Lake Tondano Research Articles

Studi Parameter Fisika Kimia Air pada Areal Budidaya Ikan di Danau Tondano, Desa Paleloan, Kabupaten Minahasa

The purpose of this research was to analyze the physical and chemical parameters of waters (temperature, turbidity, pH, dissolved oxygen, nitrate, phosphate, ammonia and BOD) around net cage culture area at Peleloan Village, Minahasa Regency and to determine the suitable culture site supporting optimal growth of fish. water quality was measured at three sites. Temperature, turbidity, and pH were measured in situ while dissolved oxygen, nitrate, phosphate, ammonia and BOD were analised in laboratorium. Research results showed water temperature at all observation sites ranged from 25.5-28.2 0C, turbidity 2.02-3.15 m, pH 6.8 – 8.2, DO 7.41-7.77 mg/L, nitrate 0.3-0.5 mg/L, phosphate 0.00-0.4 mg/L, ammonia 0.13-0.77 mg/L. Based on water quality standard criteria stated in PP No. 82, 2001, temperature, turbidity, pH, DO and nitrate at fish culture area were suitable for floating and stick net cage cultures but ammonia at all sites of observation, phosphate at site I at 0.5 m from the bottom and BOD at site III at 0.5 m from the bottom were exceeding the standard criteria. Keywords: water physical and chemical Parameters, floating net cage, Lake Tondano, Paleloan Village

Analisis kualitas fisika kimia air di areal budidaya ikan Danau Tondano Provinsi Sulawesi Utara

ABSTRACT The objective of this research was to analyse the water physical-chemical qualities at aquaculture area in Lake Tondano North Sulawesi. Water quality was measured in situ and in laboratotium. In situ measurement included temperature, pH, and turbidity, while in laboratory, water quality measured included dissolved oxygen, nitrogen, phosphate. It was found that water temperature ranged from 25 - 27 o C, turbidity 0.20 - 4,0 m, and dissolved oxygen 5 – 9 mg/L, Nitrogen 0,0334 - 0,0697 mg/ L, phosphate 0 - 0,0219 mg/ L. It was concluded that water quality around Paleloan Village was appropriate for aquaculture activity. Keywords: water quality, aquaculture, Paleloan Village

KUALITAS AIR PADA LOKASI BUDIDAYA IKAN DI PERAIRAN DESA ERIS, DANAU TONDANO, KABUPATEN MINAHASA

Eris Society in the village of utilizing the waters of Lake Tondano as a place to fish cultivation in floating net system and step on floating net karamba system. Karamba unit developments and floating net cages in the area of ​​cultivation step on the less controllable negative impact on the aquatic environment such as pollution of water quality. For this study aims to measure the quality parameters including pH, temperature, brightness and analyzed water quality parameters including turbidity, dissolved oxygen, ammonia and phosphate so that the water quality conditions in the Village of Lake Tondano District Eris Eris known. From the results obtained by the temperature at a depth of 0.5 meters from surface water ranged from 25.3 to 28.3 º C, at a depth of 0.5 meters from the lake bottom ranged from 24.7 to 28 º C, the brightness ranges from 182-325 cm, turbidity ranges from 7 - 16 NTU, the pH at a depth of 0.5 meters from the water surface ranged from 6.89 to 8.09, at a depth of 0.5 meters from the lake bottom ranged from 6.93 to 8.03, dissolved oxygen ranged from 7.10 to 7.52 mg / L, ammonia ranging from 0.03 to 0.14 mg / L, and phosphate ranged from 0.02 to 0.12 mg / L. Temperature, brightness, pH, dissolved oxygen and phosphate at the sites are still in good condition that is still in accordance with the water quality standard. For turbidity and ammonia has passed the threshold water quality standard. This is presumably due to domestic wastewater effluent from surrounding communities, causing decomposition which affects the water quality conditions. However the waters in the village of Eris can be used for aquaculture. This is evidenced by the persistent cultivation of fish in the Village District Eris Eris.

STUDI FITOPLANKTON DI DANAU TONDANO PROVINSI SULAWESI UTARA

This research was conducted in Tondano Lake North Sulawesi for 3 month from June to August 2007. The research was aimed to identify species abundance of phytoplankton. Phytoplankton were collected by using a 40 μm large plankton net. Results showed that phytoplankton consisted of 32 genera. It also indicated that the highest individual abundance was shown by Fragillaria (2903 individuals), followed by Microspora (2349 individuals), Closterium ( 984 individuals), Zynema (803 individuals), Melosira (770 individuals), and Anabaena (693 individuals) respectively with monthly sampling the highest abundance was on August (4227 individuals), followed by June (3516 individuals), and July (3493 individuals).

Gerakan struktur dan kaitannya dengan faktor kendali tektonik, berdasarkan analisis stratigrafi; Studi kasus geologi kuarter terhadap fase perkembangan Danau Tondano purba sepanjang Remboken - Kakas, Kec. Remboken dan Kec. Kakas, Kab. Tomohon, Sulawesi Ut

Http://dx.doi.org/10.17014/ijog.vol2no3.20075Studies of stratigraphy on Quaternary deposits in the southwest region of Lake Tondano, Tomohon Regency, South Sulawesi, revealed six facies of deposition environments. These facies consist of Tondano tuff, young volcanic eruption, lake, sand lake, tidal lake, and swamp deposits. Based on the correlation of the lateral and vertical variation of the Quaternary deposits, three unit of the depositional facies were recognized (UFP I-III). Each of the depositional facies unit is characterized by variation of the depositional environment changes which were controlled by tectonics, and was followed by the activity of Sonder main fault. The Sonder main fault activity, which controlled the depositional environment changes was recorded as an UFP. Probably, the character of this stratigraphy could be called as cyclo-tectonostratigraphy. The study was based on analyses of sedimentology and stratigraphy of six borehole information obtained along the E-NW traverse which is approximately parallel to the shorelines of the southwestern part of Lake Tondano. The penetration of the borehead varied from 1.20 to 8.7 m.

FUNGSI STRATEGIS DANAU TONDANO, PERUBAHAN EKOSISTEM DAN MASALAH YANG TERJADI

Tondano is a natural and biggest lake in North Sulawesi which some strategic functions i.e for irrigation, source of drinking water, hydropower, freshwater culture, tourisms, overflow control. Wide of Tondano Lake is about 46 – 51 km2. There are 35 streams as inlet and one outlet only is Tondano Stream. Tondano Lake has some problems caused by many activities both in downstream area or around of the lake. People’s activities such as land clearing for plantation in downstream area, freshwater cultureand daily people’s activities around of the lake had been organic material contribution in the lake waters. It has caused of water hyacinth booming (Eichornia crassipes (Malt) (Soms), erosion and sedimentation. Nowadays water hyacinth has been covered about 20% of Tondano Lake’s wide. Besides reduce of waters quality, water hyacinth booming has been made problems for hydropower and traffic in lake waters to the outlet. Because of that problems, Tondano Lake needs concern for intensif management.Key Words : strategic functions, ecosystem, erosion, sedimentation, water hyacinth.

Effects of gypsum addition on sedimentation characteristics of Tondano Lake clay, Indonesia

Effects of gypsum addition on sedimentation characteristics of Tondano Lake clay, Indonesia

The geochemical characteristics of sediment in Tondano Lake, Indonesia: heavy metals and organic matter contents, and grain size distribution

Sediment quality of Tondano Lake, Indonesia has been investigated through measuring the geochemical characteristics such as the content of heavy metals, organic matter and grain size distribution; and also the relationship between heavy metals and organic matter, and between heavy metals and grain size distribution. These could be used as preliminary data for the purpose of evaluating lake condition as a part of freshwater ecosystem. The Tondano sediment had contained some heavy metals such as Cr, Cu, Hg, and Zn; where Cr and Zn, both less than the Sediment Quality Guideline (SQG), but Cu and Hg were well within the SQG. Organic matter content was highest at the northern outlet area, with the lowest amount at the southern inlet area. Grain size distribution was mostly dominated by sandy-loam clay (the highest content was at central lake). This was a result of intensive agricultural activities surrounding the lake, which brought sand grain via rivers from all areas to the central lake. The heavy metal contents were not found to be correlated with the organic matter, nor the grain size distribution (clay content).

PEMBERIAN PELLET ECENG GONDOK (Echhornia crassipes) TERHADAP PERTUMBUHAN IKAN NILA MERAH (Oreochoromis sp) DI JARING TANCAP

The research of on the growth of red nila fish measuring 10-12 cm in length and 27-32 g in weight feed with pellet containy different compocition of eceng gondok leaf powder has been carried out in Tondano lake, Eris village, Eris district, Minahasa Agency. The arm of this rescearch is to find out with compotition (10%, 20%, 30%) of pellet from eceng gondok lef that have different composition (10%, 20%, 30%) in pellet give the best relative growth, effisiency value and nutrient convertion value in comparison with commercial pellets. The result showed that pellet contaning 10% eceng gondok powder hed the nigest relative growth (195.4%, efficiency value (61.65) and nutrient convertion value (1.6). Commercial pellet used as control hower is still relatively better compare with all experimental pellets containing defferent competition of eceng gondok in terms of relative growth, effisiency value and nutrient convertion value. Keywords: Red nila (Oreochormis sp), Eceng gondok pellets (Echhornia crassipes), Set net (jaring tancap)

Palaeoenvironmental developments in the Lake Tondano area (N. Sulawesi, Indonesia) since 33,000 yr B.P.

Geo(morpho)logical, sedimentological and ecological developments in the Lake Tondano area since ±33,000 yr B.P., and limnological changes in the moderately-sized lake situated at 680 m asl in the northern part of Sulawesi, Indonesia are discussed. First, the environmental setting of the lake is presented. Study of the regional distribution of lacustrine sediments, and a detailed analysis of their sedimentary facies (texture, organic matter content) suggest major changes in size and depth of the lake and in past sedimentation. Insight into the long-term development of the lake (sedimentation processes) is highly relevant for sustainable use of the present lake. Analysis of diatom assemblages provides further detail of the changing aquatic settings of the lake; lake levels rise quickly around 33,000 and 12,000 yr B.P., fall dramatically between ±30,000 and 13,000 yr B.P. and are lowered gradually since approximately 6000 yr B.P., following Early Holocene high lake levels. Drainage of the lake is affected by both volcanic depositional events and regional climatic events. Palynological analysis is indicative of local palaeoecological settings in the lake area and regional climatic change; a distinct, Late Pleistocene phase, with lower precipitation and lowered mean temperatures is inferred. Furthermore, progressive deforestation of the Tondano uplands is evident, as well as diffuse anthropogenic/volcanic vegetation disturbance from the early Mid Holocene onwards. Information from sedimentary facies, diatom assemblages and local palaeoecology (pollen) are integrated to reconstruct palaeoenvironmental settings and processes in the lake area. This record of environmental change as well as the pollen-based record of regional vegetation and climate change corroborates other palaeoenvironmental data derived from the few terrestrial sites in the region. The data attribute a greater magnitude of temperature and precipitation change in the region than is commonly deduced in studies based on marine faunal and sedimentary records. The Lake Tondano sedimentary record is highly suitable for further analysis aimed at determining the exact timing and amplitudes of environmental change in the SE Asian equatorial region.

ECONOMIC ASSESSMENT OF SOIL CONSERVATION DEMONSTRATION PLOTS IN TONDANO WATERSHED, NORTH SULAWESI, INDONESIA

The objective of this study was to assess the economics of soil conservation demonstration plots (demplots) in Tondano Watershed, North Sulawesi, Indonesia, using a benefit-cost framework. Soil conservation demplots affect farm output, Lake Tondano, hydroelectric production, water supply, fishing, Manado Harbor, riverbank inhabitants, and Bunaken Marine Park. Using a 25-year project life, discounting at 6 percent, the annualized net return of farmland with soil conservation demplots was Rp472,800 (U.S. $220) per hectare, whereas the annualized net return of farmland without soil conservation was Rp317,600 (U.S. $148) per hectare. The off-site benefit of 80, 10-hectare soil conservation demplots was estimated at Rp2,086 million (U.S. $1 million) annually, based on a conservative assumption that soil conservation in all critical areas in Tondano Watershed would reduce off-site/downstream damages by 10 percent. Adoption rate of soil conservation practices is low. Farmers may be unable financially to integrat...

DISTRIBUSI SPASIO -TEMPORAL NITROGEN DI DAERAH TANGKAPAN AIR DANAU TONDANO PROVINSI SULAWESI UTARA

The spatio temporal distribution of nitrogen in catchment area of Lake Tondano wasimportant to investigate because agricultural residue comes from the catchment potentiallydecreased water quality in Lake Tondano. The purpose of this study was to examine thedistribution of nitrogen spatially and temporally in the catchment area of Lake Tondano.The study was conducted in the field and laboratory. Water quality sampling conducted byusing composite sampling on the rivers, lake Tondano and outlet of irrigation channels.The data collected was the total nitrogen, nitrate, ammonia in 2001, 2008 and 2014. Datawere analyzed using Graph Method and Spatial Analysis. The results showed that the distribution of total nitrogen that has a high concentrationfound in the outlet streams and irrigation canals outlet. High nitrate accumulates in theoutlet of Lake Tondano. Nitrate concentration can be divided into 9 (nine) classes, namelyconcentration of 0.100 to 0.211 mg / l; 0.211 to 0.322 mg / l; 0.322 to 0.433 mg / l; 0.433 to0.544 mg / l; From 0.544 to 0.655 mg / l; From 0.655 to 0.766 mg / l; 0.766 to 0.877 mg / l;0.877 to 0.988 mg / l; and 0,988- 1,100 mg / l. Ammonia, spatially spread evenly on thesurface of Lake Tondano. Ammonia concentration can be divided into 9 (nine) class is aclass that has a concentration of 0.000 to 0.064 mg / l; From 0.064 to 0.129 mg / l; 0.129 to0.193 mg / l; From 0.193 to 0.258 mg / l; 0.258 to 0.322 mg / l; 0.322 to 0.387 mg / l; From0.387 to 0.451 mg / l; 0.451 to 0.516 mg / l; and from 0.516 to 0.580 mg / l. Concentrationsof nitrate and ammonia fluctuated from year to year of observation. This was influenced byfertilization in rice fields.