KELIMPAHAN Parathelphusa convexa SEBAGAI SALAH SATU PARAMETER BIOINDIKATOR KUALITAS PERAIRAN SUNGAI LUJUNG DAN HULU SUNGAI KLAWING, KECAMATAN BOBOTSARI, PURBALINGGA

Abstract

This study aims to determine the abundance of Parathelphusa convexa as a bioindicator parameter in the upstream river waters. The Lujung River, similar to the upstream Klawing River, is a river extensively utilized by local communities. Anthropogenic activities contribute inputs to both river flows, thereby influencing their water quality. As the most frequently found crustacean organism in these rivers, P. convexa is inevitably affected by these water runoffs. The study was conducted using a survey method with purposive random sampling. Five stations were designated as observation sites, comprising two stations in the Klawing River area, two stations in the Lujung River area, and one station at the Lujung River estuary entering the Klawing River. Each station exhibited distinct runoff characteristics — influenced by agricultural fields and plantations at Stations 1 and 3, residential areas at Stations 2 and 4, and forest at Station 5. Descriptive interpretation revealed mean abundances across Stations 1 to 5 as 2, 5, 4, 3, and 5 individuals/m², respectively. Abundance was correlated with water quality parameters including temperatur and total dissolved solids (TDS). Temperatur ranged from 25.53 to 26.77°C, while TDS varied between 72 and 78.33 mg/L. Both parameters indicated good upstream water characteristics, free from pollution. Abundance showed a significant correlation with TDS (P value < 0.05), but not with temperatur. The strong correlation between abundance and TDS supports the conclusion that P. convexa can serve as a bioindicator of unpolluted upstream waters.