Water Quality Conditions and Trophic Status of Lake Toba, North Sumatra,Indonesia: Implications for Lake Management
Abstract
Lake Toba, the largest lake in Indonesia and Southeast Asia, is a multifunctional ecosystem supporting fisheries, tourism, transportation, domestic water supply, hydropower generation, agriculture, and surrounding human settlements. This study comprehensively evaluated the spatial and temporal variations in water quality and trophic status using integrated water quality
indices and trophic state indicators. Surface water samples were collected from 21 stations during the dry and rainy seasons of 2024. Water quality was assessed using the Pollution Index (PI) and the Canadian Council of Ministers of the Environment Water Quality Index (CCME-WQI), and trophic status was determined using the Trophic State Index (TSI) and TSIlamp. PI results classified Lake Toba as lightly polluted under Class I criteria (3.53 ± 0.82 dry season; 3.44 ± 0.81 rainy season) and good to lightly polluted under Class II standards (1.72 ± 0.59 dry; 1.74 ± 0.78 rainy season). Trophic conditions ranged from oligotrophic to eutrophic across the stations, with
an overall mesotrophic status. The mean trophic index increased from 42.37 ± 3.43 in the dry season to 47.03 ± 3.98 in the rainy season, indicating a gradual increase in ecosystem productivity. Although the overall water quality remains suitable for Class II uses, the upward trophic trend signals increasing nutrient pressure. These findings underscore the need for proactive management, particularly the regulation of floating net-cage aquaculture expansion, to mitigate organic loading and prevent progressive eutrophication in Lake Toba.
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References
1. de Silva, S.L.; Mucek, A.E.; Gregg, P.M.; Pratomo, I. Resurgent Toba—Field, Chronologic, and Model Constraints on Time Scales and Mechanisms of Resurgence at Large Calderas. Frontiers in Earth Sciences 2015, 3, 1–17, doi:10.3389/FEART.2015.00025/ABSTRACT.
2. Chesner, C.A. The Toba Caldera Complex. Quaternary International 2012, 258, 5–18, doi:10.1016/j.quaint.2011.09.025.
3. Lukman; Ridwansyah, I. Kajian Kondisi Morfometri Dan Beberapa Parameter Stratifikasi Perairan Danau Toba. Limnotek : perairan darat tropis di Indonesia 2010, 17, 158–170.
4. Klanten, R.; Allsop, L. The UNESCO Global Geoparks; Die Gestalten Verlag: Berlin, 2024;
5. Lumbanraja, V.; Nasution, N.F. Preserving the Lake Toba Ecosystem: Strategic Planning to Mitigate Red Devil Fish Invasion. IOP Conf. Ser. Earth Environ. Sci. 2024, 1352, 012057, doi:10.1088/1755-1315/1352/1/012057.
6. Hutajulu, C.P.; Harahap, R.H. The Impact of Floating Craft Cultivation on the Ecosystem of Lake Toba. AQUACOASTMARINE: Journal of Aquatic and Fisheries Sciences 2023, 2, 8–15, doi:10.32734/jafs.v2i1.10126.
7. Presidential Regulation. Peraturan Presiden Nomor 81 Tahun 2014 tentang Rencana Tata Ruang Kawasan Danau Toba dan sekitarnya; Secretariat of the Republic of Indonesia: Jakarta, ID, 2014;
8. Presidential Regulation. Peraturan Presiden Nomor 89 Tahun 2024 Rencana Induk Destinasi Pariwisata Nasional Danau Toba Tahun 2024 - 2044; Secretariat of the Republic of Indonesia: Jakarta, ID, 2024;
9. Lubis, R.E.; Irawaty, M.H.; Ibrohim; Indriwati, S.E. Identification and Diversity of Organisms in the Lake Toba Area. Jurnal Pendidikan IPA Indonesia 2019, 8, 361–370, doi:10.15294/JPII.V8I3.19043.
10. Saragih, F.S.; Djamil, H.; Juanda, J.; Mubarak, A.S.; Hasan, V.; Sihombing, A.; Satyantini, W.H. Nutrient Concentration, Water Brightness, Chlorophyll-a, and Phytoplankton Abundance as Indicators for Determining the Trophic Status of Lake Toba, North Sumatera - Indonesia. Journal of Aquaculture and Fish Health 2024, 13, 366–374, doi:10.20473/JAFH.V13I3.57981.
11. Intiar, S.; Siarit, E.; Wijaya, V.; Adityaji, R.; Oktavio, A. Sport Tourism As Tourism Development In The Lake Toba Area In The Aquabike Jetski World Championship 2023. INNOVATIVE: Journal Of Social Science Research 2023, 4, 1026–1036.
12. Wiranti, Y.; Nasution, Y.R. Sentiment Analysis of Reviews of Tourist Attractions in the Lake Toba Area Using the Naïve Bayes Method. Journal of Computer Networks, Architecture and High Performance Computing 2024, 6, 1253–1264.
13. Imamulhadi; Kurniati, N. Critical Review of Indonesian Government Legal Policies on The Conversion of Protected Forests and Communal Lands of The Indigenous Batak People around Lake Toba. Padjadjaran Jurnal Ilmu Hukum 2019, 6, 446–465, doi:10.22304/PJIH.V6N3.A2.
14. Napitu, U.; Corry, C.; Napitu, H.; Ambarita, R.; Sihola, B.; Panjaitan, F. Adaptation of the Toba Batak Community in Conservation of the Lake Toba Environment. JPPI (Jurnal Penelitian Pendidikan Indonesia) 2022, 8, 888–896, doi:10.29210/020221691.
15. Mastin, L.G.; Van Eaton, A.R.; Lowenstern, J.B. Modeling Ash Fall Distribution from a Yellowstone Supereruption. Geochemistry, Geophysics, Geosystems 2014, 15, 3459–3475, doi:10.1002/2014GC005469.
16. Lukman; Hidayat, H.; Subehi, L.; Dina, R.; Mayasari, N.; Melati, I.; Sudriani, Y. Loads of Pollution to Lake Toba and Their Impacts. Int. J. Adv. Sci. Eng. Inf. Technol. 2021, 11, 930–936, doi:10.18517/ijaseit.11.3.12733.
17. Lukman, L.; Hidayat; Subehi, L.; Dina, R.; Mayasari, N.; Melati, I.; Sudriani, Y.; Ardianto, D. Pollution Loads and Its Impact on Lake Toba. IOP Conf. Ser. Earth Environ. Sci. 2019, 299, 012051, doi:10.1088/1755-1315/299/1/012051.
18. Barus, T.A.; Wahyuningsih, H.; Hartanto, A. Water Quality and Trophic Status of Lake Toba, North Sumatra, Indonesia. Hydrobiological Journal 2022, 58, 34–43, doi:10.1615/HydrobJ.v58.i2.30.
19. Hastuti, Y.P.; Nirmala, K.; Hutagaol, M.P.; Tanjung, D.; Kriswantriyono, A.; Nurussalam, W.; Wulandari, Y.P.; Fatma, Y.S. Analysis of Main Components of Lake Toba’s Water Quality in Different Seasons. Adv. Oceanogr. Limnol. 2024, 15, 11726, doi:10.4081/aiol.2024.11726.
20. Purba, I.R.; Nurhayati, N. Water Quality Of Lake Toba By Space And Time Based On Environmental Physics, Chemical Factors And Community Phytoplankton. Eduvest - Journal of Universal Studies 2022, 2, 2379–2396, doi:10.59188/EDUVEST.V2I11.609.
21. Meteorology, Climatology, and Geophysics Agency. Prediksi Musim Hujan 2024/2025 Di Indonesia; Jakarta, 2024;
22. APHA Standard Methods for The Examination of Water and Wastewater; Rice, E.W., Baird, R.B., Eaton, A.D., Eds.; 23rd ed.; American Public Health Association, American Water Works Association, and Water Environment Federation: Washington, D.C., 2017;
23. Government of the Republic of Indonesia. Peraturan Pemerintah Nomor 22 Tahun 2021 tentang Penyelenggaraan Perlindungan dan Pengelolaan Lingkungan Hidup; Government of the Republic of Indonesia: Jakarta, ID, 2021
24. FAO Guidelines for Drinking-Water Quality: Fourth Edition Incorporating the First Addendum; Fourth.; World Health Organization: Geneva, 2017;
25. Ministry of Environtment. Keputusan Menteri Lingkungan Hidup Nomor 115 Tahun 2003 Tentang Pedoman Penentuan Status Mutu Air; Ministry of Environtment Republic of Indonesia: Jakarta, ID, 2003;
26. Ministry of Environment and Forestry. Peraturan Menteri Lingkungan Hidup Dan Kehutanan Nomor 27 Tahun 2021 tentang Indeks Kualitas Lingkungan Hidup; Ministry of Environment and Forestry Republic of Indonesia: Jakarta, ID, 2021;
27. CCME Canadian Water Quality Guidelines for the Protection of Aquatic Life: CCME Water Quality Index User’s Manual 2017 Update; Winnipeg, 2017;
28. Uddin, M.G.; Nash, S.; Olbert, A.I. A Review of Water Quality Index Models and Their Use for Assessing Surface Water Quality. Ecol. Indic. 2021, 122, 107218, doi:10.1016/J.ECOLIND.2020.107218.
29. Romdania, yuda; Herison, A.; Susilo, G.E.; Novilyansa, E. Kajian Penggunaan Metode IP, STORET, Dan CCME WQI Dalam Menentukan Status Kualitas Air. Jurnal SPATIAL Wahana Komunikasi dan Informasi Geografi 2018, 18, 1–13, doi:10.21009/spatial.181.05.
30. Carlson, R.E. A Trophic State Index for Lakes. Limnol. Oceanogr. 1977, 22, 361–369, doi:10.4319/lo.1977.22.2.0361.
31. Bucci, M.M.H.S.; Delgado, F.E. da F.; de Oliveira, L.F.C. Water Quality and Trophic State of a Tropical Urban Reservoir for Drinking Water Supply (Juiz de Fora, Brazil). Lake Reserv. Manag. 2015, 31, 134–144, doi:10.1080/10402381.2015.1029151.
32. Thorndahl, S.; Nielsen, J.M.; Rasmussen, M.R. Model-Based Prediction of Bathing Water Quality in a Lake Polluted by Fecal Coliform Bacteria from Combined Sewer Overflows. J. Environ. Manage. 2024, 349, 119483, doi:10.1016/j.jenvman.2023.119483.
33. Muhtadi, A.; Yulianda, F.; Boer, M.; Krisanti, M.; Riani, E.; Leidonald, R.; Hasani, Q.; Cordova, M.R. Assessment of Pollution Status of Tropical Coastal Lakes Using Modified Water Quality Index (WQI) Based on Physio-Chemical Parameters. AACL Bioflux 2023, 16, 356–370.
34. Nastuti, R.; Soeprobowati, T.R.; Utomo, S. Water Quality of Maninjau Lake, West Sumatera Province Based on Pollution and STORET Indices.; AIP Conf. Proc, 2023; p. 030002.
35. Syandri, H.; Azrita, A.; Mardiah, A. Water Quality Status and Pollution Waste Load from Floating Net Cages at Maninjau Lake, West Sumatera Indonesia. IOP Conf. Ser. Earth Environ. Sci. 2020, 430, 012031, doi:10.1088/1755-1315/430/1/012031.
36. Sulawesty, F.; Triyanto; Haryani, G.S.; Samir, O.; Hidayat; Wibowo, H.; Lukman; Ali, F.; Setiawan, F.A.; Riyanto, M.; et al. Assessment of Water Quality in the Poso Watershed Based on the Pollution Index and Carlson Trophic Status Index. In Proceedings of the 2nd International Conference and Scientific Meeting of the Indonesian Limnology Society (SMILS II) and the 4th International Conference on Tropical Limnology (TROPLIMNO IV); IOP Conference Series: Earth and Environmental Science: Bogor, December 1 2024; p. 012008.
37. Sulawesty, F.; Triyanto; Haryani, G.; Lukman; Samir, O.; Ali, F.; Nafisyah, E. Trophic Status of Waters in Poso Watershed, Central Sulawesi. In Proceedings of the 2nd International Seminar on Natural Resources and Environmental Management (2nd ISeNREM 2021); IOP Conference Series: Earth and Environmental Science: Bogor, January 1 2022; p. 012039.
38. Ash Siddiq, R.H.B. Analysis of Water Pollution Status in Singkarak Lake West Sumatra Province, Indonesia. Solid State Technology 2020, 63, 3202–3207.
39. Piranti, A.S.; Rahayu, D.R.U.S.; Waluyo, G. Evaluasi Status Mutu Air Danau Rawapening. Jurnal Pengelolaan Sumberdaya Alam dan Lingkungan (Journal of Natural Resources and Environmental Management) 2018, 8, 151–160, doi:10.29244/jpsl.8.2.151-160.
40. Tanjung, R.H.R.; Indrayani, E.; Agamawan, L.P.I.; Hamuna, B. Water Quality Assessment to Determine the Trophic State and Suitability of Lake Sentani (Indonesia) for Various Utilisation Purposes. Water Cycle 2024, 5, 99–108, doi:10.1016/j.watcyc.2024.02.006.
41. Komala, P.S.; Soeprobowati, T.R.; Takarina, N.D.; Subehi, L.; Wojewódka-Przybył, M.; Primasari, B.; Edwin, T.; Ridwan, R.; Rahmadiningsih, E.; Mardatillah, R. Spatio-Temporal Changes of Water Quality Based on Water Quality Index Method in Tropical Lake of Indonesia. Water Air Soil Pollut. 2023, 234, 594, doi:10.1007/s11270-023-06599-9.
42. Fukushima, T.; Setiawan, F.; Subehi, L.; Jiang, D.; Matsushita, B. Water Temperature and Some Water Quality in Lake Toba, a Tropical Volcanic Lake. Limnology (Tokyo). 2023, 24, 61–69, doi:10.1007/s10201-022-00703-4.
43. Nomosatryo, S.; Lukman Klasifikasi Trofik Danau Toba, Sumatera Utara. Limnotek 2012, 19, 13–21.
44. Governor of North Sumatra. Keputusan Gubernur Sumatera Utara Nomor 188.44/209/KPTS/2017 tentang Status Trofik Danau Toba; Pemerintah Provinsi Sumatera Utara: Medan, 2017;
45. Governor of North Sumatra. Surat Keputusan Gubernur Sumatera Utara Nomor 188.44/213/KPTS/2017 tentang Daya Dukung Dan Daya Tampung Danau Toba; Pemerintah Provinsi Sumatera Utara: Medan, 2017;
46. Kronvang, B.; Wendland, F.; Kovar, K.; Fraters, D. Land Use and Water Quality. Water (Basel). 2020, 12, 2412, doi:10.3390/w12092412.
47. Ogundairo, E.S.; Awokola, O.S.; Badejo, A.A.; Awomeso, J.A.; Folarin, G.M.; Alao, A.O.; Folarin, I.A.; Taiwo, A.M. Assessment of Impacts of Land Use, Land Cover on Water Quality in Eleyele Catchment Area, Ibadan, South-Western Nigeria. Discover Water 2025, 5, 73, doi:10.1007/s43832-025-00275-1.
48. Szymańska - Walkiewicz, M.; Matela, M.; Obolewski, K. Patterns of Effects of Land-Use Structure on Lake Water Quality in Coastal Lake Catchments of the Southern Baltic Sea. Ecohydrology & Hydrobiology 2024, 24, 447–458, doi:10.1016/j.ecohyd.2023.07.004.
49. Wei, Z.; Yu, Y.; Yi, Y. Spatial Distribution of Nutrient Loads and Thresholds in Large Shallow Lakes: The Case of Chaohu Lake, China. J. Hydrol. (Amst). 2022, 613, 128466, doi:10.1016/j.jhydrol.2022.128466.
50. Zhou, Q.; Chen, H.; Cheng, B.; Cheng, Y.; Guo, B. A Study of the Effect of Lake Shape on Hydrodynamics and Eutrophication. Sustainability 2025, 17, 1720, doi:10.3390/su17041720.
51. Huang, J.; Xu, Q.; Xi, B.; Wang, X.; Jia, K.; Huo, S.; Su, J.; Zhang, T.; Li, C. Effects of Lake-Basin Morphological and Hydrological Characteristics on the Eutrophication of Shallow Lakes in Eastern China. J. Great Lakes Res. 2014, 40, 666–674, doi:10.1016/j.jglr.2014.04.016.
52. Pakoksung, K.; Inseeyong, N.; Chawaloesphonsiya, N.; Punyapalakul, P.; Chaiwiwatworakul, P.; Xu, M.; Chuenchum, P. Seasonal Dynamics of Water Quality in Response to Land Use Changes in the Chi and Mun River Basins Thailand. Sci. Rep. 2025, 15, 7101, doi:10.1038/s41598-025-91820-4.
53. Li, K.; Wang, L.; Li, Z.; Xie, Y.; Wang, X.; Fang, Q. Exploring the Spatial-Seasonal Dynamics of Water Quality, Submerged Aquatic Plants and Their Influencing Factors in Different Areas of a Lake. Water (Basel). 2017, 9, 707, doi:10.3390/w9090707.
54. Lew, S.; Glińska-Lewczuk, K.; Burandt, P.; Grzybowski, M.; Obolewski, K. Fecal Bacteria in Coastal Lakes: An Anthropogenic Contamination or Natural Element of Microbial Diversity? Ecol. Indic. 2023, 152, 110370, doi:10.1016/j.ecolind.2023.110370.
55. Abdulaziz, A.; Sathyendranath, S.; Vijayakumar, S.K.; Menon, N.; George, G.; Kulk, G.; Raj, D.; Krishna, K.; Rajamohananpillai, R.; Tharakan, B.; et al. The Distribution of Fecal Contamination in an Urbanized Tropical Lake and Incidence of Acute Diarrheal Disease. ACS ES&T Water 2023, 3, 1561–1573, doi:10.1021/acsestwater.2c00255.
56. Froelich, K.L.; Reimink, R.L.; Welch, C.P.; Ransom, J.; Otto, S.J.G.; Hanington, P.C. Assessing Fecal Pollution Source in a Northern Michigan Lake Using QPCR and a Community-Based Monitoring Framework. PLoS One 2025, 20, e0331494, doi:10.1371/journal.pone.0331494.
57. Kim, B.-K.; Kim, D.H.; Hwang, J.H. Impact of Water Residence Time and Stratification on Water Quality Improvement of an Artificial Brackish Waterway. J. Hydrol. Reg. Stud. 2025, 57, 102091, doi:10.1016/j.ejrh.2024.102091.
58. Auger, G.A.R.; Kelly, M.R.; Moriarty, V.W.; Rose, K.C.; Kolar, H.R. Understanding Lake Residence Time Across Spatial and Temporal Scales: A Modeling Analysis of Lake George, New York USA. Water Resour. Res. 2024, 60, doi:10.1029/2022WR034168.
59. Cui, K.; Xing, B.; Li, Y.; Zhu, R.; Gao, X.; Cheng, X.; Sun, D.; Huang, K. Source Identification and Control of Eutrophication in Large Shallow Freshwater Lakes: A Case Study of Lake Taihu. Water (Basel). 2025, 17, 2370, doi:10.3390/w17162370.
60. Pérez-Ruzafa, A.; Campillo, S.; Fernández-Palacios, J.M.; García-Lacunza, A.; García-Oliva, M.; Ibañez, H.; Navarro-Martínez, P.C.; Pérez-Marcos, M.; Pérez-Ruzafa, I.M.; Quispe-Becerra, J.I.; et al. Long-Term Dynamic in Nutrients, Chlorophyll a, and Water Quality Parameters in a Coastal Lagoon During a Process of Eutrophication for Decades, a Sudden Break and a Relatively Rapid Recovery. Front. Mar. Sci. 2019, 6, 26, doi:10.3389/fmars.2019.00026.
61. Jaelani, L.M.; Pangestu, M.A. Monitoring of Lake Water Quality Through Streamlit Web Application (Case Study: Lake Matano And Lake Towuti, South Sulawesi). Geoid 2023, 18, 293–301, doi:10.12962/j24423998.v18i2.14396.
62. Noor, S.Y. Trophic Status of Limboto Lake in Gorontalo Province. IOP Conf. Ser. Mater. Sci. Eng. 2019, 567, 012029, doi:10.1088/1757-899X/567/1/012029.
63. Kaban, S.; Ditya, Y.C.; Makmur, S.; Fatah, K.; Wulandari, T.N.M.; Dwirastina, M.; Makri, M.; Samuel, S. Water Quality and Trophic Status to Estimate Fish Production Potential for Sustainable Fisheries in Lake Poso, Central Sulawesi. Pol. J. Environ. Stud. 2023, 32, 4083–4093, doi:10.15244/pjoes/168102.
64. Hidayah, T. The Trophic Status and Fish Potential Yield of Ayamaru Lake in West Papua, Indonesia. Sriwijaya Journal of Environment 2021, 6, 99–106, doi:10.22135/sje.2021.6.3.99-106.
65. Sutrisno, A.J.; Handoko, M. Spatial Distribution of Water Quality Classes of Rawa Pening Lake. In Proceedings of the The 7th International Symposium of Sustainable Landscape Development (ISSLD); IOP Conference Series: Earth and Environmental Science: Bogor, August 1 2024; p. 012013.
66. Astuti, Y.; Ain, C.; Rahman, A.; Jati, O.E.; Prakoso, K. Profil Lingkungan Dan Kesuburan Perairan Di Danau Rawa Pening, Kabupaten Semarang, Jawa Tengah. Jurnal Akuatiklestari 2024, 8, 85–90, doi:10.31629/akuatiklestari.v8i1.6934.
67. Prasetyo, S.; Soeprobowati, T.R.; Tirtadanu, T.; Purnomo, A.; Hartati, S.; Chodrijah, U.; Prihatiningsih, P.; Wahyono, A.; Jurami, J.; Prabowo, R. Assessment of Water Pollution Levels in Lake Batur, Indonesia and Their Effect on Water Weed Presence. Philipp. Agric. Sci. 2025, 108, 50–62, doi:10.62550/HL20058024.
68. Garno, Y.S.; Prayogo, T.; Dewa, R.P.; Widodo, L.; Riyadi, A.; Susanto, J.P.; Iskandar, I.; Kendarto, D.R.; Haryanti, H.; Adhi, R.P.; et al. Impact of Anthropogenic Activities on Water Quality, Pollutant Diffusion in Lake Waters, and the Level of Eutrophication: The Case of Batur Lake, Indonesia. Pol. J. Environ. Stud. 2026, 35, 1–15, doi:10.15244/pjoes/204003.
69. Hinanto, A.R.; Widyastuti, M.; Haryono, E. Assessing the Effectiveness of CCME-WQI, NSF-WQI, OWQI, and Smith Index Water Quality Indices in Karst Areas. Jurnal Ilmu Lingkungan 2024, 22, 1255–1262, doi:10.14710/jil.22.5.1255-1262.
70. Gidudu, A.; Letaru, L.; Kulabako, R.N. Empirical Modeling of Chlorophyll a from MODIS Satellite Imagery for Trophic Status Monitoring of Lake Victoria in East Africa. J. Great Lakes Res. 2021, 47, 1209–1218, doi:10.1016/j.jglr.2021.05.005.
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