Assessment period: 16–17 December 2025
He karakia kia uru ki ngā taiao
Ka urua te tāhū nui o Rangi
Ka urua te nuku roa o Papa
Tēnei te toki whakaaraara
He toki mā te tangata ora
Huia mai ki ahau
Huia mai ki te katoa
He mauri tōnui
Whakaputahia ki te whaiao,
ki te ao mārama!
Whano, whano!
Haeremai te toki
Haumi ē!
Hui ē!
Tāiki ē!
Nā Herea Winitana
Freshwater stream health is best understood through the integration of multiple indicators that reflect chemical, biological, and physical conditions. No single metric can adequately capture ecosystem condition in isolation.
This assessment applies the Mauri Compass – Stream Health Monitoring and Assessment Kit (SHMAK) to evaluate stream health using four complementary components:
(with emphasis on tuna / longfin eel)
(pH, temperature, conductivity)
(MCI / QMCI)
(velocity and discharge)
(mahi ngā kai)
(karakia)
Together, these indicators provide a robust picture of ecological integrity, habitat suitability, and mauri across the stream system.
Assessments were undertaken across multiple sites between 14 and 17 December 2025.
Conducted at Sites 2–5 using baited methods suited to nocturnal and cryptic species.
Collected at Sites 1–5 using in-situ field instruments.
Undertaken at two locations, including Site 1 and an additional site with unspecified location.
Recorded at the Waiting Bridge site using SHMAK flow assessment protocols.
All data were interpreted using SHMAK and Mauri Compass guidelines aligned with New Zealand freshwater standards.
Across all fish survey sites (Sites 2–5), longfin eel (Anguilla dieffenbachii) was the only species recorded.
Nine adult longfin eels were captured at Site 2.
- Measured lengths ranged from approximately 41 cm to 97 cm, including at least one very large individual.
- Abundance was classified as common.
- The presence of multiple large-bodied adults suggests long-term habitat stability and sustained access to migration pathways.
Nine adult eels were also recorded at Site 3, with lengths ranging from approximately 30 cm to 55 cm.
While individuals were generally smaller than those at Site 2, eels at this site were described as notably lively and active, suggesting favourable local habitat conditions, such as good oxygen availability and effective refuge habitat.
Site 4 recorded the highest abundance, with eleven adult eels measured between approximately 39 cm and 58 cm.
Despite high numbers, many individuals appeared lethargic, indicating that although the site remains accessible and capable of supporting eels, localised stressors may be influencing fish condition.
This may reflect sediment accumulation, reduced flow variability, or organic enrichment rather than chemical pollution.
Only one adult eel was recorded at Site 5, measuring approximately 64 cm.
Water at this site was described as significantly more turbid.
Under SHMAK guidelines, the presence of a single native species corresponds to a "fair" ecological condition.
However, the consistent occurrence of adult longfin eels—a long-lived, nationally threatened taonga species—indicates that the stream continues to function as important habitat.
Spatial differences in abundance and behaviour strongly suggest that physical habitat conditions, rather than water chemistry, are the primary drivers shaping eel distribution.
Water quality was assessed at Sites 1–5 and showed consistently favourable results across the catchment.
Ranged from 6.97 to 7.18, well within optimal ranges for native freshwater fauna.
Ranged from 16.3°C to 19.5°C, remaining below stress thresholds and supportive of high dissolved oxygen levels.
Values ranged from 72 to 142 µS/cm, with most sites classified as pristine and no evidence of significant pollution.
One MCI assessment recorded a score of 6.7, classifying the site as excellent.
Two taxa were identified:
- Green stonefly (Stenoperla) – score 10, abundance 1
- Dolomedes spider – score 5, abundance 2–5
Stoneflies are highly sensitive to pollution and habitat degradation, and their presence strongly indicates pristine water quality and stable habitat conditions. Despite low taxa richness, the dominance of sensitive taxa supports the high MCI score.
At Site 1, the MCI score was 4.3, classifying the site as poor under QMCI guidelines.
Two taxa were recorded:
- Freshwater shrimp (Paratya) – abundant (21+ individuals)
- Flat spiral snail (Gyraulus) – moderate abundance
Both species are relatively tolerant of environmental stress, and their dominance suggests reduced habitat quality. This result contrasts with the strong water chemistry at Site 1, indicating that habitat structure, sedimentation, or flow disturbance may be limiting invertebrate diversity despite acceptable chemical conditions.
Flow measurements were conducted at Waiting Bridge, recording a mean velocity of 1.001 m/s and a discharge of approximately 2.0 m³/s (2002 L/s).
metres per second
cubic metres per second (2002 L/s)
High flows can reduce habitat stability, dislodge macroinvertebrates, and limit refuge availability for fish, particularly in simplified channels.
When considered together, results show a system with excellent water chemistry, strong native fish presence, but variable biological responses driven by physical habitat and flow conditions.
indicating maintained connectivity.
suggesting localised habitat degradation rather than catchment-wide pollution.
From a Mauri Compass perspective, the stream retains strong mauri overall.
This integrated SHMAK assessment demonstrates that the stream system maintains high water quality, and mauri, and continued support for taonga species, particularly longfin eel.
Fish Communities, Water Quality, Macroinvertebrates, and Flow Conditions Using the Mauri Compass – SHMAK Framework