Water Nitrate

AUS-TMS-AQU-WNI General Moderate confidence

Benchmark Value

0.009 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

This value, rounded to 0.009 mg/L as NO3−​, is proposed as the scientifically defensible benchmark. It represents the ambient water quality condition that a best-practice farm must not compromise.

Metric Definition:

Water Nitrate concentration as NO3−​ in the receiving aquatic environment

Benchmark Definition:

This benchmark represents the water nitrate concentration in the receiving environment that protects aquatic ecosystem health in tropical monsoonal savanna aquaculture areas. It reflects the median ambient nitrate level that best-practice aquaculture should not exceed to avoid ecological harm.

Justification:

The benchmark is based on the median ambient nitrate concentration in a high-quality reference marine ecosystem, reflecting the water quality objective that a best-practice aquaculture facility must not compromise. The upper detrimental threshold is derived from the 80th percentile of the same reference data, representing the point beyond which ecological harm begins.

Sources (4)

Preview of Australian and New Zealand guidelines for fresh and marine water quality
Australian and New Zealand guidelines for fresh and marine water quality GreyLiterature

Australian and New Zealand guidelines for fresh and marine water quality, accessed July 24, 2025,

View Source
Preview of environment.nt.gov.au, accessed May 11, 2025,
environment.nt.gov.au, accessed May 11, 2025, Journal

Water Quality objectives for the region - Department of Lands, Planning and Environment

View Source
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

View Source
Preview of The impact of nitrate pollution in waterways on freshwater species, accessed August 8, 2025
The impact of nitrate pollution in waterways on freshwater species, accessed August 8, 2025 Journal

The impact of nitrate pollution in waterways on freshwater species, accessed July 24, 2025,

View Source

Supporting Sources (14)

Additional references from the underlying research that informed this benchmark.

Preview of A review of water quality studies relevant to northern Australia - CSIRO, accessed July 21, 2025,
A review of water quality studies relevant to northern Australia - CSIRO, accessed July 21, 2025,
Contextual Support Journal

Salinity and water quality

View Source
Preview of About the Water Quality Guidelines, accessed July 24, 2025
About the Water Quality Guidelines, accessed July 24, 2025
Contextual Support Journal

About the Water Quality Guidelines, accessed July 24, 2025,

View Source
Preview of Barramundi - NSW Department of Primary Industries, accessed July 24, 2025
Barramundi - NSW Department of Primary Industries, accessed July 24, 2025
Contextual Support GreyLiterature

Barramundi - NSW Department of Primary Industries, accessed July 24, 2025,

View Source
Preview of Barramundi - NSW Department of Primary Industries, accessed July 25, 2025,
Barramundi - NSW Department of Primary Industries, accessed July 25, 2025,
Contextual Support GreyLiterature

Real time monitoring of water quality and mechanisation of pond management to boost productivity and increase profit in Barramundi (Lates calcarifer), accessed July 24, 2025,

View Source
Preview of Brodie, J., Pearson, R., Lewis, S., Bainbridge, Z., Waterhouse, J. and Prange, J. (2009) Water Quality Research: Baseline Synthesis and Year 1 Summary - ResearchOnline@JCU - James Cook University, accessed July 20, 2025,
Brodie, J., Pearson, R., Lewis, S., Bainbridge, Z., Waterhouse, J. and Prange, J. (2009) Water Quality Research: Baseline Synthesis and Year 1 Summary - ResearchOnline@JCU - James Cook University, accessed July 20, 2025,
Contextual Support Journal

Public Environmental Report Blackmore River (East ... - NT EPA, accessed July 24, 2025,

View Source
Preview of Brodie, J., Pearson, R., Lewis, S., Bainbridge, Z., Waterhouse, J. and Prange, J. (2009) Water Quality Research: Baseline Synthesis and Year 1 Summary - ResearchOnline@JCU - James Cook University, accessed July 24, 2025
Brodie, J., Pearson, R., Lewis, S., Bainbridge, Z., Waterhouse, J. and Prange, J. (2009) Water Quality Research: Baseline Synthesis and Year 1 Summary - ResearchOnline@JCU - James Cook University, accessed July 24, 2025
Contextual Support Journal

Brodie, J., Pearson, R., Lewis, S., Bainbridge, Z., Waterhouse, J. and Prange, J. (2009) Water Quality Research: Baseline Synthesis and Year 1 Summary - ResearchOnline@JCU - James Cook University, accessed July 24, 2025,

View Source
Preview of Characterising the relationship between water quality and water quantity, accessed August 5, 2025
Characterising the relationship between water quality and water quantity, accessed August 5, 2025
Contextual Support Journal

Turbidity | Australia state of the environment 2021

View Source
Preview of Industry | Australia state of the environment 2021, accessed August 2, 2025,
Industry | Australia state of the environment 2021, accessed August 2, 2025,
Contextual Support

R&D Priorities – Australia's estuaries, embayments and nearshore marine environments, accessed July 24, 2025,

View Source
Preview of Nitrogen budget and effluent nitrogen components at an intensive shrimp farm | Request PDF - ResearchGate, accessed August 1, 2025
Nitrogen budget and effluent nitrogen components at an intensive shrimp farm | Request PDF - ResearchGate, accessed August 1, 2025
Contextual Support Journal

Nitrogen a limiting factor in aquaculture production - Responsible Seafood Advocate, accessed July 24, 2025,

View Source
Preview of Revision to the ANZG 2018 Water Quality Guidelines | iEnvi, accessed July 26, 2025,
Revision to the ANZG 2018 Water Quality Guidelines | iEnvi, accessed July 26, 2025,
Contextual Support Government

Revision to the ANZG 2018 Water Quality Guidelines | iEnvi, accessed July 24, 2025,

View Source
Preview of The sustainability behind farmed Australian barramundi, accessed July 24, 2025
The sustainability behind farmed Australian barramundi, accessed July 24, 2025
Contextual Support GreyLiterature

JCU project to help safeguard prawn industry - JCU Australia

View Source
Preview of Wastewater remediation options for prawn farms, accessed August 1, 2025
Wastewater remediation options for prawn farms, accessed August 1, 2025
Contextual Support Journal

Enhancing Nitrate Removal from Freshwater Pond by Regulating Carbon/Nitrogen Ratio - Frontiers, accessed July 24, 2025,

View Source
Preview of Wastewater remediation options for prawn farms, accessed July 24, 2025
Wastewater remediation options for prawn farms, accessed July 24, 2025
Contextual Support

Wastewater remediation options for prawn farms, accessed July 24, 2025,

View Source
Preview of Water quality guidelines - Queensland Environment Department, accessed August 1, 2025,
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)

View Source

Context

  • Region Australia
  • Biome Tropical Monsoonal Savannas
  • Land Use Aquaculture
  • Assessment Not Stated
  • Evidence Type ReferenceCondition

Lifecycle

  • Status Active
  • Version 1
  • Effective From 5 Jun 2026

Notes

An effluent-based benchmark is scientifically unsound as nitrate is a minor (<3%) and potentially misleading component of the total nitrogen discharged from pond systems, which is dominated by organic and ammonia forms. The concepts of a lower critical threshold or an optimal range are not ecologically relevant for this indicator in the naturally low-nutrient receiving waters, where maintaining the lowest possible anthropogenic input is the objective. The upper detrimental threshold of 0.16 mg/L represents the concentration beyond which the ecosystem state deviates significantly from its natural, high-health condition, increasing the risk of eutrophication. AssessmentContext defaulted to 'Not Stated' because the source document did not state one.