SAPROBITAS PERAIRAN SUNGAI JUWANA BERDASARKAN BIOINDIKATOR PLANKTON

Abstrak

Sungai Juwana merupakan sungai terbesar dan terpanjang di Kota Pati. Berkembangnya kegiatan penduduk di Daerah Aliran Sungai (DAS) Juwana dapat mempengaruhi kualitas air sungai. Penelitian ini menggunakan rancangan eksplorasi dengan metode survai, dan penetapan stasiun pengambilan sampel dengan metode purposive sampling. Penempatan stasiun didasarkan atas perkiraan beban pencemar yang masuk ke sungai. Stasiun 1 berada hulu sebagai pembanding, stasiun 2 sumber limbah pabrik tahu dan pertanian, stasiun 3 sumber limbah industri kacang, stasiun 4 sumber limbah industri peleburan timah, stasiun 5 limbah ikan dari TPI serta pelabuhan, dan stasiun 6 berada di hilir sungai (dekat muara). Pengambilan sampel dilakukan sebanyak 3 kali dengan selang waktu 2 minggu. Hasil penelitian ditemukan 10 jenis plankton terdiri dari 3 jenis kelompok α-Mesosaprobik, 2 jenis kelompok β-Mesosaprobrik dan 5 jenis kelompok non saprobik, kemudian diinterpretasikan pada tabel hubungan antara koefisien saprobitas perairan dengan tingkat pencemaran perairan. Berdasarkan perhitungan dan analisis nilai koefisien saprobik dari stasiun 1 sampai hilir didapatkan nilai koefisien saprobik plankton berkisar antara -0,6 s/d -1. Berdasarkan kriteria tingkat pencemaran menunjukkan bahwa Sungai Juwana berada dalam kondisi tercemar sedang sampai dengan cukup berat.Juwana River is the largest and longest river in the city of Pati. The developing activities in the watershed Juwana can affect water quality. Exploratory study used a survey method, where the determination of sampling stations using purposive sampling. The settlement of the stations was conducted based on the estimated pollutant loads into the river, the first station was located in the upstream of the river, as comparison the second station was located nearby peanut industry, next the fourth station was located in the tinmelting industrial wastes, the fifth station was located in the fish market and nearby the Harbour, the last, sixth station was located in the downstream of the river. Sampling performed 3 times with an interval of 2 weeks. In this research, it has found that is 10 species of plankton consist of 3 species group α-Mesosaprobic, 2 species group β-Mesosaprobrik and 5 species group non saprobik, and than interpreted the relationship between the coefficient table saprobitas waters with levels of water pollution. Based on the calculation and analysis of the saprobic coefficient values station 1 to downstream obtainet plankton saprobic coefficient values ranged from -0.6 s / d -1. Based on these criteria indicate that the level of pollution in Juwana River is moderate to high.