Services · Specialist

Aquatic Invertebrate Surveys

Aquatic invertebrate communities are powerful indicators of water quality and habitat health. We deliver macroinvertebrate surveys producing RIVPACS-compatible results — used for Water Framework Directive compliance, EIA and development impact assessment.

MethodKick sampling & sweep netting
ScoringBMWP / WHPT / RIVPACS
SeasonSpring & Autumn
ApplicationWater quality assessment

Overview

Aquatic invertebrate surveys assess the macroinvertebrate community of rivers, streams, ponds, lakes and ditches. Because different invertebrate families have different tolerances to pollution, the community composition is a direct and reliable indicator of water quality — often more informative than spot chemical sampling.

Standard methodology follows Environment Agency protocols: three-minute kick samples and one-minute sweep net samples collected from the range of available microhabitats. Specimens are identified in the laboratory to family level (or species level for specific target groups) and scored using the Biological Monitoring Working Party (BMWP) system, the Whalley Hawkes Paisley Trigg (WHPT) index, or the RIVPACS predictive system depending on the assessment purpose.

Results feed into Water Framework Directive classification, Environmental Impact Assessment, baseline characterisation for development projects and post-construction monitoring programmes. We also survey for specific protected or notable aquatic invertebrate species — white-clawed crayfish, for example — where habitat suggests they may be present.

When you need this

  • Your development will discharge into or abstract from a watercourse and needs Water Framework Directive assessment
  • An Environmental Impact Assessment requires aquatic ecology baseline data
  • The Environment Agency or LPA requires water quality or aquatic habitat assessment
  • Your project involves river restoration, culverting, channel modification or in-stream works
  • Baseline monitoring is required before and after construction near watercourses

Our approach

  1. 01
    Site reconnaissance

    We assess the waterbody to identify sampling locations, microhabitat types and access points. Sampling is designed to be representative of the full habitat range present.

  2. 02
    Field sampling

    Three-minute kick samples and one-minute sweep net samples are collected following Environment Agency standard methodology. Samples are preserved for laboratory analysis.

  3. 03
    Laboratory identification

    Specimens are sorted and identified to family level (or species level where required). Abundances are recorded and community indices (BMWP, WHPT, LIFE, PSI) are calculated.

  4. 04
    Reporting

    Results are presented with community indices, interpretation of water quality and habitat condition, comparison with expected community composition and clear recommendations for mitigation or monitoring.

Frequently asked questions

01What does an aquatic invertebrate survey tell you?+
The invertebrate community reflects long-term water quality and habitat condition — it integrates everything the organisms have been exposed to, rather than providing a snapshot like a chemical sample. High BMWP scores indicate clean, well-oxygenated water with diverse habitats. Low scores suggest pollution, sedimentation or habitat degradation.
02Do I need spring and autumn samples?+
For RIVPACS-compatible results and formal WFD classification, paired spring and autumn samples are standard practice. For screening-level assessments or baseline characterisation, a single-season sample can be sufficient depending on the purpose of the survey.
03Can white-clawed crayfish be detected during an invertebrate survey?+
Kick sampling may detect white-clawed crayfish incidentally, but if this protected species is a specific concern, targeted crayfish survey methods (manual searching, trapping under licence) are more reliable and should be carried out separately.
Get in touch

Have a site that needs surveying?

Tell us about the project. We'll come back with a clear scope, timing and a fixed quote.

Request a quote→