Water Nitrate — Benchmark Detail

Benchmark Value

1 mg/L

Range: 0 to 1 mg/L

Optimal Range: 0 to 1

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

The benchmark of <1 mg/L TN represents the practical lower limit of this range achievable by leading operators.

Metric Definition:

Average Total Nitrogen (TN) concentration in discharge water from best-practice aquaculture farms

Benchmark Definition:

This benchmark represents the maximum total nitrogen concentration in discharge water from aquaculture farms in tropical and subtropical rainforests, reflecting the best achievable environmental performance using current best-practice management.

Justification:

This value signifies the highest achievable environmental performance using current best-practice management and treatment technologies.

Sources (1)

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

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

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

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Supporting Sources (9)

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

Declining water quality - Reef Authority

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

Contextual Support Government

Denitrification in intertidal sediments of a tropical estuary subject to increasing development pressures - Northern Territory Government

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Industry | Australia state of the environment 2021

Contextual Support Journal

Industry | Australia state of the environment 2021

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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.

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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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Toxicant default guideline values for aquatic ecosystem protection ...

Contextual Support

Default guideline values - Water Quality Australia

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

Contextual Support Government

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

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

Contextual Support Journal

Salinity | Murray–Darling Basin Authority, accessed August 8, 2025,

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

Contextual Support Government

Queensland Aquaculture Strategy 2024–2034

View Source

Context

Region Australia
Biome Tropical & Subtropical Rainforests
Land Use Aquaculture
Assessment Pristine Reference
Evidence Type TargetCondition

Lifecycle

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

Notes

The optimal range for discharge is as close to zero as possible to align with the naturally low-nutrient status of receiving waters. There is no 'critically low' level of nitrogen discharge that is beneficial or required. The ecological goal is minimization, with zero discharge being the ideal. No upper detrimental threshold — higher values are always worse.

Related Benchmarks

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