ABSTRAKHilir Sungai Brantas mencakup kota Mojokerto, Kabupaten Sidoarjo, dan Kota Surabaya. Komoditas budidaya air tawar dengan volume produksi tertinggi di wilayah hilir Sungai Brantas adalah ikan lele. Sungai Brantas wilayah hilir telah mengalami penurunan kualitas air. Makrozoobentos dapat digunakan untuk mengetahui kualitas air. Penelitian ini menggunakan metode survei dengan analisis data secara deskriptif kuantitatif. Hasil penelitian ini menunjukkan nilai kelimpahan tidak merata dengan yang terendah 1% dan yang tertinggi 95,4%, sedangkan indeks keanekaragaman makrozoobentos yang didapatkan berkisar antara 0,187-1,267 yang masuk dalam keanekaragaman rendah sampai sedang dengan kategori tercemar sedang sampai berat. Substrat dasar yang didapatkan cukup beragam dikarenakan lokasi stasiun yang jauh serta kondisi sungai yang berbeda. Hasil pengukuran kualitas air di Sungai Brantas wilayah hilir, didapatkan suhu antara 25,5-28,9 oC, kecerahan antara 25-30 cm, pH antara 7,8-8, DO antara 3,1-5,2 mg/L, BOD antara 5,5-9 mg/L, COD antara 45-65 mg/L, dan TSS antara 400-900 mg/L.Kata kunci: Hilir, Sungai Brantas, kelimpahan, keanekaragaman, kualitas air.ABSTRACTThe downstream of the Brantas River includes Mojokerto city, Sidoarjo Regency and Surabaya city. The freshwater aquaculture commodity with the highest production volume in the lower reaches of the Brantas River is catfish. The downstream Brantas River has experienced a decline in water quality. Macrozoobenthos can be used to determine water quality. This study used a survey method with descriptive quantitative data analysis. The results of this study showed an uneven abundance value with the lowest being 1% and the highest being 95.4%, while the macrozoobenthos diversity index obtained ranged from 0.187 to 1.267 which is included in low to moderate diversity with moderate to heavily polluted categories. The basic substrate obtained is quite diverse due to the remote location of the stations and the different conditions of the river. The results of water quality measurements in the downstream Brantas River, obtained temperatures between 25.5-28.9 oC, brightness between 25-30 cm, pH between 7.8-8, DO between 3.1-5.2 mg/L, BOD between 5.5-9 mg/L, COD between 45-65 mg/L, and TSS between 400-900 mg/L.Keywords: Downstream, Brantas River, abundance, diversity, water quality.
Copyrights © 2025