DEKOMPOSISI BAHAN ORGANIK PADA SEDIMEN DI AREA MANGROVE PESISIR MOROSARI, KABUPATEN DEMAK PADA SKALA LABORATORIUM Decomposition of Organic Materials on Sediments in the Mangrove Area of Morosari Coast, Demak Regency on a Laboratory Scale
Authors: Andriyanto Wulan Oktaviasari , Purnomo Pujiono Wahyu , Rahman Arif 
Published: September 2020

ABSTRAK Ekosistem mangrove di pesisir Morosari, Kabupaten Demak merupakan salah satu ekosistem mangrove yang berfungsi sebagai kawasan konservasi dan kawasan wisata bahari. Salah satu sumber bahan organik pada ekosistem mangrove berasal dari serasah daun mangrove yang berguguran jatuh bercampur dengan sedimen dan menghasilkan unsur hara sebagai sumber nutrien Tujuan penelitian ini adalah untuk mengetahui hubungan konsentrasi nitrat, bahan organik, nitrit, dan total bakteri serta mengetahui perbedaan proses dekomposisi bahan organik yang terjadi di pesisir Morosari, Kabupaten Demak. Penelitian dilaksanakan pada bulan Desember 2018 di Laboratorium Biologi FPIK Universitas Diponegoro, Semarang. Metode yang digunakan dalam penelitian ini adalah metode eksperimental di laboratorium dengan membandingkan media sedimen di dalam area mangrove dan luar area mangrove kemudian diisi air laut. Perlakuan pertama akuarium A diisi dengan sampel sedimen dari dalam area mangrove sedangkan akuarium B diisi dengan sampel sedimen dari luar area mangrove masing- masing ± setinggi 5 cm. Setelah itu sampel air laut dimasukan setinggi ± 15 cm ke dalam masing-masing akuarium dan ditambahkan aerator. Variabel yang diukur adalah nitrat, nitrit, bahan organik dan total bakteri kemudian diukur dan diamati setiap tiga hari sekali. Analisa data menggunakan metode regresi linier berganda. Hasil yang diperoleh yaitu konsentrasi nitrat berkisar antara 9,69–18,10 mg/l, nitrit 0,01–3,44 mg/l, bahan organik 10,25–21 mg/l dan total bakteri 950–24.000 CFU/ml. Hubungan nitrat dengan bahan organik dan total bakteri menunjukan terdapat hubungan yang kuat yang berpengaruh signifikan. ABSTRACT The mangrove ecosystem in Morosari coast, Demak Regency is one of the mangrove ecosystems which is a marine tourism area. One of the organic material source in the mangrove ecosystem comes from the mangrove leaf litter that falls and mixed with sediment and produces nutrients as a source of nutrition. The purpose of this study was to determine the correlation of nitrate concentration, organic matter, nitrite, and total bacteria and also to know the differences in the process of decomposition of organic matter that occurred in Morosari coast, Demak Regency. This research was conducted in December 2018 at the Biology Laboratory of FPIK, Diponegoro University, Semarang. The method used in this study was an experimental in the laboratory by comparing the types of sediment in the mangrove area and outside the mangrove area and filled with sea water. The first aquarium A treatement was filled with sediment sample from mangrove area, meanwhile aquarium B was filled with sediment sample from the outside of mangrove area with the height of ± 5cm each. Sea water samples was entered as high as ± 15 cm into each aquarium and added the aerator. The measured variable are nitrate, nitrite, organic matter and total bacteria and observed every three days. Data analysis using multiple linear regression methods.The results obtained, nitrate concentrations range from 9.69-18.18 mg/l, nitrite 0.01-3.44 mg/l, organic matter 10.25-21 mg/l and total bacteria 950-24,000 CFU ml. The correlation between nitrate and organic matter and total bacteria shows that there is a strong correlation that has a significant effect.