Determination of Trophic Status Based on Chlorophyll-a in Cikidang River Pangandaran, West Java – Indonesia

Abstract

Trophic status is an indicator of water fertility. In general, there are 3 classifications of trophic status, namely oligotrophic, mesotrophic and eutrophic [1]. According to Linus et al. [2] Chlorophyll-a phytoplankton is often used as an indicator of water quality and water fertility status. This research is to determine the trophic status of the waters based on the concentration of chlorophyll-a in the Cikidang Pangandaran river for the development of fisheries management. The research was conducted from November 2021 - January 2022. The method used was a survey method with a purposive sampling technique. The results showed that the concentration of chlorophyll-a ranged from 3.10-7.77 mg/m3. So it can be said that the trophic status of the Cikidang River is mesotrophic or moderate fertility. Parameters of supporting water quality are temperatures ranging from 26.75-29.570C, Light Transparency ranging from 16.12-135.75 cm, pH ranging from 7.38-7.48, Carbon dioxide ranging from 19.8-47.3 mg/L, BOD ranging from 10.41-16.36 mg/L, DO range from 4.38-5.06 mg/L, Nitrates ranged from 0.25-0.37 mg/L and Phosphate ranged from 0.009-0.02975. The water quality in the Cikidang River generally meets the requirements of class II and III quality standards according to Government Regulation Number 22 of 2021 concerning the Implementation of Environmental Protection and Management, so it is still supportive for the survival of fish resources.