Water Nitrate — Benchmark Detail

Benchmark Value

21.6 mg/L

Direction: Lower is desirable ↓

Form: Point

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 10 benchmarks together — the OptimalRange form drives the primary score, while 9 guard(s) constrain the result.

Contributing Benchmarks

OptimalRange Primary MaximumOnly Guard MaximumOnly Guard MinimumOnly Guard Point Guard MaximumOnly Guard Point Guard MaximumOnly Guard Point Guard MaximumOnly Guard

Evidence & Context

The corrected DGV for 99% protection is 21.6 mg/L of nitrate (as NO3−).

Metric Definition:

Nitrate concentration threshold for 99% species protection according to ANZG guidelines.

Benchmark Definition:

This benchmark defines the regulatory toxicity threshold for nitrate concentration in water to protect 99% of aquatic species in tropical and subtropical rainforest aquaculture environments.

Justification:

This value is based on the Australian and New Zealand Guidelines for Fresh and Marine Water Quality (ANZG) for 99% species protection.

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 (10)

Additional references from the underlying research that informed this benchmark.

Altered water flows and quality | Wet Tropics Management Authority, accessed July 18, 2025,

Contextual Support Government

Release of water quality report for Norfolk Island, accessed July 27, 2025

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Declining water quality - Great Barrier Reef Marine Park Authority, accessed August 1, 2025

Contextual Support Government

Monitoring wetland water quality related to livestock grazing in amphibian habitats - PMC, accessed July 25, 2025,

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Industry | Australia state of the environment 2021

Contextual Support Journal

Industry | Australia state of the environment 2021

View Source

Memorandum - Nitrate guideline values in ANZECC 2000, accessed August 8, 2025

Contextual Support Journal

Hickey, C. (2002). Nitrate guideline values in ANZECC 2000. Memorandum MFE02237 prepared for Ministry for the Environment (New Zealand). NIWA Client Report: HAM2002-126.

View Source

Nitrate guidelines values in ANZECC 2000 - Ministry for the Environment, accessed August 12, 2025

Regulatory Framework Government

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

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Queensland Aquaculture Strategy 2024–2034, accessed August 1, 2025,

Contextual Support Government

land and water | Queensland Government

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Review of Nutrient Release from Aquaculture ... - Griffith University, accessed August 1, 2025

Direct Evidence Journal

Review of Nutrient Release from Aquaculture Activities Final Report - Griffith University

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Toxicant default guideline values for aquatic ecosystem protection ...

Contextual Support

Water Quality Objectives - Murray River catchment (NSW)

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Water quality guidelines - Queensland Environment Department, accessed August 4, 2025,

Contextual Support Journal

Seasonal changes in water quality and macrophytes and the ...

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WQIP - Water Quality Improvement Plan - Wet Tropics Plan, accessed July 18, 2025,

Contextual Support Government

Reef 2050 Water Quality Improvement Plan

View Source

Context

Region Australia
Biome Tropical & Subtropical Rainforests
Land Use Aquaculture
Assessment Not Stated
Evidence Type DegradationThreshold

Lifecycle

Status Active
Version 1
Effective From 5 Jun 2026

Notes

This is a hard threshold for direct toxicity effects on aquatic life, but eutrophication risk occurs at much lower concentrations. AssessmentContext defaulted to 'Not Stated' because the source document did not state one.

Related Benchmarks

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