Water Electrical Conductivity (EC)

AUS-TSR-AQU-WEC General Moderate confidence

Benchmark Value

110 µS/cm
Range: 20 to 110 µS/cm
Optimal Range: 20 to 110
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 18 benchmarks together — the OptimalRange form drives the primary score, while 17 guard(s) constrain the result.

Contributing Benchmarks

OptimalRange Primary MinimumOnly Guard MaximumOnly Guard MaximumOnly Guard UpperThreshold Guard Point Guard LowerThreshold Guard OptimalRange Guard UpperThreshold Guard MaximumOnly Guard MinimumOnly Guard UpperThreshold Guard Point Guard OptimalRange Guard UpperThreshold Guard OptimalRange Guard LowerThreshold Guard UpperThreshold Guard

Evidence & Context

Therefore, a value of 110 µS/cm is proposed as the benchmark.

Metric Definition:

Water Electrical Conductivity (EC)

Benchmark Definition:

This benchmark represents the upper boundary of natural water electrical conductivity in minimally disturbed tropical rainforest streams, providing a target for sustainable aquaculture operations to protect environmental health.

Justification:

This value is conservative, scientifically defensible, and directly tied to empirical measurements from multiple high-health reference sites within the target biome. It represents the upper boundary of the typical natural range, providing a clear and measurable target for sustainable operations to meet.

Sources (3)

Preview of Compilation of riverine water quality data from the Great Barrier Reef catchment area, northeastern Australia - PubMed Central
Compilation of riverine water quality data from the Great Barrier Reef catchment area, northeastern Australia - PubMed Central GreyLiterature

Compilation of riverine water quality data from the Great Barrier Reef catchment area, northeastern Australia - PubMed Central, accessed July 21, 2025

View Source
Preview of Ecology of streams in a biogeographic isolate—the Queensland Wet Tropics, Australia | Freshwater Science: Vol 34, No 2, accessed July 22, 2025,
Ecology of streams in a biogeographic isolate—the Queensland Wet Tropics, Australia | Freshwater Science: Vol 34, No 2, accessed July 22, 2025, Journal

Australian and New Zealand Guidelines for Fresh and Marine Water Quality (ANZECC/ARMCANZ)

View Source
Preview of Terrestrial Ecosystem Research Network TERN Australia - Queensland science, accessed July 30, 2025,
Terrestrial Ecosystem Research Network TERN Australia - Queensland science, accessed July 30, 2025, Government

TERN Ecosystem Research Infrastructure | School of Biological Sciences

View Source

Supporting Sources (21)

Additional references from the underlying research that informed this benchmark.

Preview of (PDF) Effects of increasing salinity on freshwater ecosystems in Australia - ResearchGate, accessed August 11, 2025,
(PDF) Effects of increasing salinity on freshwater ecosystems in Australia - ResearchGate, accessed August 11, 2025,
Direct Evidence Journal

Effects of increasing salinity on freshwater ecosystems in Australia - ResearchGate

View Source
Preview of (PDF) Relationship between conductivity and analysed composition in a large set of natural surface-water samples, Queensland, Australia - ResearchGate, accessed July 21, 2025
(PDF) Relationship between conductivity and analysed composition in a large set of natural surface-water samples, Queensland, Australia - ResearchGate, accessed July 21, 2025
Contextual Support Journal

(PDF) Relationship between conductivity and analysed composition in a large set of natural surface-water samples, Queensland, Australia - ResearchGate, accessed July 21, 2025

View Source
Preview of (PDF) Water Quality Degradation of Coastal Waterways in the Wet Tropics, Australia, accessed August 2, 2025,
(PDF) Water Quality Degradation of Coastal Waterways in the Wet Tropics, Australia, accessed August 2, 2025,
Contextual Support

Requirements for graziers | Environment, land and water ..., accessed July 19, 2025,

View Source
Preview of A Bayesian approach to understanding the key factors influencing temporal variability in stream water quality – a case study in the Great Barrier Reef catchments - HESS
A Bayesian approach to understanding the key factors influencing temporal variability in stream water quality – a case study in the Great Barrier Reef catchments - HESS
Contextual Support Journal

(PDF) Water Quality Degradation of Coastal Waterways in the Wet Tropics, Australia, accessed July 21, 2025

View Source
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

Review and conceptual models of agricultural impacts and water quality in waterways of the Great Barrier Reef catchment area - CSIRO PUBLISHING | Marine and Freshwater Research, accessed July 21, 2025

View Source
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 All About Salinity - Environment and Heritage, accessed August 11, 2025
All About Salinity - Environment and Heritage, accessed August 11, 2025
Contextual Support

Impacts of salinity | Environment, land and water - Queensland Government, accessed July 28, 2025

View Source
Preview of An Aquaculture Industry for Queensland, accessed July 21, 2025
An Aquaculture Industry for Queensland, accessed July 21, 2025
Contextual Support Journal

NSW Marine Waters Sustainable Aquaculture Strategy, accessed July 21, 2025,

View Source
Preview of Australia Freshwater Ecology, Processes and Management | Request PDF - ResearchGate
Australia Freshwater Ecology, Processes and Management | Request PDF - ResearchGate
Contextual Support Journal

Salinity - Murray–Darling Basin Authority, accessed July 21, 2025

View Source
Preview of Best Pratice Environmental Management Guidelines for ... - VFA, accessed July 20, 2025,
Best Pratice Environmental Management Guidelines for ... - VFA, accessed July 20, 2025,
Contextual Support Government

NSW Land Based Sustainable Aquaculture Strategy, accessed July 21, 2025

View Source
Preview of Default guideline values - Water Quality Australia, accessed August 12, 2025
Default guideline values - Water Quality Australia, accessed August 12, 2025
Contextual Support Government

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

View Source
Preview of Default guideline values - Water Quality Australia, accessed July 21, 2025
Default guideline values - Water Quality Australia, accessed July 21, 2025
Contextual Support

Great Barrier Reef Water Quality: Current Issues - GBRMPA eLibrary, accessed July 21, 2025

View Source
Preview of Diatom–water quality thresholds in South Australian streams indicate a need for more stringent water quality guidelines - CSIRO PUBLISHING | Marine and Freshwater Research, accessed May 15, 2025,
Diatom–water quality thresholds in South Australian streams indicate a need for more stringent water quality guidelines - CSIRO PUBLISHING | Marine and Freshwater Research, accessed May 15, 2025,
Direct Evidence Journal

Diatom0water quality thresholds in South Australian streams indicate a need for more stringent water quality guidelines - CSIRO PUBLISHING | Marine and Freshwater Research

View Source
Preview of Land-use effects on water quality in an intensively managed catchment in the Australian humid tropics - CSIRO PUBLISHING | Marine and Freshwater Research, accessed July 21, 2025
Land-use effects on water quality in an intensively managed catchment in the Australian humid tropics - CSIRO PUBLISHING | Marine and Freshwater Research, accessed July 21, 2025
Contextual Support Journal

Ion regulation in fish gills: recent progress in the cellular and molecular mechanisms

View Source
Preview of Model operating conditions ERA 01 - Aquaculture, accessed July 21, 2025
Model operating conditions ERA 01 - Aquaculture, accessed July 21, 2025
Contextual Support Journal

Model operating conditions ERA 01 - Aquaculture, accessed July 21, 2025

View Source
Preview of Queensland Aquaculture Strategy 2024–2034
Queensland Aquaculture Strategy 2024–2034
Contextual Support Journal

Best Pratice Environmental Management Guidelines for Recirculating Aquaculture Systems, accessed July 21, 2025

View Source
Preview of Rainforest People Help Monitor Water Quality - Terrain NRM, accessed July 21, 2025
Rainforest People Help Monitor Water Quality - Terrain NRM, accessed July 21, 2025
Contextual Support GreyLiterature

Rainforest People Help Monitor Water Quality - Terrain NRM, accessed July 21, 2025

View Source
Preview of Search for environmental authorities | Queensland Government, accessed July 21, 2025
Search for environmental authorities | Queensland Government, accessed July 21, 2025
Regulatory Framework Government

Environmental authorities - Queensland Environment Department, accessed July 21, 2025

View Source
Preview of The influence of riparian vegetation on water quality in a mixed land use river basin - UQ eSpace, accessed July 18, 2025,
The influence of riparian vegetation on water quality in a mixed land use river basin - UQ eSpace, accessed July 18, 2025,
Contextual Support Journal

Queensland Aquaculture Strategy 2024–2034, accessed July 21, 2025

View Source
Preview of Tour TERN's rainforest monitoring SuperSite | TERN Australia, accessed July 22, 2025
Tour TERN's rainforest monitoring SuperSite | TERN Australia, accessed July 22, 2025
Contextual Support Government

Robson Creek Flux Data Release 2022_v2 - TERN Data Discovery Portal

View Source
Preview of Towards Environmental Sustainability in Marine Finfish Aquaculture - Frontiers, accessed July 21, 2025
Towards Environmental Sustainability in Marine Finfish Aquaculture - Frontiers, accessed July 21, 2025
Contextual Support Journal

Sustainability - MainStream Aquaculture, accessed July 21, 2025

View Source

Context

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

Lifecycle

  • Status Active
  • Version 1
  • Effective From 19 Mar 2026

Notes

The reference value is the upper limit of the typical range (20.0³110.9 ³S/cm) observed across 75 minimally disturbed forest streams in the Queensland Wet Tropics, representing an achievable state of high environmental health. Due to a lack of published monitoring data from verifiably 'best-practice' aquaculture sites, this reference ecosystem value is used as a proxy. Increasing EC is a key indicator of degradation; evidence suggests an upper detrimental threshold for ecosystem change (diatom communities) at ~280 ³S/cm, with more significant harm to broader biota above ~1500 ³S/cm. The high salinity tolerance of the cultured species (Barramundi) is not a valid indicator of ecosystem health; the benchmark must be set to protect the sensitive receiving environment. [Migration] Original wider evidence range: 20 – 110.9 (retained OptimalRange: 20 – 110)

Related Benchmarks

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

1500 µS/cm Moderate
Aquaculture · Pristine Reference
UpperThreshold Active v2
— µS/cm Moderate
Aquaculture · Pristine Reference
OptimalRange Active v1
280 µS/cm Moderate
Aquaculture · Pristine Reference
UpperThreshold Superseded v1