WATER HYACINTH (Pontederia crassipes) BLOOM IN BENGAWAN SOLO RIVER, INDONESIA: AN AQUATIC PHYSICOCHEMICAL AND BIOLOGY PERSPECTIVE

This research aims to investigate the blooming phenomenon of alien invasive plants in the Bengawan Solo River using an aquatic physicochemical and biology analysis approach. This research method involves collecting water samples from locations impacted by the alien invasive plants. Sampling point 1 at 7°08'05.3"S 111°43'13.9"E; Sampling point 2 at 7°06'59.6"S 111°43'33.2"E; Sampling point 3 at 7°06'39.3"S 111°44'05.4"E; and Sampling point 4 at 7°06'58.5"S 111°44'54.2"E is near to rice field area. Physical parameters measured included turbidity (NTU) and water temperature (°C), while chemical parameters included pH, dissolved oxygen level (DO in ppm), oxygen saturation (%), nitrate (NO3 in ppm), phosphate (PO4 in ppm), total dissolved solids (TDS in ppm), total suspended solids (TSS in ppm), biochemical oxygen demand (BOD5 in ppm), and chlorophyll-a (µg/L). In addition, researchers also recorded the density of P. crassipes in terms of individuals per square meter (ind/m2). The analysis was conducted to determine the Pollution Index (PI) and assess the water quality status using the NSF Water Quality Index (WQI) calculation method. The Pollution Index (PI) score categorizing the water quality as heavily polluted. The NSF-WQI analysis for the Bengawan Solo River at four sample points indicating moderate water quality. It can be concluded that the Bengawan Solo River at the study site is significantly polluted. The high density of P. crassipes, an alien invasive plant, has covered the entire water surface at all sampling locations. This phenomenon has negatively impacted water parameters. The data highlighting the urgency for more effective and sustainable management actions.