<![CDATA[River ecosystems play an important role in supporting human life and aquatic biodiversity, but their quality can decline due to anthropogenic activities. This study aimed to analyze the water quality of the Gunung Pengsong River, West Lombok, using aquatic macrofauna as bioindicators. The research applied a descriptive-exploratory method by collecting macrofauna samples through free sampling along a 1 km river section near residential and agricultural areas. Water quality analysis was conducted using the BMWP (Biological Monitoring Working The community around the Gunung Pengsong tourism area has limited knowledge of using aquatic organisms as biological indicators to monitor river water quality. Most residents assess water quality only through physical observations such as color, odor, and turbidity. Therefore, a community service program was conducted to improve public understanding of bioindicators and their application in environmental monitoring. The activity involved 30 participants, including residents and Biology Education students. The program was implemented through educational sessions, field demonstrations, direct sampling of aquatic macrofauna, organism identification practices, and group discussions. Participants were actively involved throughout all stages of the activity. Evaluation through observation, discussions, and interviews indicated an improvement in participants’ understanding of the relationship between aquatic organisms and river ecosystem conditions. After the training, participants were able to recognize several groups of macrofauna and understand their role as indicators of water quality. The use of macrofauna-based bioindicators was considered easy to understand and applicable for community-based environmental monitoring. This activity successfully enhanced environmental awareness and strengthened participants’ knowledge and skills in monitoring river water quality using biological indicators.]]>
