Analisis Kualitas Air dan Hubungannya dengan Keanekaragaman Vegetasi Akuatik di Perairan Parapat Danau Toba

Abstract

The analysis of water quality and the correlation with the aquatic vegetation diversity has been analyzed in January 2008-April 2008. The method in determining the sample location is “Purpose Random Sampling”. The analysis of water quality can bee seen based on the physical-chemical content which analyzed in The Center of Environment Effect (PUSLITDAL) and identification of aquatic vegetation sample perform in the Ecology laboratory of FMIPA North Sumatera University. The result of this research showed physical–chemical nature of Lake Toba Waterway (BOD5, COD, Phosphate, NO3-N, Ammonia) based on PP No. 82 year 2001, has passed the threshold of water quality for Type 1 therefore the Lake Toba Waterway particularly Parapat area included in middle and high polluted and cannot be used as drinking water. In Lake Toba Waterway showed 8 species aquatic vegetation such as, Eichhornia crassipes, Nelumbo lutea, Peltandra virginica, Hydrilla verticillata, Pistia stratiodes, Ipomoea aquatica, Marsilea villosa and Typha angustifolia. The analysis percentage of density and presentation frequency showed result that dominant species in Lake Toba Waterway is Hydrilla verticillata (with Importance Value Index about 80, 04% to 81, 88%. The aquatic vegetation diversity Index get value for about 1, 06 – 1, 33. Diversity index 0, 68 –0, 97. Similarity index for about 40%. The result of Pearson correlation test showed that COD, temperature, ammonia correlated or same course with real effect toward of aquatic vegetation diversity in Lake Toba Waterway.

Analisis kualitas air dan hubungannya dengan keanekaragaman vegetasi akuatik telah diteliti pada bulan Januari 2008-April 2008. Metode yang digunakan dalam menentukan lokasi pengambilan sampel adalah “Purpose Random Sampling”. Analisis kualitas air dilihat dari kandungan faktor fisik kimia air yang dianalisis di Puslit SDAL Universitas Sumatera Utara. Identifikasi sampel vegetasi akuatik dilakukan di Laboraturium Ekologi FMIPA Universitas Sumatera Utara Hasil penelitan menunjukkan sifat fisika – kimia perairan Danau Toba (BOD5, COD, fosfat,NO3-N, Amonia) berdasarkan PP No 82 tahun 2001,telah melewati ambang batas baku mutu air untuk golongan I sehingga perairan Danau Toba khususnya kawasan Parapat tercemar sedang sampai berat sehingga tidak layak di jadikan sebagai sumber air minum. Di perairan Danau Toba ditemukan 8 spesies vegetasi akuatik yaitu Eichhornia crassipes, Nelumbo lutea, Peltandra virginica, Hydrilla verticillata, Pistia stratiodes, Ipomoea aquatica, Marsilea villosa dan Typha angustifolia. Analisis persentase dari kerapatan dan frekwensi kehadiran diperoleh hasil bahwa spesies yang dominan di perairan Danau Toba adalah Hydrilla verticillata dengan Indeks Nilai Penting berkisar 80,04% sampai 81,88%. Indeks keanekaragaman vegetasi akuatik diperoleh nilai berkisar 1,06 – 1,33, Indeks keseragaman 0,68 – 0,97, Indeks similaritas sebesar 40%. Hasil uji korelasi Pearson menunjukkan bahwa COD, temperatur dan amonia berpengaruh nyata terhadap keanekaragaman vegetasi akuatik yang terdapat di perairan Danau Toba