Pollution level of Banjaran River, Banyumas District, Indonesia: A study based on the Saprobic Index of periphytic microalgae

Abstract

Abstract. Samudra SR, Fitriadi R, Baedowi M, Sari LK. 2022. Pollution level of Banjaran River, Banyumas District, Indonesia: A study based on the Saprobic Index of periphytic microalgae. Biodiversitas 23: 1527-1534. The saprobic index of periphytic microalgae can be used to determine the level of water pollution based on the number and composition of species. Banjaran River is one of the rivers in the Banyumas District, Central Java, Indonesia, which is widely used by the local people for daily activities. The increase of domestic and agricultural activities in the river triggers an increase in the pollutants input into the river. This study aims to determine the status of the waters in the midstream of Banjaran River by using the periphytic microalgae saprobic index as a bioindicator of water quality. Purposive sampling method was used in this study by establishing four stations and five replications at each station. The result showed that the abundance of periphytic microalgae ranged from 7,547-8,733 cells/cm2; the diversity index ranged from 1.64-2.07 (moderately polluted waters); the dominance index ranged from 0.21-0.26 (no particular species of periphytic microalgae dominating the four stations); and saprobic index value of Banjaran River ranged from 1.00 to 1.03 which indicates that Banjaran River belongs to ?-meso/oligo saprobic water. In other words, it was water with a light pollution level. An action to reduce organic pollution is necessary, one of which is by reducing the people's activities such as washing and disposing of household waste into the river so that the condition of Banjaran River can be maintained properly and reduce pollution in its subsequent river flows.