Overview
ISO 8689-2:2000 provides guidance on the presentation of biological quality data for rivers based on surveys of benthic macroinvertebrates. It is the second part of ISO 8689 and is intended to be used with standard sampling and classification methods (notably ISO 8689-1). The standard focuses on how to display and communicate survey results-primarily via colour‑coded maps that show biological quality across river reaches.
Key Topics and Requirements
- Scope: Presentation of biological quality data from benthic macroinvertebrate surveys of running waters, using standard sampling and classification procedures.
- Reach concept: Watercourses should be divided into reaches-lengths defined by distinguishing physical, chemical or hydrological characteristics-so that biological quality is internally consistent.
- Representative sampling site: Within each reach, select a site that reflects the reach’s biological quality; use that site’s results for presentation.
- Sampling and identification: Follow referenced ISO sampling guidance (see Related Standards). Sorting and identification must suit the indices used in classification.
- Classification and mapping:
- Produce a colour‑coded map showing reaches coloured by class (representative site).
- Required map elements: watercourse names, upstream/downstream reach limits, representative sampling site locations, and flow direction.
- Prescribed colour scheme (Table 1): Blue = High, Green = Good, Yellow = Moderate, Orange = Poor, Red = Bad.
- Black may be used (outside the classification) to indicate absence of indicator organisms (e.g., due to toxicity).
- Unsurveyed reaches should be shown as a fine black line to indicate data gaps.
Applications and Users
Practical uses of ISO 8689-2 include:
- Pollution assessment and biological monitoring of rivers
- Classification of water quality for regulatory reporting
- Baseline mapping for habitat restoration and conservation planning
- Tracking temporal or spatial changes in biological quality
Primary users:
- Environmental agencies and regulators
- Aquatic ecologists and biomonitoring specialists
- Environmental consultants and contractors conducting surveys
- Researchers, NGOs and water resource managers
Related Standards
Normative references integral to implementing ISO 8689-2:
- ISO 8689-1 - Guidance on interpretation of biological quality data
- ISO 5667-3 - Sampling: preservation and handling
- ISO 7828 - Handnet sampling guidance
- ISO 8265 - Quantitative samplers for stony substrata
- ISO 9391 - Sampling in deep waters and colonization samplers
Using ISO 8689-2 ensures consistent, transparent presentation of biological quality data from benthic macroinvertebrate surveys, supporting clear communication, mapping and decision‑making in river water quality management.