Development of new assessment approach: a macroinvertebrates-based biotic scoring system to assess the health of riverine ecosystems in the Sahel area in Burkina Faso (West Africa)

Abstract

To address ongoing threats from human pressures and climate changes, water managers and users require a visual tool that provides accurate information about the health of waterbodies for decision making. However, there is a lack of less sophisticated methods, such as biotic scoring, to assess the health of rivers in West Africa. To bridge this gap, we have developed a macroinvertebrate-based scoring system for monitoring the health of rivers in the Sahelian regions. We adopted a multi-habitat sampling approach to collect macroinvertebrates using hand nets, and these specimens were identified mostly to family taxonomic level using keys. We recorded more than 75 taxa of macroinvertebrates, each assigned relative sensitivity scores to human disturbances ranging from 1 (very tolerant) to 10 (highly sensitive). The Burkina Biotic Score System (BBIOSS) and the Average Score Per Taxa (ASPT) demonstrated a strong and significant correlation with environmental variables, including anthropogenic pressures types (r = 0.6; p < 0.01) making it a robust tool for monitoring rivers. Here, our findings revealed that all taxa scored are expected to be those reported in Western African freshwater. This study has produced an effective tool that can be used or adapted to monitor other riverine ecosystems in West Africa, potentially contributing to the preservation of water and biological resources.

Keywords:

• biotic indices
• bioassessment
• ecological integrity
• rivers
• West Africa