How to Use This Site
Interactive Sites Map
Click any marker to view site details including water quality, species, and eel counts
Water Quality Tab
View pH, temperature, and water clarity readings from all 8 sites
Eel Data Tab
Individual eel measurements – length, weight, and size class for each tuna caught
Species Summary Tab
All native fish and invertebrates found at each site
Field Calculator
Estimate weight from length (or vice versa) – handy backup when batteries fail
Site Photo Gallery
Field photos from each site with extra species notes
Export Report
Download survey data as Markdown for Word/editing
360° Panorama Viewer
Explore all 8 sites with immersive panoramas, sci-fi scan animation & 2020 vs 2026 comparison
Our Survey Team
Te Kura o Uruti
Site 3 – Uruti School
Urenui Divers Club
Team briefing before field work
Urenui River Bridge 176
"Protect our streams"
Survey Sites Map
Data from Aqua TROLL 600 multi-parameter sonde (VuSitu)
| Site | pH | Temp (°C) | Clarity (cm) | DO (mg/L) | DO Sat (%) | Turbidity (NTU) | Conductivity (µS/cm) | ORP (mV) |
|---|---|---|---|---|---|---|---|---|
| 1. McClutchies | 6.58 | 20.12 | 44.5 | 8.95 | 98.44% | 13.66 | 103.79 | 203.16 |
| 2. Mimi / Mangamaio | 6.63 | 23.26 | 35.5 | 8.76 | 102.72% | 36.89 | 111.13 | 234.24 |
| 3. Uruti School | 8.17 | 19.57 | 45.5 | 8.68 | 94.71% | 9.82 | 60.28 | 162.31 |
| 4. Mangahia | 6.53 | 21.9 | 48 | 9.94 | 113.71% | 152.52 | 36.87 | 214.29 |
| 5. Avenue Road | 6.65 | 19.97 | 94 | 9.1 | 99.98% | 2.74 | 120.9 | 229.08 |
| 6. Okoki Pa | 6.59 | 21.16 | 28 | 8.7 | 97.86% | 23.02 | 94.4 | 230.19 |
| 7. Okoki Bridge | 6.46 | 20.72 | 36 | 8.77 | 97.78% | 18.49 | 91.73 | 223.36 |
| 8. Kaka Road | 6.62 | 20.83 | 55.5 | 8.37 | 93.77% | 9.72 | 109.96 | 226.89 |
Parameter Key:
pH: Acidity/alkalinity. Healthy range: 6.5-8.5. Most NZ streams: 6.5-7.5.
Temperature: Water temp in °C. Eels prefer 15-25°C.
Clarity: Visibility depth in cm (clarity tube). Higher = clearer water.
DO (Dissolved Oxygen): Oxygen in water. Healthy: 6-10 mg/L. Below 5 mg/L stresses fish.
DO Saturation: % of max oxygen capacity. 80-120% is healthy.
Turbidity: Water cloudiness in NTU. <10 = very clear, 10-50 = moderate, >50 = turbid.
Conductivity: Dissolved minerals in µS/cm. NZ streams typically 50-200 µS/cm.
ORP: Oxidation-Reduction Potential in mV. Healthy streams: 150-300 mV. Indicates water's ability to break down contaminants.
2020 vs 2026 Survey Comparison
Comparing data from the February 2020 Mauri Compass assessment with the January 2026 survey.View 2020 Report
2020 Total Eels
~32
across 8 sites
2026 Total Eels
139
across 8 sites
Increase
+334%
more eels captured
Number of eels captured at each site in 2020 vs 2026
- 2020
- 2026
Significant increases observed at most sites, particularly Okoki Bridge (3 to 41), Mimi/Mangamaio (3 to 18), and Okoki Pa (1 to 17).
Clarity tube measurements (cm) - higher values indicate clearer water
- 2020
- 2026
Avenue Road showed improved clarity (58 to 94cm). Most sites had reduced clarity in 2026, likely due to 61.2mm rainfall in the prior 7 days.
Sites 1-4: McClutchies, Mimi/Mangamaio, Uruti School, Mangahia
- Pre-European
- 2020
- 2026 (Estimates)
59 eels caught across 4 sites. Strong biodiversity with 5 native species including Banded Kokopu and Inanga.
Key Finding: The 2026 estimates show improvement in tuna-focused indicators compared to 2020, with abundance increasing significantly (particularly in Urenui catchment). However, all indicators remain well below pre-European levels, highlighting the ongoing need for restoration efforts. Note: 2026 values are estimates pending formal Mauri Compass assessment.
Eel Data Analysis
Total eels captured at each sampling location
Okoki Bridge recorded the highest catch (41 eels), followed by Mangahia and Mimi/Mangamaio (18 each). Total: 139 eels across 8 sites.
- Mangahia
- Uruti School
- Mimi
- Kaka Road
- McClutchies
- Okoki Pa
- Okoki Bridge
- Avenue Road
- Elver
- Sub-adult
- Adult
- Large Adult
Field Calculator
Eel Length-Weight Estimator
A helpful backup tool when scale batteries fail or the tape measure is forgotten. Based on regression analysis of our survey data (R² = 86%).
Formula
Weight (g) = 0.155 × Length2.1
Note: This provides an approximation. Actual weights vary based on eel condition and species.
Enter a measurement to estimate the other:
Site Photo Gallery
1McClutchies(4 fish species, 1 invertebrate types)
Riaki's Net
10+ shrimps observed
Kahu's Net
9 shrimps observed
2Mimi / Mangamaio(6 fish species, 1 invertebrate types)
Riaki's Net
10+ shrimps, Banded Kokopu found
Kahu's Net
8 shrimps, 1 dead Shortfin
3Uruti School(3 fish species, 0 invertebrate types)
Riaki's Net
120cm large adult eel caught
Kahu's Net
10 healthy eels measured
4Mangahia(2 fish species, 3 invertebrate types)
Riaki's Net
14 eels from upstream net
Kahu's Net
2 eels + 2 elvers, mayflies, damselflies
8Kaka Road(1 fish species, 1 invertebrate types)
Riaki's Net
6 eels from downstream, shrimps present
Kahu's Net
5 eels from upstream, 12 shrimps
Field Work Gallery
Deep Water Sampling
Checking fyke nets in deeper pools
Mangahia Stream
Rangatahi deploying G-minnow traps
Water Clarity Testing
Wānanga training - visual clarity tube method
Site Briefing
Data recording app training in the field
Seine Netting
Team working together in turbid water
Gear Logistics
Loading fyke nets and equipment
Rangatahi Discovery
Young scientists examining inanga catch - Day 2
Survey Team
Methodology Training
Team training session covering survey protocols, fish handling, and data recording procedures. 19 January 2026.
Team Assembly
Survey team assembled at Urenui Divers Club before deploying to field sites. 19 January 2026.
Survey Methodology
Sampling Gear
- Fyke Nets (2 per site): Double-winged fyke nets deployed upstream and downstream to capture eels and larger fish moving through the stream
- G-Minnow Traps: Baited traps targeting smaller species including juvenile fish, kōura (freshwater crayfish), and invertebrates
- Seine Net: Used at selected sites for active sampling of shallow margins
- Soak Time: Overnight deployment from late afternoon (4-6pm) to morning retrieval (8-10am), approximately 14-18 hours
Water Quality Monitoring
- Aqua TROLL 600: Multi-parameter sonde measuring pH, temperature, dissolved oxygen, conductivity, turbidity, and ORP
- Clarity Tube: Visual clarity assessment using standardised SHMAK black disc method
- VuSitu App: Real-time data logging and GPS tagging of all measurements
Fish Assessment
- Species ID: Visual identification of all native and introduced species
- Measurements: Total length (cm) using measuring board, weight (g) using digital scales
- Photo Documentation: Representative specimens photographed for verification
Environmental Context
- Lunar Phase: New Moon selected for optimal eel activity (dark nights)
- Tidal Influence: Rising tide conditions recorded for coastal-connected sites
- Weather: Temperature, rainfall (7-day antecedent), wind, and cloud cover
- Habitat Notes: Riparian vegetation, substrate type, and flow conditions
Assessment Framework
Data collected using the Mauri Compass framework, integrating mātauranga Māori with scientific monitoring. The Stream Health Monitoring and Assessment Kit (SHMAK) protocols ensure data quality and comparability with regional council monitoring programmes.