Keanekaragaman Makrozoobentos Dan Hubungannya Dengan Kualitas Air Di Sungai Bedagai Kabupaten Serdang Bedagai Provinsi Sumatera Utara

Abstract

Serdang Bedagai Regency, which is one of the regencies in the East Coast of North Sumatra, which consists of 17 sub-districts and 243 villages/kelurahan. Bedagai River is a river that is used by the surrounding community to carry out various activities ranging from agricultural activities, washing clothes, and household waste disposal so that it can cause a decrease in water quality in the Bedagai River. The presence of macrozoobenthos can generally describe the condition of the waters, so its presence is often used as an indicator of decreasing water quality. The aim of the research was to determine the water quality of the physical and chemical parameters associated with the diversity of macrozoobenthos. This research was conducted from October to January 2022 in Bedagai River, Serdang Bedagai Regency, North Sumatra Province. Water quality measurements were analyzed using the Storet Index, Pollution Index, and CCME based on water quality standards according to Government Regulation No. 22 of 2021, while the ABC curve was analyzed by comparing density and biomass. The method of determining the research station is purposive random sampling, namely by selecting three research stations based on environmental conditions that are considered appropriate to the research objectives. The selection of stations was based on the differences in activities on the Bedagai River. The results of this study concluded that the water quality based on the Pollution Index method of Stations I, II, and III was classified as lightly polluted. Based on the Storet Method Stations I, II, and III are classified as heavily polluted. Based on the CCME Method, Stations I, II, and III are classified as very bad. Based on the ABC curve analysis, Stations I, II, and III are classified as moderately polluted. The water quality based on the ABC Curve method at stations I, II and III is classified as moderately polluted with overlapping density and biomass curves. The CCME method has higher sensitivity than the storet method and the pollution index method.

Kabupaten Serdang Bedagai yang merupakan salah satu Kabupaten yang berada di kawasan Pantai Timur Sumatera Utara yang terdiri dari 17 Kecamatan dan 243 Desa/Kelurahan. Sungai Bedagai merupakan sungai yang dimanfaatkan oleh masyarakat sekitar untuk melakukan berbagai aktivitas mulai dari aktivitas pertanian, kegiatan mencuci pakaian, serta tempat pembuangan sampah rumah tangga sehingga dapat menyebabkan penurunan kualitas air di Sungai Bedagai. Keberadaan makrozoobentos umumnya dapat menggambarkan kondisi perairan, sehingga keberadaannya sering dijadikan indikator penurunan kualitas perairan. Penelitian yang dilakukan bertujuan untuk mengetahui kualitas air parameter fisika dan kimia yang dikaitkan dengan keanekaragaman makrozoobentos. Penelitian ini dilaksanakan pada bulan Oktober sampai Januari 2022 di Sungai Bedagai Kabupaten Serdang Bedagai Provinsi Sumatera Utara. Pengukuran kualitas air dianalisis dengan Indeks Storet, Indeks Pencemaran, dan CCME berdasarkan baku mutu kualitas air menurut Peraturan Pemerintah Nomor 22 Tahun 2021, sedangkan kurva ABC dianalisis dengan membandingkan kepadatan dan biomassa. Metode penentuan stasiun penelitian adalah purposive random sampling yaitu dengan cara memilih tiga stasiun penelitian berdasarkan kondisi lingkungan yang dianggap sesuai dengan tujuan penelitian. Pemilihan stasiun didasarkan karena adanya perbedaan aktivitas yang ada di Sungai Bedagai. Hasil penelitian ini menyimpulkan bahwa kualitas air berdasarkan metode Indeks Pencemaran Stasiun I, II, dan III tergolong tercemar ringan. Berdasarkan Metode Storet Stasiun I, II, dan III tergolong tercemar berat. Berdasarkan Metode CCME Stasiun I, II, dan III tergolong sangat buruk. Berdasarkan analisis kurva ABC Stasiun I, II, dan III tergolong tercemar sedang. Kualitas air berdasarkan metode Kurva ABC stasiun I, II dan III tergolong tercemar sedang dengan kurva kepadatan dan biomassa yang saling tumpang tindih. Metode CCME lebih tinggi sensitivitasnya dibandingkan metode storet dan metode indeks pencemaran.