Water Turbidity

AUS-TMI-AQU-WTU General Moderate confidence

Benchmark Value

4.5 NTU

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 15 benchmarks together — the OptimalRange form drives the primary score, while 14 guard(s) constrain the result.

Contributing Benchmarks

OptimalRange Primary MaximumOnly Guard OptimalRange Guard Point Guard MaximumOnly Guard MaximumOnly Guard MaximumOnly Guard MaximumOnly Guard OptimalRange Guard MaximumOnly Guard Point Guard LowerThreshold Guard OptimalRange Guard MaximumOnly Guard MaximumOnly Guard

Evidence & Context

Indicator Name: Water Turbidity Reference Value: 4.5 Unit: NTU Source Title: Sensory compensation and the detection of chemical alarm cues by a coral reef fish Confidence Level: Moderate

Metric Definition:

Water Turbidity is a measure of the degree to which water loses its transparency due to the presence of suspended particulates, quantified in Nephelometric Turbidity Units (NTU).

Benchmark Definition:

This benchmark represents the turbidity level of 4.5 NTU, indicating water clarity associated with an unaffected reef condition in the Tropical & Subtropical Maritime Islands biome under aquaculture land use. It reflects a state of high ecological integrity important for aquatic ecosystem health.

Justification:

The 4.5 NTU value is a direct field measurement from the correct biome and is explicitly associated with a state of high ecological integrity. Its alignment with the 4.1 NTU T90 value from the broader GBR survey adds strong corroborative support.

Sources (2)

Preview of Sensory compensation and the detection of chemical alarm cues by a coral reef fish

Sensory compensation and the detection of chemical alarm cues by a coral reef fish Journal

Sensory compensation and the detection of chemical alarm cues by a coral reef fish

Preview of Turbidity and light attenuation in coastal waters of the Great Barrier Reef - ResearchOnline@JCU, accessed August 2, 2025,

Turbidity and light attenuation in coastal waters of the Great Barrier Reef - ResearchOnline@JCU, accessed August 2, 2025, Journal

Turbidity and light attenuation in coastal waters of the Great Barrier Reef - ResearchOnline@JCU

Supporting Sources (20)

Additional references from the underlying research that informed this benchmark.

Preview of Acropora tenuis energy acquisition along a natural turbidity gradient - Frontiers, accessed August 1, 2025,

Acropora tenuis energy acquisition along a natural turbidity gradient - Frontiers, accessed August 1, 2025,

Contextual Support Journal

Acropora tenuis energy acquisition along a natural turbidity gradient - Frontiers, accessed August 1, 2025,

Preview of Aquaculture species | NT.GOV.AU, accessed August 1, 2025,

Aquaculture species | NT.GOV.AU, accessed August 1, 2025,

Contextual Support Government

Aquaculture species | NT.GOV.AU, accessed August 1, 2025,

Preview of Australis First in World to Achieve Tropical Marine Finfish ASC Certification, accessed August 1, 2025,

Australis First in World to Achieve Tropical Marine Finfish ASC Certification, accessed August 1, 2025,

Contextual Support GreyLiterature

Turbidity Characteristics of The Waters on The ... - Omni-Akuatika

Preview of Black tiger prawn aquaculture | Business Queensland, accessed August 1, 2025

Black tiger prawn aquaculture | Business Queensland, accessed August 1, 2025

Contextual Support Government

Freshwater aquaculture | Business Queensland, accessed August 1, 2025

Preview of Cocos (Keeling) Islands Marine Park, accessed August 1, 2025,

Cocos (Keeling) Islands Marine Park, accessed August 1, 2025,

Contextual Support Government

Cocos (Keeling) Islands Marine Park, accessed August 1, 2025,

Preview of Developing a reef water quality management plan — case study, accessed August 3, 2025,

Developing a reef water quality management plan — case study, accessed August 3, 2025,

Contextual Support Government

Altered water flows and quality | Wet Tropics Management Authority, accessed July 27, 2025

Preview of Environmental Code of Practice for Australian Prawn Farmers - NTEPA, accessed August 1, 2025,

Environmental Code of Practice for Australian Prawn Farmers - NTEPA, accessed August 1, 2025,

Regulatory Framework Journal

Environmental Code of Practice for Australian Prawn Farmers - NTEPA, accessed August 1, 2025,

Preview of ESR/2015/1683 Wastewater licencing from existing marine prawn farms, accessed August 1, 2025,

ESR/2015/1683 Wastewater licencing from existing marine prawn farms, accessed August 1, 2025,

Regulatory Framework Journal

ESR/2015/1683 Wastewater licencing from existing marine prawn farms, accessed August 1, 2025,

Preview of gbr-dredge-material-management-appendixb.docx - DCCEEW, accessed August 1, 2025,

gbr-dredge-material-management-appendixb.docx - DCCEEW, accessed August 1, 2025,

Contextual Support Journal

Spatial Patterns in Water Quality Changes during Dredging in Tropical Environments - PMC, accessed August 1, 2025,

Preview of Important Water Quality Parameters in Aquaculture: An Overview - ResearchGate, accessed August 1, 2025,

Important Water Quality Parameters in Aquaculture: An Overview - ResearchGate, accessed August 1, 2025,

Contextual Support GreyLiterature

Important Water Quality Parameters in Aquaculture: An Overview - ResearchGate, accessed August 1, 2025,

Preview of Interactive effects of sedimentary turbidity and elevated water temperature on the Pugnose Shiner (Miniellus anogenus), a threatened freshwater fish | Conservation Physiology | Oxford Academic

Interactive effects of sedimentary turbidity and elevated water temperature on the Pugnose Shiner (Miniellus anogenus), a threatened freshwater fish | Conservation Physiology | Oxford Academic

Contextual Support Journal

To fear or to feed: the effects of turbidity on perception of risk by a ..., accessed August 1, 2025,

Preview of National Guidelines for Water Quality - Department of Natural Resources and Environment Tasmania, accessed August 1, 2025,

National Guidelines for Water Quality - Department of Natural Resources and Environment Tasmania, accessed August 1, 2025,

Regulatory Framework

Using the ANZECC Guidelines and Water Quality Objectives in NSW

Preview of Queensland Aquaculture Policy Statement - The Queensland ..., accessed August 1, 2025,

Queensland Aquaculture Policy Statement - The Queensland ..., accessed August 1, 2025,

Regulatory Framework Journal

Queensland Aquaculture Policy Statement - The Queensland ..., accessed August 1, 2025,

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

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

Regulatory Framework Government

land and water | Queensland Government

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

Contextual Support Journal

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

Preview of Turbidity Characteristics of The Waters on The ... - Omni-Akuatika

Turbidity Characteristics of The Waters on The ... - Omni-Akuatika

Contextual Support Journal

Turbidity Characteristics of The Waters on The ... - Omni-Akuatika, accessed August 1, 2025,

Preview of Using the ANZECC Guidelines and Water Quality Objectives in NSW, accessed August 11, 2025,

Using the ANZECC Guidelines and Water Quality Objectives in NSW, accessed August 11, 2025,

Regulatory Framework Journal

Reference-site data - Water Quality Australia

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,

Preview of Water Quality - GBRMPA eLibrary, accessed August 1, 2025,

Water Quality - GBRMPA eLibrary, accessed August 1, 2025,

Contextual Support

Catchments and corals: terrestrial runoff to the Great Barrier Reef - The Australian Institute of Marine Science, accessed July 28, 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

Determining Tipping Points and Responses of Macroinvertebrate Traits to Abiotic Factors in Support of River Management - PubMed Central

Context

Region Australia
Biome Tropical & Subtropical Maritime Islands
Land Use Aquaculture
Assessment Not Stated
Evidence Type ReferenceCondition

Lifecycle

Status Active
Version 1
Effective From 1 Jun 2026

Notes

No upper detrimental threshold — higher values are always worse for water clarity and ecosystem health. AssessmentContext defaulted to 'Not Stated' because the source document did not state one.

Related Benchmarks

Other benchmarks in the AUS-TMI-AQU-WTU family.