Biomassa zoobentos, kandungan nutrien sedimen dan kualitas air berdasarkan zonasi di rawa Jombor, Kabupaten Klaten, Jawa Tengah

INDRAYANI, Ervina, Dr. Suwarno Hadisusanto

2008 | Tesis | S2 Biologi

Penelitian biomassa zoobentos, kandungan nutrien sedimen dan kualitas air berdasarkan zonasi telah dilakukan di Rawa Jombor, Kabupaten Klaten, Jawa Tengah. Pengambilan sampel dilakukan bulan Juni 2007 - Juli 2008. Digunakan 3 zonasi, 3 stasiun, dengan 5 ulangan. Sampel air diambil dengan Kemmerer water sampler volume 1 L dan pengambilan substrat dengan vertical core sampler dengan panjang 3 m, diameter 2,5 inchi. Analisis kualitas air dilakukan di Laboratorium Hidrologi, Fakultas Geografi dan analisis substrat dilakukan di Laboratorium Tanah, Fakultas Teknologi Pertanian, UGM. Identifikasi dan pengukuran biomassa zoobentos dilakukan di Laboratorium Ekologi, Fakultas Biologi, UGM. Kemelimpahan zoobentos dianalisis dengan Indeks Diversitas Simpson dan keanekaragamannya diukur dengan Indeks Diversitas Shannon-Wiener. Data dianalisis dengan korelasi dan regresi ganda bertahap untuk mengetahui pengaruh zonasi terhadap biomassa zoobentos taraf uji 10%. Hasil penelitian menunjukkan bahwa biomassa zoobentos berbeda berdasarkan zonasi pada p < 0,1. Rerata biomassa tertinggi di zona eceng gondok = 0,0119 g/cm³/bulan, zona warung apung = 0,0073 g/cm³/bulan dan terendah pada zona tambak = 0,0071 g/cm³/bulan. Indeks Shanon-Wiener menunjukkan keanekaragaman spesies zoobentos di Rawa Jombor rendah, berkisar antara 0,91 – 0,98. Indeks Diversitas Simpson menunjukkan bahwa kemelimpahan spesies rendah, berkisar antara 0,02 – 0,086. Dalam penelitian ini ditemukan 22 spesies zoobentos anggota dari Crustaceae, Gastropoda, Insecta dan Annelida. Hasil analisis regresi berganda bertahap menunjukkan bahwa biomassa zoobentos sangat dipengaruhi oleh N-total sedimen (β=-0,158), P-total sedimen (β=-0,235), jumlah partikel terlarut (TSS, β=0,192) dan temperatur air (β=0,296). Sementara, kemelimpahan spesies zoobentos dipengaruhi oleh N-total sedimen (β=-0,372), P-total sedimen (β=-0,314) dan TSS (β=0,352). Kualitas air di Rawa Jombor masih tergolong normal, sehingga Rawa Jombor digolongkan ke dalam perairan oligotrofik yang mengarah ke mesotrofik.

The research on the zoobenthos biomass, sediment nutrient content and water quality based on zonation has been carried out in the Jombor Swamp, Klaten Regency, Central Java. Sampling was taken at June 2007 – July 2008. It is used 3 zonation, 3 stations, and 5 repetition. Water sample was taken in Kemmerer water sampler 1 L and taking substrate in vertical core sampler by length 3 m, with 2,5 inch in diameter. Water quality analysis was made at Laboratory of Hydrology, Faculty of Geography, UGM and substrate analysis was made at Laboratory of Soil, Faculty of Agriculture Technology, UGM. Identification and measuring zoobentos biomass was made at Laboratory of Ecology, Faculty of Biology, UGM. The zoobenthos abundance was analyzed with the Simpson Diversity Index and zoobenthos diversity was measured with Shannon-Wiener’s Diversity Index. Furthermore, correlation and stepwise linear regression analysis was made to detect the influence of zonation toward zoobentos biomass with examination test 10%. The result shows that zoobentos biomass is different based on zonation at p < 0,1. The highest biomass at the water hyacinth zone = 0,0119 g/cm3/month, at the restaurant zone = 0,0073 g/cm/month and the lowest biomass at the fishpond zone = 0,0071 g/cm3/month. Shannon-Wiener Index show that the diversity of zoobenthos species is lower, that is 0,91 – 0,98. The Simpson Diversity Index indicates that the species abundance is lower, that is 0,02 – 0,086. In this research found 22 zoobenthos species that was Crustaceae, Gastropoda, Insecta and Annelida members. Stepwise linear regression showed that zoobenthos biomass affected by total-N of sediment (β=-0,158), total-P of sediment (β=-0,235), total solved solution (TSS, β=0,192) and water temperature (β=0,296). The abundance of zoobenthos spesies affected by total-N of sediment (β=-0,372), total-P of sediment (β=-0,314) and TSS (β=0,352). The water quality at the Jombor Swamp is still normal in category, thus the Jombor Swamp is categorized into oligotrofic waters that direct to mesotrofic.

Kata Kunci : Biomassa,Zoobentos,Kandungan nutrien,Kualitas air,Zonasi, zoobentos, biomass, nutrient content, water quality, zonation