Water Nitrate — Benchmark Detail - Nature Index

Benchmark Value

0.007 mg/L

Range: — to 0.007 mg/L

Optimal Range: — to 0.007

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 6 benchmarks together — the OptimalRange form drives the primary score, while 5 guard(s) constrain the result.

Contributing Benchmarks

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

Evidence & Context

Based on an analysis of the data from this high-health reference site, the recommended benchmark for Water Nitrate is 0.007 mg/L (as NO3).

Metric Definition:

Water Nitrate concentration as NO3 in water representing the best available natural condition for Conservation and Protected Natural Areas within Australia's Tropical and Subtropical Maritime Islands biome.

Benchmark Definition:

Water Nitrate concentration benchmark representing the 80th percentile of measured nitrate/nitrite (NOx) concentrations from a minimally disturbed conservation area.

Justification:

This benchmark is derived from the 80th percentile of measured nitrate/nitrite concentrations at the Annan-Endeavour focus region, the only region meeting GBRMPA water quality guidelines for NOx in 2022-23, representing a high ecological health state.

Sources (2)

Preview of (PDF) Marine Monitoring Program: Annual Report for Inshore Water Quality Monitoring 2022-23 - ResearchGate, accessed July 20, 2025,

(PDF) Marine Monitoring Program: Annual Report for Inshore Water Quality Monitoring 2022-23 - ResearchGate, accessed July 20, 2025, GreyLiterature

Gruber, R., et al. (2024). Marine Monitoring Program: Annual Report for Inshore Water Quality Monitoring 2022-23. Great Barrier Reef Marine Park Authority. 18

Preview of Great Barrier Reef Marine Park Authority (GBRMPA). (2024). Marine Monitoring Program 2022-23 Summary Results Booklet.

Great Barrier Reef Marine Park Authority (GBRMPA). (2024). Marine Monitoring Program 2022-23 Summary Results Booklet.

Great Barrier Reef Marine Park Authority (GBRMPA). (2024). Marine Monitoring Program 2022-23 Summary Results Booklet. 21

Supporting Sources (23)

Additional references from the underlying research that informed this benchmark.

Preview of Australian and New Zealand Governments (ANZG). (2018). Australian and New Zealand Guidelines for Fresh and Marine Water Quality. Canberra ACT, Australia. 32

Australian and New Zealand Governments (ANZG). (2018). Australian and New Zealand Guidelines for Fresh and Marine Water Quality. Canberra ACT, Australia. 32

Regulatory Framework Journal

Environmental Values, Water Quality Objectives and Targets for the Black Ross Water Quality Improvement Plan Appendices December - Creek to Coral, accessed July 31, 2025,

Preview of Department of Climate Change, Energy, the Environment and Water (DCCEEW). (n.d.). Lord Howe Island Marine Park (Commonwealth Waters) Management Plan. 38

Department of Climate Change, Energy, the Environment and Water (DCCEEW). (n.d.). Lord Howe Island Marine Park (Commonwealth Waters) Management Plan. 38

Contextual Support Journal

Department of Climate Change, Energy, the Environment and Water (DCCEEW). (n.d.). Lord Howe Island Marine Park (Commonwealth Waters) Management Plan. 38

Preview of Department of Infrastructure and Regional Development. (2017). Christmas Island Groundwater Project Factsheet. 13

Department of Infrastructure and Regional Development. (2017). Christmas Island Groundwater Project Factsheet. 13

Contextual Support Journal

Department of Infrastructure and Regional Development. (2017). Christmas Island Groundwater Project Factsheet. 13

Preview of Development of basin-specific ecologically relevant water quality targets for the Great Barrier Reef, accessed August 3, 2025,

Development of basin-specific ecologically relevant water quality targets for the Great Barrier Reef, accessed August 3, 2025,

Contextual Support Journal

Lewis, S. E., et al. (2017). Development of basin-specific ecologically relevant water quality targets for the Great Barrier Reef. Reef Water Quality Protection Plan. 41

Preview of Diving deeper into nutrient pathways to help protect Lord Howe Island's marine haven, accessed August 4, 2025,

Diving deeper into nutrient pathways to help protect Lord Howe Island's marine haven, accessed August 4, 2025,

Contextual Support GreyLiterature

Australian Institute of Marine Science (AIMS). (2024, September 4). Diving deeper into nutrient pathways to help protect Lord Howe Island's marine haven. 9

Preview of Eutrophication and Water quality - Global Coral Reef Alliance, accessed August 1, 2025

Eutrophication and Water quality - Global Coral Reef Alliance, accessed August 1, 2025

Contextual Support GreyLiterature

Eutrophication and Water quality - Global Coral Reef Alliance, accessed August 1, 2025,

Preview of Frequently asked questions | Report card 2021 and 2022 | Reef 2050 Water Quality Improvement Plan, accessed July 27, 2025,

Frequently asked questions | Report card 2021 and 2022 | Reef 2050 Water Quality Improvement Plan, accessed July 27, 2025,

Contextual Support Government

Queensland Government. (2024). Reef Water Quality Report Card 2021 and 2022: Frequently asked questions. 45

Preview of Gattuso, J-P., et al. (2015). Contrasting futures for ocean and society from different anthropogenic CO2 emissions scenarios. Science, 349(6243). 27

Gattuso, J-P., et al. (2015). Contrasting futures for ocean and society from different anthropogenic CO2 emissions scenarios. Science, 349(6243). 27

Direct Evidence

Gattuso, J-P., et al. (2015). Contrasting futures for ocean and society from different anthropogenic CO2 emissions scenarios. Science, 349(6243). 27

Preview of Geoscience Australia. (1999). Christmas Island Water Resources GIS Data Layers. 12

Geoscience Australia. (1999). Christmas Island Water Resources GIS Data Layers. 12

Contextual Support Government

Geoscience Australia. (1999). Christmas Island Water Resources GIS Data Layers. 12

Preview of Goreau, T. J. (n.d.). Coral Reefs, Sewage, and Water Quality Standards. Global Coral Reef Alliance. 23

Goreau, T. J. (n.d.). Coral Reefs, Sewage, and Water Quality Standards. Global Coral Reef Alliance. 23

Contextual Support GreyLiterature

Goreau, T. J. (n.d.). Coral Reefs, Sewage, and Water Quality Standards. Global Coral Reef Alliance. 23

Preview of Houk, P., et al. (2022). Nutrient thresholds to protect water quality, coral reefs, and nearshore fisheries. Marine Pollution Bulletin, 184, 114131.

Houk, P., et al. (2022). Nutrient thresholds to protect water quality, coral reefs, and nearshore fisheries. Marine Pollution Bulletin, 184, 114131.

Direct Evidence

Houk, P., et al. (2022). Nutrient thresholds to protect water quality, coral reefs, and nearshore fisheries. Marine Pollution Bulletin, 184, 114131. 26

Preview of Humphries, M. S., et al. (2017). Searching for water on Christmas Island. ResearchGate. 10

Humphries, M. S., et al. (2017). Searching for water on Christmas Island. ResearchGate. 10

Contextual Support

Humphries, M. S., et al. (2017). Searching for water on Christmas Island. ResearchGate. 10

Preview of Latest Great Barrier Reef water quality Scientific Consensus Statement released - CSIRO, accessed August 1, 2025

Latest Great Barrier Reef water quality Scientific Consensus Statement released - CSIRO, accessed August 1, 2025

Contextual Support GreyLiterature

Latest Great Barrier Reef water quality Scientific Consensus Statement released - CSIRO, accessed August 1, 2025,

Preview of LORD HOWE ISLAND A Summary of Current and Projected Scientific and Environmental Activities - Australian Museum, accessed July 30, 2025

LORD HOWE ISLAND A Summary of Current and Projected Scientific and Environmental Activities - Australian Museum, accessed July 30, 2025

Contextual Support Journal

Baseline high-resolution maps of organic carbon content in Australian soils - PMC

Preview of Lord Howe Island Marine Park News Water Quality Research Collaboration, accessed August 3, 2025,

Lord Howe Island Marine Park News Water Quality Research Collaboration, accessed August 3, 2025,

Contextual Support Journal

Lord Howe Island Marine Park. (2024, June). Lord Howe Island Marine Park News. 8

Preview of Nitrate in freshwater and marine water - Water Quality Australia, accessed August 2, 2025,

Nitrate in freshwater and marine water - Water Quality Australia, accessed August 2, 2025,

Contextual Support

Nitrate - Water Quality Australia, accessed August 1, 2025

Preview of Parks Australia. (2025). Director of National Parks Report on comments for the Christmas Island and Cocos (Keeling) Islands draft management plans. 44

Parks Australia. (2025). Director of National Parks Report on comments for the Christmas Island and Cocos (Keeling) Islands draft management plans. 44

Regulatory Framework Government

Department of Climate Change, Energy, the Environment and Water (DCCEEW). (n.d.). Lord Howe Island Biodiversity Management Plan. 40

Preview of Parks Australia. (n.d.). Christmas Island on the frontline of battle against ocean plastic pollution. Australian Marine Parks. 42

Parks Australia. (n.d.). Christmas Island on the frontline of battle against ocean plastic pollution. Australian Marine Parks. 42

Contextual Support Government

Parks Australia. (n.d.). Christmas Island on the frontline of battle against ocean plastic pollution. Australian Marine Parks. 42

Preview of Tangaroa Blue Foundation. (2024). Christmas Island Marine Debris Report. 11

Tangaroa Blue Foundation. (2024). Christmas Island Marine Debris Report. 11

Contextual Support Journal

Tangaroa Blue Foundation. (2024). Christmas Island Marine Debris Report. 11

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

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

Contextual Support Journal

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

Preview of Water Quality Guidelines for the Great Barrier Reef Marine Park., accessed August 3, 2025,

Water Quality Guidelines for the Great Barrier Reef Marine Park., accessed August 3, 2025,

Regulatory Framework Journal

Great Barrier Reef Marine Park Authority (GBRMPA). (2010). Water Quality Guidelines for the Great Barrier Reef Marine Park. Rev. ed. 35

Preview of Webb, K. L., & Wiebe, W. J. (1978). The kinetics and possible significance of nitrate uptake by several algal-invertebrate symbioses. Marine Biology, 47, 21-27. 5

Webb, K. L., & Wiebe, W. J. (1978). The kinetics and possible significance of nitrate uptake by several algal-invertebrate symbioses. Marine Biology, 47, 21-27. 5

Contextual Support

Webb, K. L., & Wiebe, W. J. (1978). The kinetics and possible significance of nitrate uptake by several algal-invertebrate symbioses. Marine Biology, 47, 21-27. 5

Preview of Wiedenmann, J., et al. (2013). Nutrient enrichment can increase the susceptibility of reef corals to bleaching. Nature Climate Change, 3, 160-164. 24

Wiedenmann, J., et al. (2013). Nutrient enrichment can increase the susceptibility of reef corals to bleaching. Nature Climate Change, 3, 160-164. 24

Contextual Support

Wiedenmann, J., et al. (2013). Nutrient enrichment can increase the susceptibility of reef corals to bleaching. Nature Climate Change, 3, 160-164. 24

Context

Region Australia
Biome Tropical & Subtropical Maritime Islands
Land Use Conservation / Protected Natural Areas
Assessment Conservation Target
Evidence Type ReferenceCondition

Lifecycle

Status Active
Version 1
Effective From 17 Mar 2026

Notes

The benchmark should be considered an upper limit for a high-health state in naturally oligotrophic ecosystems. The concept of a lower critical threshold is not ecologically relevant as these systems are naturally nutrient-limited. Any significant increase above this value indicates potential ecosystem stress and departure from natural condition.

Related Benchmarks

Other benchmarks in the AUS-TMI-CON-WNI family.