User Guide
for the
Mauri Compass Stream Health Assessment App
A holistic approach to understanding freshwater health through integrated scientific and cultural perspectives
Build: v2.12.1 (20260115-1731)
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An Integrated Approach to Stream Health
The Mauri Compass Stream Health Assessment APP uses a series of interconnected modules to assess the ecological, physical, chemical, and cultural health of a stream.
Each module focuses on a specific aspect of the freshwater environment, such as water quality, habitat condition, biological communities, and cultural values.
Together, these modules provide a holistic understanding of stream health, allowing both scientific indicators and mātauranga Māori perspectives to be considered.
This integrated approach supports informed kaitiakitanga by showing not only the current condition of the stream, but also how human activities and natural processes influence the mauri of the waterway over time.
Macroinvertebrates (MCI)
How the data is recorded
Using the Macroinvertebrates (MCI), aquatic invertebrates found at the site are identified and recorded. Invertebrates are collected from the stream bed using a kick net or by hand from rocks and submerged vegetation. Each species observed is selected within the app by clicking on its image and recording its presence and abundance. The app automatically calculates an MCI and QMCI score based on the sensitivity of the species present.
Why this is measured
Macroinvertebrates are excellent bioindicators because different species have varying tolerances to pollution, sediment, and low oxygen levels. Since many species live in the stream for months or years, they reflect long-term water quality, not just conditions on the day of sampling.
What it shows
- High MCI scores indicate clean, well-oxygenated streams
- Low MCI scores suggest pollution, habitat degradation, or sedimentation
- Results contribute strongly to understanding ecological health and mauri
Key Indicator: Macroinvertebrates reflect long-term water quality conditions, making them essential for understanding stream health over time.
Water Quality Module
How data is recorded
In the Water Quality module, measured values are entered directly into the app for a range of physical, chemical, and microbiological parameters. These include pH, temperature, conductivity, water clarity (two clarity measurements), nitrate, phosphate, and E. coli. Measurements are taken in the field using appropriate equipment such as water quality probes, clarity tubes, and water sampling bottles.
The app also requires site information including site name, assessor name, date, GPS coordinates, and a site photo.
In addition to numerical measurements, a Site Health Check section allows the assessor to record qualitative observations such as unusual smells, visible pollution, obstructions, sediment, bank condition, flow rate, and surface features (e.g. foam or oily films).
Why this data is collected
Water quality directly controls whether a stream can support aquatic life, be used safely for recreation, and sustain mahinga kai. Chemical and bacterial indicators can reveal pollution from land use, wastewater, or agricultural runoff, while visual observations help identify immediate or obvious stressors that may not yet be reflected in biological data.
What it shows
- Whether water chemistry is within suitable ranges for freshwater organisms
- Evidence of nutrient enrichment, faecal contamination, or pollution
- Short-term stressors affecting stream health and mauri
Periphyton Module
How data is recorded
The Periphyton module involves visually estimating the percentage of the streambed covered by algae or slime. Coverage is selected using predefined ranges (0–20%, 20–40%, 40–60%, 60–80%, or 80–100%). Additional characteristics are recorded by selecting the periphyton type (green, brown, black, or mixed), thickness (thin, moderate, thick), and texture (slimy, filamentous, crusty). Site information, GPS coordinates, date, and a stream photo are also entered.
Why this data is collected
Periphyton responds rapidly to changes in nutrient levels, light availability, and flow. Excessive algal growth often indicates nutrient enrichment and reduced flushing flows, while very low periphyton may indicate frequent disturbance or shading.
What it shows
- Early warning signs of nutrient pollution or eutrophication
- Balance (or imbalance) between nutrients, light, and flow
- Impacts on habitat quality and oxygen levels
Macrophytes Module
How data is recorded
In the Macrophytes module, all aquatic plant species observed at the site are selected from the list provided in the app. Species are identified as native or introduced, and their growth form (emergent, submerged, floating) is shown. The assessor also estimates total plant coverage using percentage ranges and selects the dominant plant type present. Standard site information and a stream photo are recorded.
Why this data is collected
Aquatic plants influence flow, sediment accumulation, and habitat complexity. Native plants often support healthy ecosystems, while invasive or excessive macrophyte growth can reduce oxygen levels, alter flow patterns, and displace native species.
What it shows
- Degree of natural versus modified plant communities
- Presence of invasive species indicating ecological stress
- Long-term habitat condition and stability
Fish Module
How data is recorded
The Fish module records all fish species observed at the site. Species are selected from the app's list, which includes native and introduced fish. Observations are based on visual surveys, netting, or trapping where appropriate. Site information, GPS coordinates, date, and a stream photo are also entered.
Why this data is collected
Fish are culturally significant and sensitive indicators of stream health. Their presence depends on habitat quality, water quality, stream connectivity, and the absence of barriers such as culverts or dams.
What it shows
- Suitability of habitat for native freshwater fish
- Stream connectivity and migration pathways
- Cultural health and mahinga kai potential
Fish are culturally significant and sensitive indicators of stream health, reflecting habitat quality, water quality, and stream connectivity.
Stream Habitat Module
How data is recorded
The Stream Habitat module uses visual assessment to score physical features of the stream. The assessor selects options describing bank condition (stable, eroding, slumping, artificial), riparian vegetation coverage, shading, channel modification, and pool–riffle sequence. Additional observations can be recorded in a free-text field. Site information, GPS coordinates, date, and habitat photos are also included.
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Why this data is collected
Physical habitat forms the foundation of stream ecosystems. Even where water quality is good, poor habitat can limit biodiversity and ecosystem function.
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What it shows
- Stability of stream banks and erosion risk
- Quality of riparian margins and shading
- Degree of human modification
- Overall capacity of the stream to support aquatic life
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Streambed Composition (Substrate Composition)
How data is recorded
In the Streambed Composition module, the assessor visually estimates the percentage of the streambed made up of different substrate types: bedrock, boulder, cobble, gravel, sand, and silt/mud. Sliders are used to assign percentages to each category, with the total required to equal 100%. The assessor also records the level of embeddedness, indicating how much coarse material is buried by fine sediment (low, moderate, or high). Site information, GPS coordinates, date, and a streambed photo are included, along with optional notes.
Why this data is collected
Substrate composition strongly influences habitat quality for aquatic invertebrates, fish spawning, and periphyton growth. Excess fine sediment can smother habitats, reduce oxygen exchange, and degrade ecological function.
What it shows
- Balance between coarse and fine sediments
- Evidence of sedimentation from erosion or land use
- Suitability of habitat for benthic organisms
- Physical indicators of degraded or healthy mauri
Important: Excess fine sediment can smother habitats, reduce oxygen exchange, and degrade ecological function.
Rubbish Assessment
How data is recorded
The Rubbish Assessment module records visible rubbish at the site. The assessor selects an overall rubbish abundance category (none, light, moderate, or heavy) and counts items within specific categories such as plastic, metal, glass, organic waste, and other debris. The app automatically calculates a cleanliness score. Site details, GPS coordinates, photos, and optional cleanup notes are also recorded.
Why this data is collected
Rubbish is a direct and visible indicator of human impact on waterways. It can harm wildlife, degrade habitat, and reduce cultural, recreational, and aesthetic values of a stream.
What it shows
- Degree of direct human pollution
- Risks to aquatic life and mahinga kai
- Opportunities for cleanup and community action
- Impacts on cultural wellbeing and mana of the waterway
Stream Flow (Current Velocity and Streamflow)
How data is recorded
Stream flow is assessed using the float method to calculate current velocity. A floating object is timed over a measured distance, and the result is entered into the app. Stream width and average depth are also recorded to estimate discharge. The assessor selects an overall flow condition (dry, trickle, low, moderate, high, or flood) and adds notes about recent rainfall or conditions. Site information, GPS coordinates, and photos are included.
Why this data is collected
Flow controls habitat availability, sediment transport, water quality, and species movement. Changes in flow can strongly influence ecological processes and stream resilience.
What it shows
- Whether flows are sufficient to support aquatic life
- Impacts of abstraction, drought, or flooding
- Relationship between flow and sediment or periphyton patterns
- Overall physical energy of the stream system
Environmental Conditions (rainfall, lunar cycle, weather)
How data is recorded
The Environmental Conditions module records weather and environmental context at the time of assessment. Data such as lunar cycle, air temperature, rainfall (last 24 hours and 7 days), wind speed and direction, cloud cover, and atmospheric pressure are either auto-filled or entered manually. The app also records the lunar phase. Site location and date are included.
Why this data is collected
Environmental conditions influence stream behaviour and help interpret results from other modules. Rainfall and lunar phase can affect flow, sediment movement, fish behaviour, and cultural harvesting practices.
What it shows
- Context for water quality and flow measurements
- Influence of recent weather on stream condition
- Alignment with mātauranga Māori observations (e.g. lunar cycles)
- Temporal factors affecting mauri at the time of assessment
Mahinga Kai Cultural Assessment
From December 2025, mahinga kai is a compulsory value under the National Policy Statement for Freshwater Management 2020 (NPS-FM 2020).
Regional councils are required to work with tangata whenua to identify and provide for this value in their planning instruments.
How data is recorded
The Mahinga Kai module documents cultural values rather than numerical measurements. Assessors record site information and then add narrative information under headings such as mātauranga Māori, historical use, rāhui status, kaitiaki contacts, cultural significance, and restoration aspirations. Cultural site photos can also be uploaded.
Why this data is collected
Mahinga kai is central to Māori relationships with freshwater. This module ensures that cultural knowledge, values, and aspirations are captured alongside scientific data, rather than being treated as separate or secondary.
What it shows
- Cultural importance and traditional use of the waterway
- Presence or loss of mahinga kai resources
- Community and iwi aspirations for restoration
- Cultural dimension of mauri that cannot be measured scientifically
Cultural Integration: This module ensures that cultural knowledge, values, and aspirations are captured alongside scientific data, rather than being treated as separate or secondary.
Site Information – Explanation
Site Name
This is the name used to identify the location where the stream assessment is carried out. It should be clear and specific so the site can be easily found again in the future. This often includes the stream name and access point (for example, Blue Creek – North Access).
Assessor Name
This records the name of the person or group who completed the assessment. It is important for accountability and allows results to be traced back to the observer if clarification or follow-up is needed.
Date
This records the day the assessment was completed. Stream conditions can change over time due to weather, seasons, or land use, so the date is essential for comparing results between different surveys.
GPS Coordinates (Latitude and Longitude)
These record the exact geographic location of the assessment site. GPS coordinates ensure the site can be accurately mapped, revisited, and compared with other monitoring locations. This is especially important for long-term monitoring and reporting.
Attach Stream Photo
This allows a photograph of the stream to be uploaded. Photos provide visual evidence of site conditions such as water clarity, vegetation, bank stability, and flow. They also help support written observations and allow future comparisons.
What happens with my data?
When you complete an assessment in the Mauri Compass Stream Health Assessment app, the information you enter (measurements, observations, site details, and photos) is saved locally within the app. This allows you to review, export, or share the results without needing to re-enter the data. The data is used to create a summary of stream health for that site and time, which can then be shared as a report.
Download PDF Report vs Email Report – What’s the difference?
Download PDF Report
When you select Download PDF, the app generates a PDF copy of your completed assessment and saves it directly to your device. This option is useful if you want to:
- Submit the report as part of an assignment
- Upload it to another platform (e.g. Google Drive or Teams)
- Print a hard copy
- Keep a personal record of the assessment
The PDF does not automatically share your data with anyone else unless you choose to send or upload it yourself.
Email Report
When you select Email Report, the app sends the completed assessment as a report to a chosen email address (for example, a teacher, project lead, or kaitiaki). This option is useful if you want to:
- Share results directly with others
- Submit the assessment without downloading files
- Support collaborative monitoring or reporting
The data is shared only with the email recipient you select.
The default setting is to email to Ian Ruru. His team can help you interpret and analyse your results. Simply remove ianruru@gmail.com if you are happy to analyse the results yourself. Kia kaha!
Tools Commonly Used
A basic eel dissection kit usually includes:
Scalpel
For making precise incisions along the body cavity
Dissecting Scissors
To open muscle and connective tissue safely
Forceps (Tweezers)
For lifting and separating organs
Dissecting Tray/Board
To secure the eel during dissection
Gloves and Eye Protection
For hygiene and safety
Probe or Ruler
For pointing out structures and measuring organs
External Organs and Features
The external features of a New Zealand eel (tuna) provide immediate information about its health, behaviour, and the condition of the river it lives in. These observations are often made before dissection and help build a picture of overall environmental quality.
Skin and Slime Layer
Eels have thick, smooth skin covered in a mucus (slime) layer that protects them from disease, parasites, and injury. A healthy eel will feel slippery and look evenly coloured. Dry skin, wounds, or excess mucus can indicate stress, poor water quality, or exposure to pollutants and sediment.
Colouration
Body colour varies naturally, but strong, even colour usually indicates good health. Darkened backs with lighter bellies are typical. Very pale, blotchy, or dull colouring can suggest illness, low oxygen levels, or poor habitat conditions. Silvering of the belly indicates a mature eel preparing for migration.
Eyes
Clear, bright eyes suggest good health. Cloudy, damaged, or sunken eyes may indicate disease, physical injury, or prolonged exposure to poor water quality.
Fins
Eels have a continuous dorsal, ventral, and anal fin. These fins should be intact and flexible. Torn or eroded fins can result from pollution, abrasive substrates, barriers, or high sediment levels within the river.
Gills (External View)
When visible, healthy gills appear red and moist. Pale, brown, or mucus-covered gills can suggest low dissolved oxygen, sediment clogging, or chemical irritation.
Mouth and Jaws
The mouth and jaw alignment show feeding ability. Deformities, sores, or damage may indicate disease or difficulty feeding, often linked to environmental stress or reduced prey availability.
Vent (Anus)
The vent provides clues about maturity and health. Swelling, redness, or discharge may indicate infection or internal stress, while a normal vent suggests good overall condition.
Body Condition and Shape
A well-rounded body indicates good nutrition and habitat quality.
Thin or emaciated eels may reflect poor food supply, overcrowding, or degraded river conditions.
Organs Identified and What They Tell Us
Liver
The liver is usually large and dark. A healthy liver should be smooth and firm. Pale colouring, swelling, or spots can indicate disease, stress, or exposure to pollutants such as heavy metals or agricultural chemicals.
Stomach and Intestines
These organs show what the eel has been feeding on (e.g. insects, fish, kōura). Full, well-developed digestive organs suggest good food availability, while empty or damaged guts may indicate poor habitat quality or limited prey.
Gonads (Reproductive Organs)
The size and development of the gonads help determine the eel's sex and life stage. Enlarged gonads indicate a migrating "silver eel" preparing to leave freshwater to spawn, while small gonads suggest a resident feeding stage. Female NZ eel gonads (ovaries) are large, thick, and granular, often cream to yellow in colour and taking up much of the body cavity. Male gonads (testes) are thin, flat, smooth, ribbon-like, pale or translucent, and much smaller and harder to see.
Picture of Male Gonads.
Swim Bladder
This gas-filled organ helps the eel control buoyancy. Damage, parasites, or cloudiness can reduce swimming efficiency and may reflect poor water quality or parasite presence in the river.
Kidneys
Kidneys regulate salts and remove waste. Discolouration or abnormal size can suggest long-term stress from poor water chemistry, such as high conductivity or contaminants.
Heart and Gills (If Examined)
The heart and gills indicate oxygen transport and respiration. Healthy gills are bright red and clean; pale or damaged gills may point to low dissolved oxygen, sedimentation, or chemical irritation in the stream.
1. Water Quality Probe
How it was used
The probe was calibrated prior to use and then placed into flowing sections of the stream at mid-depth to avoid surface warming effects and sediment disturbance. Readings were allowed to stabilise before recording temperature, pH, dissolved oxygen (DO), and conductivity. Measurements were taken at multiple points to account for small-scale variation in water chemistry.
Why it was used
Water quality strongly influences eel physiology and habitat suitability. While eels are more tolerant than many native fish species, prolonged exposure to poor water quality can reduce growth rates, increase stress, and limit successful migration. Measuring these parameters allows environmental conditions to be linked directly to eel presence, size, and condition.
What it helps show
pH
Optimal range for eels: ~6.5–8.0
Poor / stressful: < 6.0 (acidic) or > 8.5 (alkaline)
Low pH can damage gill tissue and disrupt ion balance, while high pH can increase ammonia toxicity.
Conductivity
Healthy freshwater range: ~50–300 µS/cm
Elevated / poor: > 400–500 µS/cm
High conductivity often indicates nutrient enrichment, urban runoff, or salinity intrusion, which can degrade eel habitat quality.
Dissolved Oxygen (DO)
Good: > 6 mg/L
Poor: < 4 mg/L
Although eels can tolerate low oxygen better than most fish, persistently low DO increases stress and reduces activity.
Temperature (C)
Water temperature was measured using the water quality probe, which was placed at mid-depth in flowing water and allowed to stabilise before recording. Temperature was measured alongside other water quality variables for consistency.
Temperature influences eel metabolism, activity, and growth, as eels rely on surrounding water to regulate body processes. It also affects dissolved oxygen levels and food availability.
- Optimal range: ~12–20°C
- Stressful conditions: < 8°C or > 20°C
Water temperature helps indicate whether a stream provides suitable conditions for eel feeding, breathing,movement, and long-term habitat quality.
Together, these measurements indicate whether the stream provides a chemically suitable environment for sustaining eel populations and help identify possible catchment scale impacts.
2. Fyke Net (Hīnaki)
How it was used
The fyke net (hīnaki) was set overnight with the entrance facing downstream or perpendicular, positioned along natural eel movement pathways such as stream margins and deeper channels. Nets were checked promptly to minimise stress. Captured eels were identified to species, measured for length, and assessed for condition before release.
Why it was used
Fyke nets are effective because they exploit eel movement behaviour rather than relying on attraction or bait. The hīnaki also reflects long-standing Māori knowledge of eel ecology, reinforcing culturally informed monitoring practices.
What it helps show (specific data collected)
- Presence and abundance of eels in the stream
- Size and age structure, indicating whether the stream supports juveniles, adults, or migrants
- Species composition, supporting biodiversity assessment
- Movement patterns, suggesting how eels use different parts of the habitat
3. Dissection Kit
How it was used
The dissection kit was used to carefully examine eel specimens under controlled conditions. External features such as body condition, skin integrity, and fin damage were recorded. Internal examination focused on the digestive tract and major organs to assess feeding status and overall health.
What it helps show (specific indicators)
Stomach contents
Indicates recent feeding success and available prey
Fat reserves and organ condition
Reflect nutritional status and habitat quality
Signs of disease or parasites
May indicate environmental stress or degraded conditions
Developmental stage
Supports understanding of whether the habitat is used for growth, residency, or migration
Why it was used
Dissection allows direct observation of biological indicators that reflect both environmental quality and eel life history. Internal condition can reveal long-term stressors that are not immediately apparent from water quality data alone.
4. Humane Handling (Clove oil)
Alternative method – Ice
An alternative humane method is placing the eel into an ice slurry (a mix of ice and water), which gradually lowers body temperature and slows metabolism. This reduces activity and responsiveness, leading to loss of consciousness with minimal stress when performed correctly.
An alternative humane method is placing the eel into an ice slurry (a mix of ice and water), which gradually lowers body temperature and slows metabolism. This reduces activity and responsiveness, leading to loss of consciousness with minimal stress when performed correctly.
What it helps show
- Stress minimisation
Reduces physiological stress responses such as excessive movement, mucus loss, and oxygen demand during handling.
- Ethical euthanasia or sedation
Ensures the eel loses consciousness rapidly and painlessly before any invasive procedures, meeting animal welfare standards.
- Reliable biological observations
Calm, sedated eels allow more accurate assessment of size, condition, and internal organs without stress-related distortion.
- Consistency across samples
Standardised sedation improves comparability between specimens by limiting handling-induced variation.
How it's used
Clove oil (eugenol) was prepared as a dilute solution and added to a container of stream water. Eels were gently placed into the solution and monitored closely. Within a short period, the eel became sedated and unresponsive to external stimuli, indicating loss of consciousness. For euthanasia, the eel remained in the solution for a sufficient duration to ensure death before any dissection occurred. Throughout the process, handling was minimised and monitoring was continuous to ensure the procedure was humane and effective.
Why it's used
Clove oil is a widely accepted, humane anaesthetic for fish and eels. It is effective at low concentrations, acts quickly, and causes minimal distress when used correctly. Using clove oil aligns with ethical research practices, animal welfare guidelines, and kaupapa Māori principles of respect for living organisms. Humane handling ensures that data collected reflects true environmental and biological conditions rather than stress responses caused by poor handling.
5. Environmental DNA (eDNA) Sampling (OPTIONAL)
How it was used
Water samples were collected upstream of physical sampling areas to avoid contamination from captured or handled eels. Sterile bottles were used, and samples were sealed immediately. Samples were filtered and analysed in a laboratory to amplify eel-specific DNA markers.
Why it was used
eDNA is particularly effective for detecting species that are elusive, nocturnal, or present at low densities. It complements physical capture methods by reducing sampling bias and eliminating the need to disturb habitat or organisms during detection.
What it helps show (specific outcomes)
- Confirms presence or absence of eels within the catchment
- Detects eels even if they are burrowed, inactive, or avoiding traps
- Provides evidence of habitat use across time, as DNA can persist in water for days
- Helps validate or explain fyke net results (e.g., eDNA present but no capture suggests low abundance or trap avoidance)
6. Mauri Compass App
How it was used
The Mauri Compass App was used in the field to record all observations, measurements, and monitoring results in real time. Data collected from the water quality probe, eDNA sampling, fyke netting, and visual site observations were entered directly into the app during the assessment. The app guided the assessment process by prompting users to consider multiple environmental attributes rather than focusing on a single indicator.
Why it was used
The Mauri Compass App is designed to support holistic environmental assessment grounded in Te Ao Māori. Rather than relying solely on numerical data, the app integrates scientific measurements with cultural and observational indicators. This ensures that decision making reflects not just physical water quality, but also ecosystem health, mahinga kai values, and the wellbeing of people connected to the site.
Using the app in real time reduces data loss, improves accuracy, and allows immediate reflection on site conditions. It also encourages consistent assessment between sites and observers.
What it helps show
The Mauri Compass App helps interpret environmental data within a holistic framework of mauri . By combining quantitative measurements with qualitative observations, the app provides an overall indication of ecosystem health.
Specifically, it helps to:
- Assess whether the mauri of the waterway is being sustained, enhanced, or degraded
- Identify trade offs between environmental health, cultural values, and human use
- Support culturally informed decision-making for freshwater management
- Communicate results clearly to communities, kaitiaki, and decision makers
7. Water Clarity Tube
How it was measured
Water clarity was measured using a clarity tube. Stream water was poured into the tube until the black-and-white target at the base became visible. The depth at which the target could be seen was recorded as the clarity measurement.
Why it was measured
Clarity is an important indicator of sediment levels and disturbance within the catchment. While eels are tolerant of lower clarity than many fish species, excessive suspended sediment can smother habitat, reduce invertebrate abundance, and affect gill function.
What it helps show
- Good clarity: typically > 1.0 m
- Moderate clarity: 0.5–1.0 m
- Poor clarity: < 0.5 m
Low clarity often reflects upstream erosion, stock access, or runoff following rainfall. Reduced clarity can limit prey availability and degrade benthic habitat used by eels for shelter and feeding.
8. Stream Velocity
How it was measured
Stream velocity was measured by marking a 10-metre section of the stream. A floating object such as a lemon or orange was released at the upstream point and the time taken to travel the 10 metres was recorded using a stopwatch. This was repeated multiple times and an average time was calculated. Velocity was then estimated using the formula:
Velocity = Distance ÷ Time
Why it was measured
Stream velocity influences eel movement, energy expenditure, and habitat use. Eels prefer slow to moderate flows where they can move efficiently, shelter behind structures, and forage effectively. Velocity also affects sediment transport and channel stability.
What it helps show
- Low velocity: suitable for juvenile and resident eels, providing refuge and feeding areas
- Moderate velocity: supports migration and oxygenation
- High velocity: may limit eel movement and reduce habitat availability
Velocity measurements help explain eel distribution within the stream and provide context for fyke net placement and capture success.