A study on water pollution level in Sentani Lake, Irian Jaya

Lake Sentani have 32 fish species, in which 11 species are indigenous. There are 2 endemic species of Rainbow or pelangi and locally called Kaskado, Glosolepis incisus and Chilatherina sentaniensis. The rainbow fishes are endemic and indigenous so the habitat need to be protected. This study was to determine the pollution level in Sentani Lake and assess the people's knowledgibility and attitude about the lake condition. The study was also expected to be able to provide the water quality data in association with the pollution level as a result of human activities around the lake and the knowledgibility and attitude of people about lake pollution. The study was conducted through a survey technique, for field observation and water sampling, and interview. Data collection was done through several level, i.e. preparation, equipment test and data recording (primary and secondary). Water was collected from four zones, zone I (Yoka/East Sentani), II (Hobong/Central Sentani), III (Doyo lama/West Sentani, and IV (Selat Bukiomasolo/South Sentani) using Kemmerer Water Sampler at a one meter depth, because the water quality parameter for vertical distribution are relatively homogen. This vertical layer are intensively used for several activities by the people around Lake Sentani. Analyses of the physical, chemical and biological elements were conducted at Balai Laboratorium Kesehatan Rumah Sakit Umum (Health Laboratory Institute of General Hospital) Dok II Jayapura. Water quality data were compared to those of the national standard environment for various importance according to the Indonesian Government Regulation No. 20 1990, concerning the water pollution control, and those of the national standard of liquid wastes according to decree N.416/MENKES/PERIX/1990 about the water requirement and quality control. The biological indicators were measured at the aquatic animal density (Michael, 1995). In addition, the people's knowledgibility and attitude on the environmental pollution and water quality were analyzed using the interviewed quantitatively data. Water quality analyses showed that in several location, the nitrite and plumb content have exceeded the standard water safety, and the dissolved oxygen been below the safe concentration, both for B and C classification. Nevertheless, the water quality status of Sentani Lake is physically not worse than that of the standard requisites for B and C classification yet. The microbiology parameters also are still in the safe ranges for B classification. Furthermore, field observation indicated that 70 percent of the people's knowledgibility on pollution is good, 23 percent fair and 6.7 percent poor. People knowledge on pollution are highly associated with their formal and non-formal education levels and into they gained from the related institutions or LSM. For people with non-formal education levels, the knowledge was gained from the related institutions or LSM only. The non-formal course would be increase people's awareness of the sustainable lake utilization