The importance of water as a resource and the appropriate management thereof is becoming even more important in South Africa. Recent events where several municipalities in Cape Town have been classed as disaster areas due to the severe drought, and constant raw sewage spills recorded in the Vaal River and other river systems are indicators of miss-management.

Environmental Assurance’s aquatic ecologists employ several indices with our bio-monitoring projects to ensure that early warning systems are in place to identify impacts. One major index used is known as the Rapid Habitat Assessment Method (RHAM) which forms part of the River Ecostatus Monitoring Programme (REMP).

This method is based on a simplified approach to determine the velocity, depth, substrate and cover needed for fish communities and the velocity, substrate and cover needed for invertebrate communities. A river reach is divided into several cross sections depending on the scope of the project where the following is assessed:

• Basic In situ physico-chemical measurements;
• Cross sectional measurements;
• IHI (Which assesses the instream and riparian ecological integrity);
• Fish and Invertebrate habitat requirements are assessed using:
  • Fish Response Assessment Index (FRAI);
  • South African Scoring System V5 (SASS5); and
  • Invertebrate Habitat Assessment (IHAS).

The indices are combined to provide an Ecostatus for the reach, if this Ecostatus does not fall within the approved category set out by the Department of Water and Sanitation, achievable ecological targets are set in order to achieve both economic growth and rehabilitation of the environment.

In situ Water Quality using an Aquaprobe AP-800

South African Scoring System 5 as prescribed by Dickens and Graham (2002)

Invertebrate Habitat Assessment

FRAI – Electrofishing and Fish community studies

For a free proposal on any relevant project please contact: info@envass.co.za