KONDISI KUALITAS AIR HABITAT PESUT MAHAKAM (Orcaella brevirostris) DI WILAYAH DAERAH ALIRAN SUNGAI MAHAKAM, KALIMANTAN TIMUR

Abstract

Sungai Mahakam merupakan sungai terpanjang dan terbesar di Propinsi Kalimantan Timur dan menjadi habitat dari pesut (Orcaella brevirostris). Kondisi habitat diduga berkaitan dengan kecendrungan menurunnya populasi pesut, untuk itu perlu dilakukan penelitian mengenai kondisi kualitas air habitat pesut. Penelitian dilakukan di wilayah daerah aliran Sungai Mahakam, Kalimantan Timur pada bulan Oktober 2004 dan Oktober 2005 yang mewakili musim kemarau (air rendah) serta bulan Desember 2005 yang mewakili musim hujan (air tinggi) di 5 stasiun. Parameter kualitas air terdiri atas parameter fisika dan kimia yang dikompositkan dari lapisan bawah sampai dengan permukaan menggunakan water quality checker Horiba U-10. Secara umum, tipe perairan tergolong eutrofik dengan kondisi kualitas air yang tergolong aman diperuntukkan bagi habitat pesut.

Mahakam River is one of the longest and biggest river in East Kalimantan Province and becoming the habitat for Irrawady Dolphin, locally refers as Pesut (Orcaella brevirostris). It is important to understand about the condition of water quality that support the pesut habitat which has degradated. The sampling was conducted three times in Oktober 2004 and, October and December 2005 when it represented the low water and the high water condition’s respectivelly. At each sampling station physical and chemical parameters were analysed. Water samples were taken from each station as a composit samples taken from the bottom and surface layers and analysis was conducted using water quality checker Horiba U-10. In general, the locations of sampling station were classified as eutrophic water with most of the water quality would still meet the requirement for Irrawady Dolphin habitat.