Water Turbidity

AUS-AMR-AQU-WTU General High confidence

Benchmark Value

2 NTU

Direction: Lower is desirable ↓

Form: LowerThreshold

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 15 benchmarks together — the OptimalRange form drives the primary score, while 14 guard(s) constrain the result.

Contributing Benchmarks

OptimalRange Primary MaximumOnly Guard OptimalRange Guard Point Guard MaximumOnly Guard MaximumOnly Guard MaximumOnly Guard MaximumOnly Guard OptimalRange Guard MaximumOnly Guard Point Guard LowerThreshold Guard OptimalRange Guard MaximumOnly Guard MaximumOnly Guard

Evidence & Context

Therefore, a lower critical threshold exists, likely in the range of < 2 NTU, below which negative physiological effects may occur.

Metric Definition:

Lower critical threshold of water turbidity below which negative physiological effects may occur in some cultured species.

Benchmark Definition:

Lower critical turbidity threshold below which some cultured species may experience physiological stress in arid mountain aquaculture systems.

Justification:

Research shows fish species adapted to turbid environments experience stress below this turbidity level.

Sources (2)

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 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, Government

Low turbidity in recirculating aquaculture systems (RAS) reduces feeding behavior and increases stress-related physiological parameters in pikeperch (Sander lucioperca) during grow-out

View Source

Supporting Sources (2)

Additional references from the underlying research that informed this benchmark.

Best Pratice Environmental Management Guidelines for ... - VFA, accessed July 20, 2025,

Direct Evidence Government

Best Pratice Environmental Management Guidelines for ... - VFA

View Source

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

Regulatory Framework Government

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

View Source

Context

Region Australia
Biome Arid Mountain Ranges & Uplands
Land Use Aquaculture
Assessment Not Stated
Evidence Type DegradationThreshold

Lifecycle

Status Active
Version 1
Effective From 4 Jun 2026

Notes

A lower critical threshold of < 2 NTU may induce stress in some species adapted to turbid conditions, compromising animal welfare. AssessmentContext defaulted to 'Not Stated' because the source document did not state one.

Related Benchmarks

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