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"Danau Maninjau diketahui memiliki aktivitas KJA yang intensif dan fenomena kematian massal ikan di perairan tersebut sering terjadi. Tubo Belerang", adalah istilah yang ditandai dengan adanya kematian massal ikan yang dipelihara pada karamba jaring apung (KJA) di Danau Maninjau. Untuk mengenali indikasi "tubo Belerang" di Danau Maninjau, telah dilakukan pengamatan pola stratifikasi beberapa parameter kualitas air, meliputi suhu, oksigen terlarut (DO; Dissolved Oxygen) dan kadar bahan organik total (TOM; Total Organic Matter). Pengamatan dilakukan pada Agustus, Oktober, Desember 2011 dan Maret 2012 di lima stasiun yang berbeda, pada strata 0 , 25, 50, 75, 100, 125 dan 150 m, yang disesuaikan dengan kedalaman masing-masing stasiun. Pada Desember 2011 dan Maret 2012, parameter DO diukur pada kedalaman 5, 10, 15 dan 20 m. Sebagai paremeter pendukung, diukur kandungan klorofil pada kedalaman 0, 1,5, 3,0 dan 4,5 m, kedalaman Secchi, dan juga kadar total fosfor (TP) dan total nitrogen (TN) pada lapisan permukaan. Berdasarkan kadar klorofil, kedalaman Sechi, kadar TP dan TN, perairan Danau Maninjau menunjukkan kondisi eutrofik. Suhu air relatif stabil pada kedalaman di bawah 25 meter, kondisi anoksik ditemukan pada lapisan air hingga kedalaman 15 m. Kadar TOM berkisar 5,9-24,9 mg/L, dan tidak ada pola khas pada distribusi vertikal TOM. Kondisi ini secara umum sering digambarkan sebagai upwelling tetapi sebenarnya merupakan proses turnover."

"Danau Maninjau merupakan salah satu danau di Indonesia yang dimanfaatkan untuk budidaya ikan dengan karamba jaring apung (KJA). Kegiatan KJA pada umumnya menjadi kontroversi antara kebutuhan ekonomi masyarakat dan kelestarian lingkungan, serta antara target pencapaian produksi ikan dan daya dukung perairan. Penelitian ini bertujuan mengamati pola distribusi oksigen terlarut (DO; Disolved Oxygen) di wilayah KJA di Danau Maninjau, dan bagaimana kaitannya dengan kadar organik dan kadar klorofil di dalam air. Pelaksanaan penelitian dilakukan pada dua periode, yaitu bulan Oktober 2009 dan Maret 2010. Kondisi kualitas air Danau Maninjau yang cukup nyata adalah tingkat kecerahan rendah (maksimum < 3,5 m), kadar klorofil cukup tinggi (0,005 - 0,012 mg/L), kadar Total Phosphor (TP) dan Total Nitroten (TN) cukup tinggi, yang mencirikan kondisi perairan eutrofik, demikian pula kadar bahan organik total (TOM; Total Organic Matter) menujukkan kadar yang cukup tinggi. Pola oksigen terlarut harian menunjukkan kondisi yang beragam, dengan kadar DO maksimum antara pukul 06.00 dan pukul 18.00 dan kadar yang relatif aman bagi kehidupan biota hanya sampai kedalaman 5 meter. Fluktuasi harian tersebut tampak bahwa ketersediaan DO sangat dipengaruhi aktivitas fotosintesis. Kadar DO meskipun tidak secara nyata, tampak menurun dengan bertambahnya kadar bahan organik pada kolom air."

"Waduk resapan Universitas Indonesia (UI) telah dibangun sejak 5 tahun yang lalu. Namun kegiatan monitoring dan evaluasinya sangatminim dilakukan. Tujuan dari studi ini adalah untuk mengetahui laju resapan, dan untuk mengevaluasi kondisi kuantitas dan kualitas air waduk resapan selama musim kemarau dan penghujan. Pengukuran kedalaman muka air, intensitas curah hujan dan penguapan dilakukan untuk menentukan ketersediaan air, laju resapan, dan imbangan air waduk. Sejumlah air permukaan diambil dari waduk resapan dan sungai di tiga titik sampling untuk mengetahui kondisi kualitas air eksisting. Hasil studi menunjukkan tidak ada perbedaan yang signifikan antara laju resapan musim kemarau (3,2 mm/hari) dan musim penghujan (6,1 mm/hari). Imbangan air waduk resapan menunjukkan nilai yang berlimpah. Berbagai parameter fisik dan kimia air (kekeruhan, warna, TDS, pH, dan Cl) mempunyai konsentrasi di bawah standarbaku mutu. Temuan dari studi ini antara lain bahwa air permukaan waduk masih layak untuk diimbuhkan ke dalam lapisaquifer sehingga mendukung keberlanjutan gerakan konservasi air, dan ketersediaannya sangat berpotensi untuk dikembangkan sebagai sumber air baku tambahan bagi kebutuhan air domestik di lingkungan Kampus UI Depok.

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AbstractThe UI recharge pond has been constructed 5 years ago. However, monitoring and evaluation activities on its performances are very lack. Aims of this study are to understand the recharge rate, and to evaluate existing quantity and water quality of the pond during dry and rainy season. Measurement of water depth, rainfall intensity, and evaporation is conducted to determine water availability, recharge rate, and water balance of the recharge pond. Amount of surfacewater is collected from recharge pond and river at three sampling point to determine existing water quality of the pond. The results showed that recharge rate of the pond between dry season (3.2 mm/day) and wet season (6.1 mm/day) are considered as insignificant different. The water balance of the recharge pond shows an excessive rate. Various physics and chemical parameters (turbidity, color, TDS, pH, and Cl) are found to have concentration lower than the waterquality standard. The results suggest that the pond surface wateris remain suitable to be recharged into aquifer zone so that sustaining ground water conservation campaign, and it is potential to be utilized as an additional raw water source for domestic water demand of UI Campus Depok. "

"The lakes in urban megacity Jakarta, called as ?setu or situ? by the local people, play a central role in integrated water resources management. Despite its pivotal role in maintaining the balance of urban water system, they have not received sufficient attention. Rapid urban development in a very distinct urban watershed type of lake?s surroundings has impacted on the water quantity and quality of urban lakes in megacity Jakarta. Chronic problems faced by downstream area in megacity Jakarta such as flash floods in the rainy season and water scarcity in the dry season have indicated that the lakes have not been managed and functioned well. Human and nature disturbances such as shoreline encroachment, shoreline erosion, garbage dump and inflow from untreated sewage and urban runoff have polluted the lake water and reduced its volume capacity. Nearly half of the existing lakes have reduced from 10 to > 50% of its water volume capacity due to lake area shrinkage, siltation and even excessive growth ofinvasive macrophytes. The lakes are mostly in disturbed to damaged environmental conditions. Lakes in urban and rural villages have less in water quantity and higher solids, organic matter, nutrients and even fecal bacteria concentrations than the lakes in planned residential, high-rise residential and industrial areas types of urban surroundings. As the lakes in the urban village and industrial area, elevated toxic metal concentrations have become public concern due to lake hygiene problems. Elevated nutrient concentrations have caused the lake eutrophication, where some lakes have suffered from excessive macrophyte coverage, algal bloom even toxic cyanobacterial bloom. The urban lakes in megacity Jakarta constantly have been degrading physically and ecologically affecting its water quantity and quality which is increasing the threat to human?s health and impact future human?s resilience in urban megacity Jakarta."

"Cage aquaculture has main income of most Sungai Alang villagers who live along side the Riam Kanan River. Cage aquaculture is intensive fish farming systems with artificial feeding. The uneaten feed and excretion from cage aquaculture will affect the feasibility of water quality for cultivated fish. To evaluate the impact of the cage aquaculture, the study has been done on water quality profile around aquaculture activities in the Sungai Alang village. Water sampling locations set by purposive sampling: one site on the upstream (~c50 m from the fish cage), two site in the cage aquaculture area and one site at down stream (~c 50 m from the fish cage). Water sampling and measurement of water quality include: temperature, pH, DO, BOD5, COD, total �P, NH3-N, NO3-N was held from May 15, 2011 till September 4, 2011 with 15 days interval of observation. Cage aquaculture activities on Riam Kanan River which conducted by Sungai Alang society has caused the decreased levels of DO in the downstream and cage aquaculture area. At the level of technology and scale that are developed today, cage aquaculture activities still has not shown a critical level in water quality."

" Situ (shallow lake) Cibuntu which is located on LIPI Cibinong Complex facing superficiality caused by sedimentation which was dominated by highly TSS (Total Suspended Solids) load. Local people utilize this shallow lake for fisheries activity. In order to maintain the sustainability of its utilization, it was needed a management concept development based on its aquatics physical characteristics. The objective of this research was to determine the each relation of observed water quality parameter. Monitoring on aquatics physical parameter such as water temperature, turbidity, TSS and water conductivity conducted on March, May, July, October, December 2008 and February 2009 at seven stations. The condition of Situ Cibuntu was characterized by the average of its water temperature 27.64~�C, water turbidity 15.97 NTU, TSS 53.60 mg/L and water conductivity 0.119 ~kS/cm which exhibited this shallow lake waters appropriate for fish culturing water quality standards. The result show that water turbidity was had positive correlation to TSS (r=0.996) which indicated that higher TSS causing water turbidity increased accordingly."

"At present, ecosystem function in lake ulak lia can be found as i.e. : recreation area, fisheries and retention basin of music river.Meanwhile , the basis data of these ecosystem function was limited and difficult to assess so far...."

"Danau Limboto di Provinsi Gorontalo merupakan aset ekologis aset media produksi perikanan."

"Penyediaan air bersih untuk konsumsi masyarakat umum telah menjadi permasalahan yang sangat mendesak bagi pemerintah, khususnya Pemerintah DKI Jakarta Air permukaan merupakan sumber air bersih yang harus dimanfaatkan secara optimal. Pencemaran yang terjadi pada air permukaan mengharuskan dilakukannya proses pengolahan air, dengan salah satu metodenya adalah filtrasi Penelitian filtrasi menggunakan karbon aktif dilakukan dengan sistem aliran vertikal ke atas, sedangkan sampel air permukaan yang digunakan adalah air danau Universitas Indonesia. Penelitian dilakukan untuk melihat kemampuan karbon aktif menurunkan kandungan padatan tersuspensi pada sampel, serta melakukan perbandingan dengan menggunakan variasi tinggi unggun karbon aktif yaitu 20 cm, 15 cm, dan 18 cm. Sebelum digunakan, karbon aktif terlebih dahulu melalui proses preparasi. Sampel yang diambil sesuai dngan metodologi penelitian, kemudian dikarakterisasi dengan menggunakan TSS. Laju alir influent diatur pada 0,7 ml/s.Hasil yang didapat dari penelitian menunjukkan alat Eltrasi dapat menurunkan kandungan padatan tersuspensi sampel air permukaan sampai di bawah 10 mg/L dengan air yang lebih jernih. Pada variasi tinggi unggun karbon aktif dilihat bahwa karbon aktif yang menggunakan influent dengan kandungan padatan tersuspensi yang lebih besar akan memiliki persen padatari tersuspensi yang lebih besar, berhubungan dengan jumlah padatan tersuspensi yang dapat diadsorpsi dan ditahan oleh filter karbon aktif. Dari hasil penelitian, filter 15 cm memiliki persen padatan tersuspensi tereduksi akhir yang paling besar, yaitu 76,67% dengan injiuenr 30 mg/L."