Water Nitrate

AUS-AMR-AQU-WNI General Moderate confidence

Benchmark Value

1 mg/L

Direction: Lower is desirable ↓

Form: MaximumOnly

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 4 benchmarks together — the Point form drives the primary score, while 3 guard(s) constrain the result.

Contributing Benchmarks

Point Primary MaximumOnly Guard MaximumOnly Guard MaximumOnly Guard

Evidence & Context

Based on this triangulation of evidence, a reference value of <1.0 mg/L of nitrate (NO3−) is proposed.

Metric Definition:

Water nitrate concentration in the receiving environment of freshwater aquaculture operations in Australia's Arid Mountain Ranges & Uplands biome.

Benchmark Definition:

This benchmark represents the maximum nitrate concentration in water that supports sustainable aquaculture while protecting naturally low-nutrient aquatic ecosystems in the Arid Mountain Ranges & Uplands biome.

Justification:

This benchmark is a proxy derived from reference sites in the Flinders Ranges, representing a high-health state that avoids the "nutrient enrichment" identified as causing ecological degradation. It is supported by quantitative data from healthy, fish-bearing spring pools in the same region.

Sources (2)

(PDF) Water quality parameters and population characteristics for the Flinders Ranges Gudgeon - ResearchGate

Toxicant default guideline values for aquatic ecosystem protection ...

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Preview of SA Arid Lands Landscape Regional Summary 2022 Aquatic ..., accessed July 30, 2025,

SA Arid Lands Landscape Regional Summary 2022 Aquatic ..., accessed July 30, 2025, Government

(PDF) Effects of increasing salinity on freshwater ecosystems in ..., accessed July 31, 2025,

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Supporting Sources (1)

Additional references from the underlying research that informed this benchmark.

Preview of Establishment of reference conditions and trigger values for chemical, physical and micro-biological indicators in New Zealand streams and rivers - Ministry for the Environment, accessed August 11, 2025,

Establishment of reference conditions and trigger values for chemical, physical and micro-biological indicators in New Zealand streams and rivers - Ministry for the Environment, accessed August 11, 2025,

Direct Evidence Journal

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

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Context

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

Lifecycle

Status Superseded
Version 1
Effective From 19 Mar 2026
Effective To 19 Mar 2026

Notes

The benchmark reflects a management philosophy focused on containment and impact minimization in naturally oligotrophic aquatic ecosystems. The value is consistent with ecological assessments and ANZG guidelines for toxicity thresholds dependent on water hardness.

Related Benchmarks

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