Water Turbidity

AUS-AMR-AQU-WTU General Moderate confidence

Benchmark Value

25 NTU
Thresholds: Lower: —, Upper: 25
Direction: Higher is desirable ↑
Form: UpperThreshold

Scoring Curve

This curve shows how a field measurement for this indicator would score across all available benchmark forms in this context. The scoring engine uses 20 benchmarks together — the OptimalRange form drives the primary score, while 19 guard(s) constrain the result.

Contributing Benchmarks

OptimalRange Primary LowerThreshold Guard UpperThreshold Guard Point Guard UpperThreshold Guard MaximumOnly Guard LowerThreshold Guard OptimalRange Guard OptimalRange Guard LowerThreshold Guard MaximumOnly Guard UpperThreshold Guard MaximumOnly Guard OptimalRange Guard MinimumOnly Guard Point Guard LowerThreshold Guard OptimalRange Guard UpperThreshold Guard MaximumOnly Guard

Evidence & Context

A turbidity measurement exceeding > 25 NTU indicates that the system is no longer functioning as designed and requires immediate corrective action to prevent catastrophic stock losses.

Metric Definition:

Upper detrimental turbidity threshold indicating system malfunction and degraded state in aquaculture.

Benchmark Definition:

Upper turbidity threshold beyond which aquaculture system health is compromised.

Justification:

Exceeding this turbidity level signals filter failure, overfeeding, or other management issues leading to degraded conditions.

Sources (1)

Preview of Water quality guidelines - Queensland Environment Department, accessed August 1, 2025,
Water quality guidelines - Queensland Environment Department, accessed August 1, 2025, Government

Australian and New Zealand Guidelines for Fresh and Marine Water Quality (2000)

View Source

Supporting Sources (3)

Additional references from the underlying research that informed this benchmark.

Preview of Best Pratice Environmental Management Guidelines for ... - VFA, accessed July 20, 2025,
Best Pratice Environmental Management Guidelines for ... - VFA, accessed July 20, 2025,
Direct Evidence Government

NSW Land Based Sustainable Aquaculture Strategy, accessed July 21, 2025

View Source
Preview of Effects of turbidity, temperature and predation cue on the stress response of juvenile delta smelt | Conservation Physiology | Oxford Academic
Effects of turbidity, temperature and predation cue on the stress response of juvenile delta smelt | Conservation Physiology | Oxford Academic
Contextual Support Journal

Effects of turbidity, temperature and predation cue on the stress response of juvenile delta smelt | Conservation Physiology | Oxford Academic

View Source
Preview of Water quality for primary industries, accessed July 30, 2025,
Water quality for primary industries, accessed July 30, 2025,
Direct Evidence Government

Development of regional water quality and catchment guidelines for the conservation of aquatic ecosystems - NSW Environment Protection Authority

View Source

Context

  • Region Australia
  • Biome Arid Mountain Ranges & Uplands
  • Land Use Aquaculture
  • Assessment Pristine Reference
  • Evidence Type DegradationThreshold

Lifecycle

  • Status Active
  • Version 1
  • Effective From 19 Mar 2026

Notes

This threshold is a critical management action trigger to prevent stock losses.

Related Benchmarks

Other benchmarks in the AUS-AMR-AQU-WTU family.

3.9 NTU High
Aquaculture · Pristine Reference
Point Active v1
2 NTU Moderate
Aquaculture · Pristine Reference
LowerThreshold Active v1
— NTU Moderate
Aquaculture · Pristine Reference
OptimalRange Active v1