ANALISIS DEGRADASI LINGKUNGAN PERAIRAN DAN KETERKAITANNYA DENGAN KEMATIAN MASSAL IKAN BUDIDAYA DI WADUK CIRATA, JAWA BARAT

Abstract

Waduk Cirata dimanfaatkan untuk budidaya ikan dengan sistem keramba jaring apung, dimana jumlah keramba saat ini sudah melebihi daya dukung yang menyebabkan kelebihan hara (eutrofikasi). Di Waduk Cirata setiap tahun terjadi kematian ikan hasil budidaya. Penelitian ini bertujuan untuk mengidentifikasi masalah kematian masal ikan di Waduk Cirata. Pengumpulan data dilakukan pada saat terjadi kematian massal ikan akhir September 2017, di Zona I (Sangkalin, Cipicung-Bandung Barat), Zona II (Cimanggu-Purwakarta), dan Zona III (Jatinengang, Patokbeusi-Cianjur) menggunakan metode observasi cepat in situ, wawancara dan studi pustaka. Parameter yang diamati meliputi: Suhu air / udara, Kedalaman perairan, Warna air, Kecerahan, Kekeruhan, TDS (0,046-0,172 mg/l), TSS (total suspended solid), DHL (0,1-0,3 mS/cm), Oksigen terlarut, ORP (-49 sampai 244 mv), bebas CO2, Alkalinitas, pH, Nitrat, Nitrit, Amonium, Fosfat, Sulfat, BOT (5,06-17,06 mg/l), dan Kronologi kematian massal ikan. Hasil penelitian menunjukkan bahwa, kadar Oksigen terlarut dibawah 4 mg/l dan ORP nilainya negatif sehingga perairan tidak mampu menguraikan akumulasi limbah sebesar 390.848 ton/tahun. Kondisi tersebut mengindikasikan bahwa perairan mengalami degradasi, Degradasi lingkungan perairan dipicu oleh fenomena umbalan menyebabkan kematian massal budidaya ikan sekitar 65 ton (Zona III), 25 ton (Zona II), dan 20 ton (Zona I).

The Cirata reservoir is used for fish culture by floating net cage system that currently has been exceeded to its carrying capacity that caused an over nutrient (eutrophication). Every year, mass mortality event occurred in Cirata Reservoir. This research aims to identify the causal of mass mortality event in the Cirata reservoir. This research conducted at the end of September 2017 in several locations: Zone II (Cimanggu-Purwakarta), Zone I (Sangkalin, Cipicung-West Bandung), and Zone III (Jatinengang, Patokbeusi-Cianjur). A rapid in situ observation, interview and literature review. Parameters that measured include Water/air temperature, Depth, Watercolour, Brightness, Turbidity, TDS (0,046-0,172 mg/l), TSS (total suspended solid), DHL (0,1-0,3 mS/cm), Dissolved Oxygen, ORP ((-49 to 244 mv), CO2, Alkalinity, pH, Nitrate, Nitrite, Ammonium, Phosphate, Sulphate, BOT (5,06-17,06 mg/l), and the chronology of mass mortality. The results showed that the dissolved oxygen was less than 4 mg/l and negative ORP value that indicated incapability of environment to decompose the feed accumulation waste (about 390.848 tons/year). The degradation of waters environment triggered by upwelling phenomenon could cause mass mortality event on fish culture in three zones about 65 tons (Zone III), 25 tons (Zone II) and 20 tons (Zone I), respectively.