HUBUNGAN ANTARA STRUKTUR KOMUNITAS PLANKTON DAN TINGKAT PENCEMARAN DI SITU GUNUNG PUTRI, KABUPATEN BOGOR

Abstract

Relationship between Plankton Community Structure and Pollution Level in Gunung Putri Pond, Bogor Regency. Gunung Putri Pond is located in Gunung Putri Village, of Bogor Regency. Its location is in front of the Gunung Putri toll gate. Its current condition, overgrown by water hyacinth, is the reason it was chosen as the research object. The purpose of this study was to determine the level of water pollution through the saprobity index in Gunung Putri Pond based on the plankton community. The research was conducted from February to March 2019 in Gunung Putri Pond and at the Research Center for Limnology, Indonesian Institute of Sciences in Cibinong. The method used is a survey method, in the form of observation and measurement of physics and chemical parameters of the water. Plankton samples were taken using a purposive sampling method in accordance with the research objectives, while the plankton was counted using the Sedgwick Rafter method. The results of the study indicated plankton diversity consisting of four phytoplankton phyla: Cyanophyta, Euglenophyta, Chlorophyta, and Chrysophyta as well as two zooplankton phyla: Arthropoda and Zooflagellata. The phytoplankton diversity index value of 0.6 and zooplankton of 0.7 indicated that the environmental conditions were able to well support the life of organisms and the environment was in a balanced or stable state which characterized a stable community. The phytoplankton dominance index was 0.76 and zooplankton dominance index was 0.74. These high dominance index values indicated the presence of individuals who dominated the waters. The phytoplankton that dominated Gunung Putri Pond was the genus Phacus sp. from the phylum Euglenophyta, while the dominant zooplankton was the genus Brachionus sp. from the phylum Arthropoda. The saprobity index can be related to the level of pollution, and can also indicate the types of pollutants entering the water. The obtained value of saprobity index is 0.16 which is included in the β/α mesosaprobic phase. This indicates that Gunung Putri Pond waters are experiencing moderate levels of pollution and the pollution that occurs comes from organic and inorganic pollutants.