback
Students are unable to complete fieldwork due to E. coli contaminating the stream water.
Nature of science
It is common for scientific investigations to suffer setbacks, for example, when something unexpected and dangerous occurs or because of changes to funding, staff or even public perceptions.
Acknowledgement: Public domain
2 December 2015 – Documenting the research
Student groups choose a variety of methods to present their findings – via slideshows, videos and skits.
Nature of science
Scientists share their findings in many ways – from informal conversations with peers through to the all-important publication in journals, where the work is first reviewed by other scientists.
Acknowledgement: Sarah Morgan/Comet Auckland
7 December 2015 – Presenting the research
Students present their findings to whānau and manuhiri and finish the project with kai.
Nature of science
Scientific investigations often bring people from a range of experiences together for a shared purpose.
Acknowledgement: Sarah Morgan/Comet Auckland
1 July 2016 – Asking new questions
Aorere College applies for and receives new PSP funding to answer new questions about local waterways.
Nature of science
Scientific research isn’t something that is ever considered ‘finished’. Scientists regularly use information from past research to help shape new investigations.
Acknowledgement: Sarah Morgan/Comet Auckland
Makaurau Marae hopes to continue with the project, bringing in new students each year to collect and compare data, monitor changes to water quality and species diversity and continue with the restoration of mauri to their awa.
Mauri is an integral part of being Māori. Dr Kepa Morgan established a 'mauri model' in order to aid environmental workers and iwi in their work to determine environmental impacts and solutions in situations like water contamination.
Nature of science
Science is more than the collection and interpretation of data. Science has a social side – as demonstrated by the strong personal links created and fostered by this project. Scientific investigations bring people from a range of experiences together for a shared purpose.
Related content
Restoring Te Auaunga – Oakley Creek looks at the history of this Auckland awa and how its restoration benefits both ecosystems and communities.
Activity idea
Te mana o te wai explores the concept of mauri – the health and wellbeing of a waterway.
Useful links
NIWA has an online Stream Health Monitoring and Assessment Kit that enables non-scientists to collect consistent, scientifically valid information from small rural streams.
Manaaki Whenua – Landcare Research has an online Freshwater invertebrates guide to assist community groups with monitoring freshwater invertebrates in New Zealand.
Funding
Students from Aorere College and Makaurau Marae have teamed up to restore the mauri of the Oruarangi Stream. The project has received funding from the South Auckland pilot of the Participatory Science Platform (PSP) – a programme that is part of the Curious Minds initiative and funded by the Ministry of Business, Innovation and Employment. The PSP is currently being implemented as a pilot in three areas: South Auckland, Taranaki and Otago.
The South Auckland pilot of the PSP is managed by COMET Auckland (Community Education Trust Auckland). COMET is a council controlled organisation of Auckland Council and an independent charitable trust. Its role is to advance education in Auckland by supporting education and skills across the region. COMET Auckland hosts the Auckland STEM Alliance which is leading the pilot in South Auckland. The Auckland STEM Alliance brings together businesses, educators and government.
The Government’s national strategic plan for Science in Society, A Nation of Curious Minds – He Whenua Hihiri i te Mahara, is a Government initiative jointly led by the Ministry of Business, Innovation and Employment, Ministry of Education and the Office of the Prime Minister’s Chief Science Advisor.
