Keanekaragaman Plankton serta Hubungannya dengan Kualitas Air di Perairan Danau Toba Balige Kabupaten Toba Samosir

Abstract

The research about "The Diversity of Plankton and its Correlation to the Quality Water of Lake Toba, Balige, has been done in October 2008 to January 2009. Samples were taken from four observation Stations and in every observations station performed three times. Sample point was determined by using Purposive Random Sampling, samples were taken by using Plankton Net. Sample identification established in Ecology, laboratory of Biology study program, mathematics and Natural & science faculty of North Sumatera University, Medan. The result showed that 11 classes of Plankton which including 3 classes of Phytoplankton such as Bascillariophyceace, Chloirophyceace, Xanthophyceace and 8 classes of zooplankton such as Adenophora, Cyliata, Crustaceae, Fylosa, Granuloreticulosa, Lobosa, Monogononta and Turbellaria. The overflowing grade, relative density and the highest average presentation frequency found in station 2 form Tabellaria genera from Bacil/ariophyta class for about 1237,90 individu/L, 11, 77% and 100% whereas the overflowing grade, relative density and the lowest presentation frequency is derived from Rhopalodia genera form Bacillariophyta class, Desmidium and, Ulothyx genera from Chlorophyta class for amount 27,20 individu/L, 0,45% and 33,33%. The highest variety index grade is 3,27 found in Station 4 meanwhile the lowest variety index grade is 2, 71 found in Station 2. The highest similarity index is 1,98 found in Station 2 and the lowest is 1,89 found in Station 4. The water quality based on physical chemical nature, of Lake Toba Waterway according to PP No.82 year 2001 and Storet Method is in lowly to middle polluted and no polluted Correlation Pearson analysis showed that DO, COD, pH, temperature and oxygen saturation has negative correlation diversity of plankton. BOD5, NO3, PO4, Penetration of Light and Colifecal has positive correlation. The linier regretion can be concluded that station and deep to have influence the variety and the diversity of plankton.